                            PUBLISHED

UNITED STATES COURT OF APPEALS
                FOR THE FOURTH CIRCUIT


MARTHA JANE PERRY, survivor of        
George Perry,
                        Petitioner,
                 v.
MYNU COALS, INCORPORATED/Hobet                   No. 05-1651
Mining Company; DIRECTOR,
OFFICE OF WORKERS’ COMPENSATION
PROGRAMS, UNITED STATES
DEPARTMENT OF LABOR,
                     Respondents.
                                      
                On Petition for Review of an Order
                  of the Benefits Review Board.
                           (04-694-BLA)

                       Argued: January 31, 2006

                      Decided: November 20, 2006

   Before WIDENER, WILLIAMS, and MOTZ, Circuit Judges.



Petition for review granted; order vacated and remanded with instruc-
tions by published opinion. Judge Widener wrote the majority opin-
ion, in which Judge Motz concurred. Judge Williams wrote a
dissenting opinion.


                             COUNSEL

ARGUED: Leonard Joseph Stayton, Inez, Kentucky, for Petitioner.
Jeffrey Steven Goldberg, UNITED STATES DEPARTMENT OF
2                     PERRY v. MYNU COALS, INC.
LABOR, Office of the Solicitor, Washington, D.C., for Respondent
Director, Office of Workers’ Compensation Programs. Christopher
Michael Hunter, JACKSON & KELLY, P.L.L.C., Charleston, West
Virginia, for Respondent MYNU Coals, Incorporated/Hobet Mining
Company. ON BRIEF: Howard M. Radzely, Solicitor of Labor,
Christian P. Barber, Counsel for Appellate Litigation, UNITED
STATES DEPARTMENT OF LABOR, Washington, D.C., for
Respondent Director, Office of Workers’ Compensation Programs.
Douglas A. Smoot, JACKSON & KELLY, P.L.L.C., Charleston,
West Virginia, for Respondent MYNU Coals, Incorporated/Hobet
Mining Company.


                              OPINION

WIDENER, Circuit Judge:

   The issue in this case is whether George Perry, petitioner Martha
Jane Perry’s husband, died due to pneumoconiosis (Black Lung dis-
ease). The Administrative Law Judge, rejecting Mrs. Perry’s evi-
dence, held that Mr. Perry’s pneumoconiosis was not proven
complicated and, therefore, a statute and regulation creating an irre-
buttable presumption of causation did not apply. The Benefits Review
Board affirmed. Mrs. Perry questions the ALJ’s reasons for rejecting
the opinions of the doctors who testified that Mr. Perry had compli-
cated pneumoconiosis that caused his death. The federal respondent,
the Director of the Office of Workers’ Compensation Programs, joins
Mrs. Perry, at least so far as vacation and remand go, arguing specifi-
cally that the doctors’ testimony was sufficient to trigger the irrebutt-
able presumption of causation codified in 20 C.F.R. § 718.304 and 30
U.S.C. § 921(c)(3). We grant the petition and remand for an award of
benefits.

                                   I.

                                   A.

  Our summary of the medical evidence and the ALJ’s holding will
benefit from a general understanding of the difference between simple
and complicated pneumoconiosis.
                      PERRY v. MYNU COALS, INC.                       3
   In the explanation adopted by the ALJ, Dr. David Rosenberg, one
of Mynu Coals’ witnesses, summarized the difference as follows:

    [S]imple coal workers’ pneumoconiosis . . . is where you
    have micronodules that are discrete and that have not come
    together into a conglomerate mass. The micronodules, as a
    B reader, you categorize the various micronodules into dif-
    ferent categories of "p," "q" and "r," and "r" would be up to
    10 millimeters in diameter. In simple CWP . . . one can see
    that these micronodules are discrete and have not come
    together in a conglomerate mass.

    With complicated CWP, what happens is that these individ-
    ual micronodules fuse together and the body forms an
    immunologic reaction where tissue is destroyed within these
    conglomerate masses. One gets necrosis or destruction, liq-
    uefaction of tissue. One loses all structure, and it becomes
    a completely destroyed homogeneous mass of tissue within.
    And this is quite common in complicated CWP. And one
    sees anthracotic pigment that’s dispersed throughout this
    necrotic mass of tissue.

