Sweat Gland Carcinoma With Neuroendocrine Differentiation of the Areola as a Potential Clinicopathologic Mimicker of Male Breast Carcinoma and Syringocystadenocarcinoma Papilliferum

Abstract

Sweat gland carcinoma with neuroendocrine differentiation (SCAND) is a newly proposed tumor entity of primary cutaneous apocrine/eccrine adnexal tumor with neuroendocrine differentiation. The histopathologic variations are not yet well known. In this article, we present a case of SCAND mimicking male breast cancer and syringocystadenocarcinoma papilliferum. A 68-year-old man presented with a reddish 12-mm nodule on his left areola. No lymph node or distant metastases were observed. The patient was disease free 1 year and 9 months after the tumor was surgically resected but died of cerebral hemorrhage. Histopathological examination revealed a predominantly intradermal tumor with marked syringotropism, mimicking a component of mammary ductal carcinoma in situ. In addition, another tissue section displayed a cup-shaped papillated tumor with syringocystadenocarcinoma papilliferum-like features, which were also seen because of marked syringotropism. Diffuse immunoexpression of cytokeratin 7, cytokeratin 19, chromogranin A, synaptophysin, INSM1, estrogen receptor, carcinoembryonic antigen, epithelial membrane antigen, and GATA3 was observed in the tumor, but no BRAF immunoexpression was seen. The present case would help us to understand the histopathological variation and differential diagnosis of SCAND. The histopathological diagnosis of male breast cancer or syringocystadenocarcinoma papilliferum should be made by ruling out SCAND.

Recurrent GATA3 P409Afs*99 Frameshift Extension Mutations in Sweat-gland Carcinoma With Neuroendocrine Differentiation

“…1 Cases with other carcinomas, including breast cancers, were excluded from this study. Of 13 SCAND cases, 4 cases (cases 1, 10, 11, and 13) were previously investigated in other studies 1,4 and were reevaluated in this study. Of the 5 EMPSGC cases, 2 (cases 17 and 18) showed a combination with NEMCS.…”

“…Sweat-gland carcinoma with neuroendocrine differentiation (SCAND) is a new type of malignant cutaneous appendageal tumor proposed in 2022, 1 which was also labeled as low-grade neuroendocrine carcinoma of the skin 2 . SCAND usually occurs in the anterior trunk in middle-aged to elderly males 1–4 . Histopathologically, SCAND is an invasive carcinoma with frequent infiltrative growth, similar to neuroendocrine carcinoma in other organs; however, papillomatous epidermal hyperplasia, intraepithelial pagetoid spreading of tumor cells, and stromal mucin deposits are characteristic of this tumor-type.…”