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January 2003
IBD-like morphologic features in collagenous and lymphocytic colitis
Collagenous colitis (CC) and lymphocytic colitis (LC) are clinical
syndromes characterized by chronic watery diarrhea, few or no endoscopic
abnormalities and biopsies that typically show normal crypt architecture,
increased mononuclear inflammation in the lamina propria, absence
of neutrophils, and increased intraepithelial lymphocytes. Patients
with collagenous colitis also have a thickened subepithelial collagen
layer. The authors have noted, anecdotally, that biopsy specimens
from some patients with collagenous or lymphocytic colitis contain
certain histologic features, such as Paneth cell metaplasia, that
are normally seen in inflammatory bowel disease (IBD) or other types
of healed colitis and thus may cause diagnostic difficulty. The
purpose of this study was to evaluate the prevalence and significance
of IBD-like morphologic features in colonic mucosal biopsies from
patients with collagenous or lymphocytic colitis. Five hundred and
thirty-one routinely processed hematoxylin-and-eosin-stained colonic
mucosal biopsies from 150 patients with clinically, endoscopically,
and histologically confirmed collagenous colitis (79 patients; male:female
ratio, 14/65; mean age, 60 years) or lymphocytic colitis (71 patients;
male:female ratio, 13/58; mean age, 55 years) were evaluated in
a blinded fashion for a variety of histologic features. The results
were compared between collagenous and lymphocytic colitis and correlated
with the clinical and endoscopic data. None of the patients had
or developed IBD during the study period. Active crypt inflammation
was a common finding in both groups and was seen in 24 of 79 collagenous
colitis patients (30 percent) and 27 of 71 lymphocytic colitis patients
(38 percent). Surface ulceration was not seen in any of the lymphocytic
colitis biopsies but was present in two of 79 (2.5 percent) of the
collagenous colitis patients. Paneth cell metaplasia was frequent
in both groups but was more common in collagenous colitis patients.
Forty-four percent of collagenous colitis patients but only nine
of 63 (14 percent) lymphocytic colitis patients had Paneth cell
metaplasia (P<0.001). Crypt architectural irregularity
was present in six of 79 patients with collagenous colitis (7.6
percent) and three of 71 (4.2 percent) patients with lymphocytic
colitis. In patients with collagenous colitis, Paneth cell metaplasia
was associated with more severe disease characterized by the presence
of abdominal pain (P<0.001) and a higher frequency of bowel
movements (more than three bowel movements/day; P=0.06).
Also, active crypt inflammation correlated with antibiotic use at
the time of clinical presentation (P=0.04) and was present
in the only two patients who had positive stool cultures (one each
for Campylobacter jejuni and Salmonella). None
of the other histologic findings correlated with any of the other
clinical or endoscopic features. Pathologists should be aware that
some histologic features normally associated with IBD, such as crypt
irregularity and neutrophilic cryptitis and crypt abscesses, are
not uncommon in patients with collagenous or lymphocytic colitis.
The presence of one or more of these features should not necessarily
be interpreted as evidence against either diagnosis.
Ayata G, Ithamukkala S, Sapp H, et al. Prevalence
and significance of inflammatory bowel disease-like morphologic features
in collagenous and lymphocytic colitis. Am J Surg Pathol.
2002;26(11):1414-1423.
Reprints: Dr. Robert D. Odze, Gastrointestinal Pathology Service,
Dept. of Pathology, Brigham and Women's Hospital, 75 Francis St.,
Boston, MA 02115; rodze@partners.org
Repeating IHC on
patient materials referred elsewhere
Immunohistochemistry is an important adjunctive test in diagnostic
surgical pathology. The authors studied the clinical significance
and outcomes of performing IHC on patients with a previous diagnosis
of cancer who were coming to the Fox Chase Cancer Center (FCCC),
a National Cancer Institute-designated national comprehensive cancer
center (NCCC), for treatment or second opinion, or both. The authors
assessed all outside surgical pathology slide review cases seen
at the FCCC during 1998 and 1999 in which IHC was performed. Cases
were divided into confirmation of outside diagnosis with and without
prior IHC performed by the outside institution (groups A and B,
respectively) and cases with a significant change in diagnosis with
and without prior IHC performed by the outside institution (groups
C and D, respectively). During 1998 and 1999, 6,678 slide review
cases were reviewed at the FCCC, with an overall significant change
in diagnosis in 213 cases (3.2 percent). IHC was performed on 186
of 6,678 (2.7 percent) slide review cases, with confirmation of
the outside diagnosis in 152 (81.7 percent) cases and a significant
change in diagnosis in 34 (18.3 percent) cases. Patient followup
was obtained in 32 of 34 cases with a significant change in diagnosis
(groups C and D), which confirmed the diagnosis in 26 of 27 cases.