    [B]asically the difference between simple and complicated
    disease is the absence of discrete micronodules in the com-
    plicated disease as the micronodules come together.

   Another of Mynu Coals’ experts, Dr. Richard Naeye, was of a
slightly different view. He testified that complicated pneumoconiosis
is not a fusion of simple nodules, but a different etiology.

   In either case, it is agreed that the size of the mass and the extent
of tissue destruction are considerations. This leads us to the Supreme
Court’s description of the two types of pneumoconiosis, which, of
course, we follow: "[s]imple pneumoconiosis . . . is generally
regarded by physicians as seldom productive of significant respiratory
impairment" whereas "[c]omplicated pneumoconiosis, generally far
more serious, involves progressive massive fibrosis [and] usually pro-
duces significant pulmonary impairment and marked respiratory dis-
ability, [which] may induce death by cardiac failure, and may
contribute to other causes of death." Usery v. Turner Elkhorn Mining
4                     PERRY v. MYNU COALS, INC.
Co., 428 U.S. 1, 7 (1976) (citing Surgeon General’s report). Some
doctors in this case — Drs. Naeye and Rosenberg — contradicted
slightly this generalization, for example by testifying that simple
pneumoconiosis can impair lung function, but they concurred that
complicated pneumoconiosis has "increased morbidity."

    With this background, we turn to the facts.

                                  B.

   George Perry worked primarily as a bulldozer operator at a strip
mine, and in a few other mining positions, for 42 years. He was
forced to retire in 1975 due to having failed a physical, which Mr.
Perry attributed to his pneumoconiosis. In addition to his mining
work, Mr. Perry smoked 1.5 to 2 packs of cigarettes per day for 35
or 40 years, though he stopped smoking at about the time he retired
30-some years ago. In 1992, Mr. Perry had a successful heart-bypass
operation. At least one physician seeing Mr. Perry for a surgical
follow-up in August 1992 noted a "history of coal workers pneumo-
coniosis," though the basis for this notation is unstated.

   In late 2000, in the months before he died, Mr. Perry was taken to
the hospital several times after experiencing trouble breathing. Mrs.
Perry testified before the ALJ that her husband was constantly on
oxygen. On January 10, 2001, Mr. Perry was again taken by ambu-
lance to the hospital for such breathing problems. There he received
oxygen for his breathing problems, but he died a few days later, on
January 13. The death certificate identifies acute cardiopulmonary
renal failure as the immediate cause of his death; and it lists coronary
artery disease, chronic obstructive pulmonary disease (COPD), and
chronic renal failure as contributing causes.

                                  C.

   Mrs. Perry filed a timely claim for survivor’s benefits under the
Black Lung Benefits Act, 30 U.S.C. § 901 et seq., and its implement-
ing regulations, 20 C.F.R. Parts 410, 718, and 727. Following a pro-
posed decision and award of benefits by the Director, Mynu Coals
objected and requested a hearing, which was granted. The record prin-
                      PERRY v. MYNU COALS, INC.                       5
cipally consists of the reports and deposition testimony of various
doctors, described below.

   After Mr. Perry’s death, an autopsy was performed by Dr. Paul F.
Mellen. Dr. Mellen is board certified in the anatomic, clinical, and
forensic branches of pathology; he was at the time employed by the
Charleston Area Medical Center and also served as a clinical profes-
sor of pathology at the University of West Virginia. Dr. Mellen testi-
fied that he had performed "a hundred or so" autopsies to evaluate for
pneumoconiosis. Dr. Mellen’s description of how he diagnosed com-
plicated pneumoconiosis was consistent with its defining characteris-
tics: he looked for "aggressive massive fibrosis or coal nodules,"
relying on whether a gross exam revealed anthracosis (blackening),
scarring, and "on dissection, black nodules measuring at least . . . two
centimeter[s]" in diameter. Dr. Mellen acknowledged that anthracosis
does not necessarily mean fibrosis, nor are pigmentation and size suf-
ficient; rather, "the usual gross appearance" and "significant lung
fibrosis" are necessary.

