Anatomic Abstracts

December 2007

Editor:
Michael Cibull, MD
Melissa Kesler, MD

Emerging eosinophilic esophagitis
Pathological assessment of pericolonic tumor deposits in advanced colonic carcinoma
Intracystic papillary carcinomas of the breast

Emerging eosinophilic esophagitis

Eosinophilic esophagitis is a disease of the esophagus with distinct histiologic features, such as prominent intraepithelial eosinophils (particularly superficial with clustering), and characteristic endoscopic features, such as trachealization and white plaques. The presence of intraepithelial eosinophils has been recognized as indicative of reflux esophagitis since 1982, but little attention initially was paid to their numbers or location. Recent reports have indicated that incidences of eosinophilic esophagitis are on the rise. This may result from environmental changes. To investigate the increased prevalence of eosinophilic esophagitis, the authors analyzed a similar group of cases from 2005 (n=150) and 1990 (n=115). The analysis included consecutive patients with mucosal esophageal biopsies from May through June of the respective years. The authors excluded patients with Barrett metaplasia or carcinoma. The highest density of intraepithelial eosinophils for each patient was recorded as the number of intraepithelial eosinophils per single high-power field. The patients were categorized by the number of intraepithelial eosinophils per high-power field, with those cases having more than 20 intraepithelial eosinophils per high-power field representing eosinophilic esophagitis. The authors found no difference in the incidence of eosinophilic esophagitis between 1990 and 2005. They concluded that the apparent increased incidence of eosinophilic esophagitis largely results from an increase in recognition rather than an increase in disease resulting from an environmental factor.

Vanderheyden AD, Petras RE, DeYoung BR, et al. Emerging eosinophilic (allergic) esophagitis: increased incidence or increased recognition? Arch Pathol Lab Med. 2007;131:777-779.

Reprints: Dr. Frank A. Mitros, University of Iowa, 200 Hawkins Drive, 5244B Roy Carver Pavilion, Iowa City, IA 52242-1009; frank-mitros@uioa.edu

Pathological assessment of pericolonic tumor deposits in advanced colonic carcinoma

The TNM (tumor-node-metastasis) classification considers a tumor nodule in the pericolic/perirectal adipose tissue as venous invasion if the nodule has an irregular contour and as regional lymph node metastasis if the nodule has the form and smooth contour of a lymph node. However, there are few detailed studies about the clinico-pathological implications of pericolonic tumor deposits and extranodal extension. The authors investigated the impact of these metastatic deposits in pericolic fat in a series of 228 patients with advanced colon cancer. The pericolonic tumor deposits were characterized by their appearance, size, distance from the primary tumor, and relation with the lymphatic tissue not organized in lymph nodes. These features were then compared with the clinico-pathological characteristics of the tumors and patient survival rates. All the lesions were associated with reduced disease-free and overall survival in a univariate analysis, but only pericolonic tumor deposits retained an independent prognostic role in multivariate analysis. The authors' findings suggest that pericolonic tumor deposits are different from other types of vessel involvement. Therefore the authors concluded that these lesions should be included in the M category for staging purposes.

Puppa G, Maisonneuve P, Sonzogni A, et al. Pathological assessment of pericolonic tumor deposits in advanced colonic carcinoma: relevance to prognosis and tumor staging. Mod Pathol. 2007;20:843-855.

Reprints: Dr. G. Pelosi, Divisione di Anatomia Patologica e Medicina di Laboratorio, Istituto Europeo di Oncologia, Via G Ripamonti, 435, I-20141 Milano, Italy; giuseppe.pelosi@ieo.it

Intracystic papillary carcinomas of the breast

Intracystic papillary carcinomas of the breast traditionally have been considered variants of ductal carcinoma in situ. However, it is not clear if all lesions categorized histologically as intracystic papillary carcinoma (IPC) are in situ carcinomas or if some of the lesions represent circumscribed or encapsulated nodules of invasive papillary carcinoma. Given that the demonstration of a myoepithelial cell (MEC) layer around nests of carcinoma cells is useful for distinguishing in situ from invasive carcinomas of the breast in problematic cases, assessing the presence or absence of a MEC layer at the periphery of the nodules that comprise these lesions could help resolve this issue. The authors studied the presence and distribution of MEC at the periphery of the nodules of 22 IPC and, for comparison, 15 benign intraductal papillomas using immunostaining for five highly sensitive markers that recognize various MEC components. The markers were smooth muscle myosin heavy chain, calponin, p63, CD10, and cytokeratin 5/6. All 22 lesions categorized as IPC showed complete absence of MEC at the periphery of the nodules with all five markers. In contrast, a MEC layer was detected around foci of conventional ductal carcinoma in situ present adjacent to the nodules of IPC. Furthermore, all benign intraductal papillomas, including those comparable in size to those of IPC, showed a MEC layer around the periphery of the lesion with all five MEC markers. The authors could not detect a MEC layer at the periphery of the nodules of any of the 22 lesions categorized histologically as IPC. One possible explanation for this is that these are in situ lesions in which the delimiting MEC layer has become markedly attenuated or altered with regard to expression of these antigens, perhaps due to their compression by the expansile growth of these lesions within a cystically dilated duct. Alternatively, it may be that at least some lesions that have been categorized as IPC using conventional histologic criteria represent circumscribed, encapsulated nodules of invasive papillary carcinoma. Regardless of whether these lesions are in situ or invasive carcinomas, outcome data indicate that they have an excellent prognosis with adequate local therapy alone. Therefore the authors believe it is prudent to continue managing patients with these lesions as they are currently being managed-that is, similar to patients with DCIS—and to avoid categorizing such lesions as frankly invasive papillary carcinomas. The authors favor the term encapsulated papillary carcinoma over intracystic papillary carcinoma for circumscribed nodules of papillary carcinoma surrounded by a fibrous capsule in which a peripheral layer of MEC cannot be identified.

Collins LC, Carlo VP, Hwang H, et al. Intracystic papillary carcinomas of the breast: a re-evaluation using a panel of myoepithelial cell markers. Am J Surg Pathol. 2006; 30:1002-1007.

Reprints: Dr. Laura C. Collins, Dept. of Pathology, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA 02215; lcollins@bidmc.harvard.edu