(Followup was inconclusive in five cases.) The authors repeated
the identical antibodies performed by the outside institutions in
group D (37 antibodies) and group B (133 antibodies) with different
results in 48.6 percent and 13.5 percent, respectively (overall
nonconcordance rate, 21.2 percent). In group D, additional antibody
tests beyond that performed by the outside institution were needed
in 88.8 percent of cases to make a change in diagnosis. The authors
concluded that in the setting of a NCCC, reperforming or performing
IHC on cases with a previous diagnosis of cancer is not a duplication
of effort or misuse of resources. Repeating or performing IHC in
this setting is important in caring for and managing cancer patients.
Wetherington RW, et al. Clinical significance
of performing immunohistochemistry on cases with a previous diagnosis
of cancer coming to a national comprehensive cancer center for treatment
or second opinion. Am J Surg Pathol. 2002;26(9):1222-1230.
Reprints: Dr. Harry S. Cooper, Dept. of Pathology, Fox Chase Cancer
Center, 7701 Burholme Ave., Philadelphia, PA 19111; hs_cooper@fccc.edu
Observer variation
in encapsulated follicular lesions of the thyroid gland
Diagnosing and classifying follicular lesions of the thyroid remains
one of the more challenging areas in surgical pathology. Although
histologic definition of follicular thyroid lesions is readily available,
application of the diagnostic criteria and personal experience may
lead to disagreement among pathologists. To investigate interobserver
variation in the assessment of encapsulated follicular lesions,
eight pathologists (four American and four Japanese) reviewed the
same hematoxylin-and-eosin-stained slide of each of 21 cases of
thyroid lesions showing encapsulation and follicular growth pattern.
There was complete agreement in 10 percent of the cases. At least
seven pathologists agreed on the diagnosis in 29 percent of the
cases and at least six in 76 percent of the cases. American and
Japanese pathologists agreed among themselves in 33 percent and
52 percent of cases, respectively. The frequency of diagnosis of
adenomatous goiter among Japanese pathologists (31 percent) was
considerably higher than among American pathologists (six percent).
In contrast, the frequency of diagnosis of papillary carcinoma among
American pathologists (25 percent) was considerably higher than
among Japanese pathologists (four percent). The authors’ analysis
revealed three primary factors affecting observer variation: interpretation
of the significance of microfollicles intimately related to capillaries
within the tumor capsule; evaluation of what constituted the type
of nuclear clearing indicative of papillary carcinoma; and absence
of clear morphologic criteria for separating adenomatous goiter
and follicular adenoma. More explicit criteria for diagnosis are
necessary to reduce observer variation in encapsulated follicular
lesions.
Hirokawa M, et al. Observer variation of encapsulated
follicular lesions of the thyroid gland. Am J Surg Pathol.
2002;26(11): 1508-1514.
Reprints: Dr. M. Hirokawa, Dept. of Pathology, University of Tokushima
School of Medicine, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan;
hirokawa@basic.med.tokushima-u.ac.jp
Robotic telepathology
for frozen-section diagnosis
Telepathology is the practice of digitizing histological or macroscopic
images for transmission along telecommunication pathways for diagnosis,
consultation, or continuing medical education. The use of telepathology
is attractive because it allows pathologists to obtain immediate
consultation. Oftentimes, a solo pathologist is asked to provide
diagnostic services without the support of immediate second or expert
consultation during an intraoperative consultation. Previous studies
have addressed static versus dynamic imaging of specimens using
a variety of systems and communication pathways. The authors assessed
the validity of a Web-based telepathology system for frozen section
consultation within the Army Medical Department. The system studied
provided real-time, dynamic remote control of a robotic microscope
over standard Internet connections. For the study, 120 consecutive
frozen section cases were diagnosed at a distance using the system.
Intraobserver agreement between the telepathology diagnosis and
glass slide diagnosis was observed. Diagnostic agreement was 100
percent for a variety of specimens. The study found that such Web-based
telepathology systems help support pathologists located at distant
sites.
Kaplan KJ, Burgess JR, Sandberg GD, et al. Use
of robotic telepathology for frozen-section diagnosis: a retrospective
trial of a telepathology system for intraoperative consultation. Mod
Pathol. 2002;15:1197-1204.
Reprints: Dr. Keith J. Kaplan, Dept. of Pathology, Walter Reed
Army Medical Center, 6900 Georgia Ave. NW, Washington, DC 20307-5001;
keith.kaplan@na.amedd.army.mil
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