   Dr. Mellen’s autopsy report concluded that Mr. Perry suffered from
complicated pneumoconiosis in both lungs, mild COPD, and cancer
in the right lung. The diagnosis of complicated pneumoconiosis rested
on "marked anthracosis with advanced associated scarring of both
upper lobes." This was confirmed by a gross viewing as well as
microscopic. The nodules were not X-rayed. Consistent with his
report, Dr. Mellen’s testimony suggested, though not in so many
words, that Mr. Perry’s death was caused by complicated pneumoco-
niosis. More specifically as to the diagnosis, Dr. Mellen determined
that a 4-centimeter nodule in the right lung was a mixture of pneumo-
coniosis and cancer, and a 6-centimeter nodule in the left lung was
complicated pneumoconiosis, or as he otherwise characterized it,
"coal dust with fibrosis." Dr. Mellen’s conclusions were based on his
gross viewing of the lungs and confirmed by microscopic slides. This
was the testimony in support of Mrs. Perry.1
  1
   Dr. Perper’s report issued after the hearing and after Mynu Coals’
reports had been submitted. Mynu Coals’ experts then submitted letters
explaining why their opinions did not change.
6                    PERRY v. MYNU COALS, INC.
   Several doctors testified or issued reports contrary to Dr. Mellen’s
to the effect that pneumoconiosis did not cause Mr. Perry’s death.
Since the claim of error in this case concerns the ALJ’s reasons for
rejecting Dr. Mellen’s conclusions, which did not rest on these doc-
tors’ views, we briefly summarize this evidence. Dr. Everett Oester-
ling, Jr., and Dr. Richard Naeye opined that pneumoconiosis did not
contribute to the decedent’s death, but that death was attributable
respectively to arteriosclerosis and cancer. Dr. Oesterling found mod-
erately severe pneumoconiosis but determined that it did not impair
Mr. Perry’s pulmonary function. Dr. Naeye opined that the silica
crystals in Mr. Perry’s lungs—at least as reflected on the slides he
reviewed—were not toxic and that there was insufficient black pig-
mentation and necrosis for a diagnosis of complicated pneumoconio-
sis. Dr. David Rosenberg and Dr. W.K.C. Morgan, both board-
certified specialists and B-readers, also attributed death to a cause
other than pneumoconiosis, variously pulmonary edema with coro-
nary artery disease, renal failure, and cancer. Dr. Morgan thought it
significant that Mr. Perry had worked most of his career above-
ground, meaning that the dust he was exposed to would not have been
coal dust.2

   The ALJ summarized this evidence and found Mynu Coals’ experts
to be more credible than Dr. Perper, though he "ranked equally" the
various physicians. But, apparently owing to Dr. Mellen’s status as
the autopsy prosector, he treated and rejected Dr. Mellen’s views on
three grounds unrelated to Mynu Coals’ doctors: (1) that Dr. Mellen’s
statements with respect to the composition of the 4- and 6-centimeter
nodules and with respect to what size they would have been on an X-
ray were "equivocal"; (2) Dr. Mellen’s unfamiliarity with Mr. Perry’s
smoking history; and (3) Dr. Mellen’s failure to identify pneumoconi-
osis as a cause of death.

   Mrs. Perry appealed to the Benefits Review Board, which affirmed
the denial of benefits on the same grounds as did the ALJ.
    2
   We note, however, that below-ground work is not necessary for coal
dust or recovery under the Black Lung statutes. See Norfolk & Western
Ry. Co. v. Roberson, 918 F.2d 1144, 114850 (4th Cir. 1990), Roberts v.
Weinberger, 527 F.2d 600, 602 (4th Cir. 1975).
                     PERRY v. MYNU COALS, INC.                       7
                                  II.

   We review the findings of fact to determine whether they are sup-
ported by substantial evidence, and the legal conclusions de novo. See
Island Creek Coal Co. v. Compton, 211 F.3d 203, 207-08 (4th Cir.
2000). As fact-finder, the ALJ must consider and weigh all the evi-
dence presented. See 211 F.3d at 208-09. And the ALJ must explain
which evidence is relevant and why he credited the evidence he did.
See Sterling Smokeless Coal Co. v. Akers, 131 F.3d 438, 439 (4th Cir.
1997).

