Syringomatous Structures in Extramammary Paget Disease: A Potential Diagnostic Pitfall

Atypical Non-neoplastic Changes in Anogenital Mammary-like Glands Accompanying Invasive Squamous Cell Carcinoma

Long regarded as ectopic or supernumerary breast tissue, anogenital mammary-like glands (AGMLG) are now considered a normal constituent of the anogenital area. AGMLG are presumed to be the origin for various benign and malignant lesions. Changes in AGMLG compatible with usual ductal hyperplasia and atypical ductal hyperplasia considered as precursor lesions and its presence in specimens can be explained by their role in the pathogenesis of primary extramammary Paget disease. In this report, we presented four cases of invasive squamous cell carcinoma accompanied by non-neoplastic atypical changes in ductal portions of AGMLG compatible with atypical ductal hyperplasia in breast adjacent to the carcinoma. This is a reactive phenomenon similar to that seen in apocrine/eccrine glands adjacent to squamous cell carcinoma. In a limited biopsy specimen, these areas should not be mistaken for adenocarcinoma.

Extramammary Paget disease of the vulva

Extramammary Paget disease (EMPD) is a rare neoplasm with uncertain histogenesis, usually presenting in the anogenital area, most commonly in the vulva. The disease is characterized by slow grow and high recurrence rates. This article reviews the epidemiological, clinical, morphological, genetic and treatment features of EMPD of the vulva reported in recent years.

[Anogenital mammary-like glands and related diseases. Part 2. Malignant tumors of the anogenital glands]

Mammary-like glands are a normal anatomical component of the anogenital region and can give rise to many benign and malignant tumors that morphologically mimic the similar diseases of the breast. The literature review is complemented by a description of 199 cases of malignant tumors of mammary-like glands. The paper presents the clinical and morphological characteristics of various malignant tumors of mammary-like glands, including extramammary Paget's disease, ductal, tubulolobular, adenoid cystic adenocarcinoma, low-grade phyllodes tumor, etc.

Invasive Extramammary Paget Disease of the Vulva With Signet Ring Cell Morphology in a Patient With Signet Ring Cell Carcinoma of the Stomach: Report of a Case

This report describes a rare case of invasive extramammary Paget disease of the vulva with signet ring cell morphology in a 58-yr-old woman with a history of signet ring cell carcinoma of the stomach. This case was initially misinterpreted as a metastatic gastric carcinoma to the vulva because an initial small, superficial biopsy specimen showed infiltration of signet ring cells in the dermis without intraepidermal Paget cells. However, a surgically resected specimen showed concordant immunophenotypes in both intraepidermal Paget cells and intradermal signet ring cell components with immunoreactivity to cytokeratin (CK) 7, CEA, and gross cystic disease fluid protein-15, and immunonegativity for CK20, MUC5AC, and MUC6. Gastric signet ring cell carcinoma showed immunoreactivity to CK7, CEA, MUC5AC, and MUC6, and immunonegativity for gross cystic disease fluid protein-15 and CK20. The diagnosis of primary invasive extramammary Paget disease of the vulva was also supported by a long interval after gastrectomy (7.5 yr), the solitary involvement of the vulva, and the absence of lymphovascular invasion. This case demonstrates that invasive extramammary Paget disease may have a signet ring cell morphology and immunohistochemical profile similar to those of gastric signet ring cell carcinoma, but the addition of gross cystic disease fluid protein-15 immunostain in the panel of markers is helpful in the differential diagnosis.