To determine whether a subset of primary extramammary Paget disease (EMPD) may originate in anogenital mammary-like glands (AGMLG), the authors studied 181 specimens of EMPD, detailing alterations in AGMLG. The latter were identified in 33 specimens from 31 patients. All patients were women, ranging in age from 38 to 93 years (median, 65 y). In all cases, lesions involved the vulva and in 1 patient the perianal skin was affected. Histopathologically, AGMLG manifested changes identical to columnar cell change (CCC) (87.1%), usual ductal hyperplasia (22.6%), columnar cell hyperplasia (CCH) (9.7%), oxyphilic (apocrine) metaplasia (6.5%), and atypical duct hyperplasia (3.2%). Four cases (12.9%), in addition to intraepidermal carcinoma, harbored invasive carcinoma. In all 4 of these, AGMLG displayed a range of alterations including ductal carcinoma in situ, CCC, and CCH. Three further cases (9.7%) showed ductal carcinoma in situ without any definite invasive carcinoma. Colonization of AGMLG by neoplastic Paget cells was noted in 6 cases. As CCC and CCH may be encountered in normal AGMLG, these alterations are unlikely to play a significant role in the pathogenesis of the disease. However, by analogy with mammary Paget disease, rare cases of primary EMPD may originate in AGMLG with a subsequent upward migration of the neoplastic cells into the epidermis and possible later breach through the basal membrane. Usual ductal hyperplasia and atypical duct hyperplasia can then be regarded as earlier precursor lesions, linking both ends of the spectrum.
*Department of Pathology, Clinical Research and Practical Center for Specialized Oncological Care
†Department of Pathology, Medical Faculty, Saint-Petersburg State University
‡Department of Pathology, Saint-Petersburg Medico-Social Institute
∥∥Department of Dermatology, Medical Military Academy, Saint Petersburg, Russia
§PathWest Laboratory Medicine WA, QEII Medical Centre
∥School of Pathology and Laboratory Medicine, University of Western Australia, Nedlands
¶PathWest Laboratory Medicine WA, King Edward Memorial Hospital, Perth, WA, Australia
#Sikl’s Department of Pathology, Medical Faculty in Pilsen, Charles University in Prague
§§Department of Obstetrics and Gynecology, Charles University Medical Faculty Hospital, Pilsen, Czech Republic
††Miraca Life Science, Irving, TX
‡‡Department of Pathology, Division of Dermatopathology, Medical College of Wisconsin, Milwaukee, WI
¶¶Dermatopathology Unit, Department of Dermatology, Zurich University Hospital, Zurich, Switzerland
Supported in part by the SVV project 260 391.
Presented in part at the annual meeting of the United States and Canadian Academy of Pathology, San Antonio, TX, March 4 to 10, 2017.
Conflicts of Interest and Source of Funding: The authors have disclosed that they have no significant relationships with, or financial interest in, any commercial companies pertaining to this article.
Correspondence: Dmitry V. Kazakov, MD, PhD, Sikl’s Department of Pathology, Charles University Medical Faculty Hospital, Alej Svobody 80, 304 60 Pilsen, Czech Republic (e-mail: firstname.lastname@example.org).