   In addition to these familiar standards, our decision is framed by
the Black Lung Benefits Act’s implementing regulations. A pneumo-
coniosis death benefits claimant must prove that a decedent died as
a result of the disease. See 20 C.F.R. §§ 718.1 & 718.205(a).3 This
means that the claimant must establish that the decedent had coal
workers’ pneumoconiosis as defined by the Act, 20 C.F.R. § 718.202,
that the disease arose from coal mine employment, 20 C.F.R.
§ 718.203, and that death was due to pneumoconiosis, 20 C.F.R.
§ 718.205. See Shuff v. Cedar Coal Co., 967 F.2d 977, 980 (4th Cir.
1992).

   As the ALJ observed, all the physicians in this case agreed that Mr.
Perry had some form of pneumoconiosis, so Mrs. Perry satisfied her
burden of proof on the existence of the disease. The ALJ also held
that Mr. Perry’s pneumoconiosis was presumptively caused by his
mine employment, a finding not challenged by Mynu Coals. Accord-
ingly, the first two elements of recovery are not at issue.

   What is contested is the element of causation. By regulation, there
are three ways to prove it. See 20 C.F.R. § 718.205(c). The first two
are if (1) "competent medical evidence establishes that pneumoconio-
sis was the cause of the miner’s death," or (2) "pneumoconiosis was
a substantially contributing cause or factor leading to the miner’s
death or where the death was caused by complications of pneumoco-
  3
   Mrs. Perry also had to show, and showed, that: (1) she was a surviv-
ing dependent of Mr. Perry, 20 C.F.R. § 718.1; (2) Mr. Perry was a coal
miner, 20 C.F.R. § 725.202; and (3) that Mynu Coals was a responsible
operator, 20 C.F.R. § 725.491-.495.
8                     PERRY v. MYNU COALS, INC.
niosis." 20 C.F.R. § 718.205(c)(1 & 2) (emphasis added). These are
essentially codifications of ordinary standards of proof, though the
latter shifts the burden somewhat in that pneumoconiosis qualifies if
"it hastens the miner’s death." Id. § 718.205(c)(5). In light of the med-
ical differences between the two forms of pneumoconiosis, which
form afflicted Mr. Perry is relevant to whether the disease was capa-
ble of causing, and whether it actually caused, his death under either
method.

   The third method, our main concern here, is the irrebuttable pre-
sumption of causation created by statute and regulation. See 30
U.S.C. § 921(c)(3) and 20 C.F.R. § 718.205(c)(3); see also E. Assoc.
Coal Co. v. Dir., OWCP, 220 F.3d 250, 255 n.1 (4th Cir. 2000) (not-
ing virtual identity between the statute and regulation). Specifically,
the presumption attaches if pneumoconiosis,

    (a) When diagnosed by chest X-ray . . . yields one or more
        large opacities (greater than 1 centimeter in diameter)
        and would be classified in Category A, B, or C in [one
        of 3 classification systems] . . . [or]

    (b) When diagnosed by biopsy or autopsy, yields massive
        lesions in the lung; or

    (c) When diagnosed by [other] means . . . would be a con-
        dition which could reasonably be expected to yield the
        results described in paragraph (a) or (b) of this section
        had diagnosis been made as therein described . . . .

20 C.F.R. § 718.304. Thus, by statute or regulation, an opacity of suf-
ficient size—if X-rayed, one centimeter; if not, one that is "massive"
—becomes a proxy for the tissue mass characteristic of complicated
pneumoconiosis. See E. Assoc. Coal Corp., 220 F.3d at 255 (referring
to this as "statutory complicated pneumoconiosis").

                                  III.

  The ALJ’s failure to apply the presumption of causation on the
basis of Dr. Mellen’s testimony wrongly confused the presumption
                        PERRY v. MYNU COALS, INC.                      9
with the other methods of proving death due to complicated pneumo-
coniosis. The ALJ’s single-sentence rejection of the presumption
illustrates this conceptual error: "Because I find that complicated
pneumoconiosis was not established, criterion (3) is not met." (JA
439) Criterion (3) refers to the presumption of complicated pneumo-
coniosis. This same mistake is repeated in the opinion of the Board,
as it affirms the ALJ’s finding that Mrs. Perry has not established the
evidence of complicated pneumoconiosis. Of course, the decision of
the ALJ, as repeated by the Board, is simply wrong. It does not
address the necessary premises of the statutory presumption but only
finds that since the conclusion was not otherwise proven, the pre-
sumption is not effective. The Director of Workers’ Compensation
has caught this error. He takes the position that the evidence in this
case is sufficient to prove that opacities greater than 1 cm in diameter
would have been shown by X-ray had X-rays been made so that the
presumption in 30 U.S.C. § 921(c)(3) would apply. Also, we note,
without contradiction, that the prosector of the autopsy, Dr. Mellen,
described massive lesions in both lungs, another statutory ground for
application of the presumption. Specifically, Dr. Mellen’s autopsy
report contains a notation of "multiple jet black nodules measuring up
to 4 cm" in the upper part of the miner’s right lung. Dr. Mellen further
describes a similar nodule measuring 6 cm in the upper left lung. Dr.
Mellen contrasts these findings with the follow-up observation that
the lower portions of the miner’s lungs are "densely anthracotic with-
out mass lesions." (Emphasis added.) These determinations by the
prosector are relevant evidence which may only lead one to conclude
that massive lesions were present in the upper part of the lungs suffi-
cient to trigger the presumption under (b) of 20 C.F.R. § 718.304.4
  4
    The Director does not rely on this finding. We think any such absence
is too glaring to omit.
  The final anatomical diagnosis in the autopsy pathology report itself
includes:
      "Complicated coal worker type pneumoconiosis:
      Advanced anthracosis with marked
      Fibrosis of both upper lobes (progressive massive fibrosis)."
And the Clinical-Pathological Summary provides in part:
      "[Coal worker type pneumoconiosis, complicated type, with pro-
      gressive massive fibrosis.]"
10                    PERRY v. MYNU COALS, INC.
   Put simply, both the ALJ and the Board have required the plaintiff
to otherwise prove that the miner suffered from complicated pneumo-
coniosis. And for that reason, they find that the statutory presumption
would not apply. Correctly what the plaintiff needed to prove were
the premises of the presumption and, if proven, the statute provides
the irrebuttable presumption of complicated pneumoconiosis.

   Furthermore, Dr. Mellen’s testimony supports the irrebuttable pre-
sumption under (a) of 20 C.F.R. § 718.304 on the basis of the size of
the nodules found in the miner’s lungs. Dr. Mellen testified that the
fibrous masses were four and six centimeters wide, in the right and
left lobe, respectively, and that they therefore would have been
greater than one centimeter had they been X-rayed. The ALJ’s basis
for rejecting Dr. Mellen’s testimony as equivocal was Dr. Mellen’s
statement that he was not "one-hundred percent sure" of his conclu-
sion. We disagree. Read in context, Dr. Mellen’s qualification was at
most an acknowledgment that uncertainty is part of medicine. A
refusal to express a diagnosis in categorical terms is candor, not
equivocation, and we are of opinion that it enhances rather than
undermines Dr. Mellen’s credibility. In contrast, the other doctors’
adamancy that their opponents were incorrect in all or nearly all
respects detracts from credibility.

   More importantly, Dr. Mellen was the only doctor to assess the size
of the nodules in gross and under a microscope. Even Mynu Coals’
doctors agreed that this gave him additional perspective they lacked.
For instance, Dr. Rosenberg acknowledged that conducting the
autopsy is the "gold standard" for diagnosing disease. Dr. Mellen also
testified that the microscopic slides, which he created, on which the
other doctors relied exclusively, and which were said to be of excel-
lent technical quality, were too small to encompass a cross-section of
the tissue and therefore were of limited utility. So, while Dr. Naeye

The use of the word massive by Dr. Mellen is obviously taken from and
is entirely consistent with the statute and regulation, and no reason is
given to believe that Dr. Mellen used the word massive in any other than
its ordinary sense as used by Congress. We have so decided that precise
point in E. Assoc. Coal Co. v. DOWCP, 220 F.3d 250, 259 (4th Cir.
2000).
                      PERRY v. MYNU COALS, INC.                        11
claimed that the slides did not support the gross diagnosis, which tes-
timony the ALJ did not cite to reject Dr. Mellen’s view, Dr. Naeye
had a partial picture, literally and figuratively. And while Dr. Naeye
"wonder[ed] how accurately" Dr. Mellen measured the lesions, he did
not opine about their measurement. For these reasons, Dr. Mellen’s
testimony about the size of the lesions (had they been X-rayed) was
uncontradicted.5

   Mynu Coals’ doctors maintained, however, that Dr. Mellen’s not
having Mr. Perry’s entire medical history was an offsetting disadvan-
tage. This testimony seems to be reflected in the ALJ’s statement that
Dr. Mellen’s opinion might not have been the same had he known
about Mr. Perry’s smoking history. This is surmise unsupported by
the record. Dr. Mellen stated that he had enough medical history to
diagnose, and he confirmed Dr. Rosenberg’s gold standard testimony
by explaining that, between medical history or a gross viewing, the
latter is better. Moreover, Dr. Mellen testified that he had identified
the cancer, which was common in smokers, and that he did not attri-
bute the cancer to coal-dust exposure.

   We also note that the ALJ’s justifications applied largely to the 4-
centimeter mass in the right lobe. Indeed, the ALJ’s discussion of the
6-centimeter mass in the left lobe consists of a one-sentence descrip-
tion of Dr. Mellen’s testimony as being that both masses "could be
comprised of coalescent smaller masses." This mischaracterizes the
import of what Dr. Mellen said, which was that "I thought that one
of them was a progressive massive fibrosis [PMF] and the other one
  5
    Despite the fact that at least four doctors testified on behalf of the
defendant, not one of them contradicted Dr. Mellen’s testimony that the
lesions, had they been x-rayed, would have appeared on such x-ray. He
was familiar with such a state of affairs from past experience. In his
deposition, he recited cases in which lesions appearing on x-rays, previ-
ously thought to be cancerous, upon autopsy turned out to be black lung.
No reason is given for rejection of Dr. Mellen’s opinion other than he
was not 100% certain, which reason is itself insufficient, as we have
explained. The nodules in this case are considerably larger than the 1.7
cm nodules in E. Assoc. Coal, so our statement in that case, that "We are
given no reason to believe that nodules of 1.7 cm would not produce x-
ray opacities greater than 1 cm," 220 F.3d 250 at 258, is applicable here.
12                   PERRY v. MYNU COALS, INC.
was a mixture of PMF, as well as lung cancer," and that "the left lung
had no cancer." At best, even if the ALJ were correct about the rele-
vance of composition to the presumption, Dr. Mellen’s testimony as
to the 6-centimeter mass was rejected too summarily. For all these
reasons, Dr. Mellen’s testimony was sufficient to trigger the presump-
tion. The refusal to so consider the same was an abuse of discretion,
which is a principal cause of our finding that the decision of the
Board is not supported by substantial evidence.

                                 IV.

   For the foregoing reasons, the petition for review is granted, the
Benefits Review Board’s order denying benefits is vacated, and the
case is remanded to the Board which will see to the entry of an appro-
priate order awarding benefits.

              VACATED AND REMANDED WITH INSTRUCTIONS

WILLIAMS, Circuit Judge, dissenting:

   I agree with the majority that substantial evidence does not support
the Benefits Review Board’s decision. Nevertheless, for the following
reasons, I disagree with the majority’s decision to remand with
instructions for the Board to see to the entry of an order awarding
benefits.

                                  I.

   Under 30 U.S.C.A. § 921(c)(3) (West 1986 & Supp. 2006), there
is an irrebuttable presumption that a miner was totally disabled at the
time of his death due to pneumoconiosis, or that his death was due
to pneumoconiosis, if the miner suffered from a chronic dust disease
of the lung and "(A) an x-ray of the miner’s lungs shows at least one
opacity greater than one centimeter in diameter; (B) a biopsy reveals
"massive lesions" in the lungs; or (C) a diagnosis by other means
reveals a result equivalent to (A) or (B)." Eastern Assoc. Coal Corp.
v. Director, OWCP, 220 F.3d 250, 255 (4th Cir. 2000); see also 20
C.F.R. § 718.304 (2006). "The condition described by these criteria
is frequently referred to as ‘complicated pneumoconiosis.’" Id.
                      PERRY v. MYNU COALS, INC.                        13
"[B]ecause prong (A) sets out an entirely objective scientific standard
— i.e. an opacity on an x-ray greater than one centimeter — x-ray
evidence provides the benchmark for determining what under prong
(B) is a massive lesion and what under prong (C) is an equivalent
diagnostic result reached by other means." Id. at 256 (internal quota-
tion marks omitted).

   In this case, there were no x-rays of Mr. Perry’s lungs. Instead, the
administrative law judge (ALJ) considered the opinions of Dr. Mel-
len, who was the autopsy prosector, and five other doctors who
reviewed Mr. Perry’s medical history and microscopic slides (made
by Dr. Mellen) of Mr. Perry’s lungs. Dr. Mellen determined from the
autopsy that there were lesions in Mr. Perry’s lungs that would show
up on an x-ray as an opacity greater than 1 cm, although he qualified
his opinion by saying that he was "not a hundred percent sure." (J.A.
at 78.) Four other doctors — Drs. Oesterling, Naeye, Rosenberg, and
Morgan — concluded that Mr. Perry had simple, not complicated,
pneumoconiosis. Only Dr. Perper agreed with Dr. Mellen that Mr.
Perry had complicated pneumoconiosis.

   In evaluating this evidence, the ALJ "discredit[ed]" Dr. Mellen’s
opinion that Mr. Perry had complicated pneumoconiosis because Dr.
Mellen did not note Mr. Perry’s lengthy smoking history and because
his opinion was "equivocal." (J.A. at 438.) The ALJ gave "less
weight" to Dr. Perper’s opinion because it relied on Dr. Mellen’s find-
ings without mentioning the fact that those findings did not include
Mr. Perry’s smoking history or explaining how knowledge of that his-
tory would have affected those findings. (J.A. at 439.) Having dis-
counted the two doctors’ opinions that were favorable to Mrs. Perry,
the ALJ concluded that she had "not proven that [Mr. Perry] had com-
plicated coal workers’ pneumoconiosis." (J.A. at 439.)

   I agree with the majority that the ALJ improperly discounted the
opinion of Dr. Mellen and, by extension, the opinion of Dr. Perper.
Although Dr. Mellen expressed some uncertainty in his opinion, that
is not a sufficient basis to discredit completely his opinion, for a "rea-
sonable medical opinion is not rendered a nullity because it acknowl-
edges the limits of reasoned medical opinions." Piney Mountain Coal
Co. v. Mays, 176 F.3d 753, 763 (4th Cir. 1999). The ALJ’s discredit-
ing of Dr. Mellen’s opinion is particularly troubling because, as the
14                   PERRY v. MYNU COALS, INC.
majority states, Dr. Mellen "was the only doctor to assess the size of
the nodules in gross and under a microscope," which gave him a per-
spective that the other doctors lacked. Ante at 10. The ALJ’s error of
discounting Dr. Mellen’s opinion means that he reached a decision
after considering only part of the evidence. His decision — and the
Board’s decision in affirmance — is therefore not supported by sub-
stantial evidence.

                                  II.

   Because the Board’s decision is not supported by substantial evi-
dence, we should vacate the Board’s decision and remand with
instructions for the ALJ to consider properly all the medical evidence
before making a new determination of whether Mr. Perry had compli-
cated pneumoconiosis. In determining a claim for black lung benefits,
"all relevant evidence shall be considered." 30 U.S.C.A. § 923(b). We
have repeatedly instructed ALJs to heed this command. In Eastern
Assoc. Coal Co., we said that the ALJ "must in every case review the
evidence under each prong of § 921(c)(3) for which relevant evidence
is presented to determine whether complicated pneumoconiosis is
present." 220 F.3d at 256. Evidence under each prong "must be con-
sidered and evaluated to determine whether the evidence as a whole
indicates a condition of such severity that it would produce opacities
greater than one centimeter in diameter on an x-ray." Id. (emphasis
added); see also Lester v. Director, OWCP, 993 F.2d 1143, 1145 (4th
Cir. 1993) ("To make . . . a determination [of complicated pneumoco-
niosis], the OWCP necessarily must look at all of the relevant evi-
dence presented." (emphasis added)). All of the relevant evidence
must be considered because otherwise the existence of complicated
pneumoconiosis "could be found even though the evidence as a whole
clearly weighed against such a finding." Island Creek Coal Co. v.
Compton, 211 F.3d 203, 209 (4th Cir. 2000). Nevertheless, rather than
vacating the Board’s decision and remanding for a new, proper con-
sideration by the ALJ of all the evidence, the majority weighs the evi-
dence itself, concludes that Dr. Mellen’s opinion triggers the
irrebuttable presumption of 20 C.F.R. § 718.304, and remands with
the instruction that Ms. Perry be awarded benefits. Ante at 9, 12.

  In this approach, my good colleagues ignore the limits placed on
a court’s power to decide a question that Congress has entrusted to
                      PERRY v. MYNU COALS, INC.                      15
an administrative agency. See, e.g., SEC v. Chenery Corp., 318 U.S.
80, 88 (1943) ("For purposes of affirming no less than reversing its
orders, an appellate court cannot intrude upon the domain which Con-
gress has exclusively entrusted to an administrative agency."). It is a
fundamental tenet of administrative law that a "judicial judgment can-
not be made to do service for an administrative judgment." Id. We
therefore generally must "remand a case to an agency for decision of
a matter that statutes place primarily in agency hands." INS v.
Orlando Ventura, 537 U.S. 12, 16 (2002) (per curiam). This rule rests
on the "basic proposition that a reviewing court may not decide mat-
ters that Congress has assigned to an agency." W. Va. Highlands Con-
servancy, Inc. v. Norton, 343 F.3d 239, 248 (4th Cir. 2003).

   In Ventura, for example, the Board of Immigration Appeals had
held that Ventura was not entitled to asylum because he did not fear
persecution on account of his political opinion. Ventura, 537 U.S. at
13. The Ninth Circuit reversed, finding that the record did show fear
of political persecution. The court went on, however, to also reject the
alternative argument that the Government had made before the immi-
gration judge, namely, that country conditions in Guatemala had
improved to the point that persecution was no longer likely. Id. The
Supreme Court summarily reversed. The Court noted that a court of
appeals is "not generally empowered to conduct a de novo inquiry
into the matter being reviewed and to reach its own conclusions based
on such an inquiry." Id. at 16 (internal quotation marks omitted). The
Court further explained that the administrative "agency can bring its
expertise to bear upon the matter; it can evaluate the evidence; it can
make an initial determination; and, in doing so, it can, through
informed discussion and analysis, help a court later to determine
whether its decision exceeds the leeway that the law provides." Id. at
17.

   Just as in Ventura, "every consideration that classically supports
the law’s ordinary remand requirement does so here." Id. at 16; see
also Gonzales v. Thomas, 126 S. Ct. 1613, 1615 (2006) (per curiam)
(summarily reversing in a case similar to Ventura because there
existed "no special circumstance . . . that might have justified the
[court’s] determination of the matter in the first instance," and the
court therefore should have "applied the ordinary remand rule" (inter-
nal quotation marks omitted)); W. Va. Highlands Conservancy Inc.,
16                   PERRY v. MYNU COALS, INC.
343 F.3d at 248-49 (vacating a district court order that attempted to
make de novo findings not made by the agency because the "question
was for the [agency] to decide, and the district court should have
remanded the matter to the [agency] for the appropriate factfinding").
In this case, it is for the agency, and the agency alone, to properly
examine all the evidence in order to make the initial determination of
whether the irrebuttable presumption should be triggered in favor of
Perry. In deciding that matter ourselves, the majority opinion imper-
missibly oversteps this court’s bounds.

                                 III.

  Although I agree with the majority that substantial evidence does
not support the Board’s decision, I believe that the majority oversteps
our review authority. Therefore, I respectfully dissent.
