Endocrine mucin-producing sweat gland carcinoma with regional metastases in an African American female

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

Sweat-gland carcinoma with neuroendocrine differentiation (SCAND) was recently proposed as a new cutaneous adnexal neoplasm with neuroendocrine differentiation; however, its genetics are not well known. Herein, we performed clinicopathologic and genetic analyses of 13 SCAND cases and 5 control cases of endocrine mucin-producing sweat gland carcinoma (EMPSGC). The SCAND group included 11 males and 2 females with a median age of 68 years (range, 50 to 80 y). All SCAND lesions occurred in the ventral trunk or genital area. Of the 13 SCAND cases, 9 and 5 exhibited lymph node and distant metastases, respectively. Three (23.1%) patients with SCAND died of the disease. In contrast, neither metastasis nor mortality was confirmed in the EMPSGC cases. Immunoexpression of the androgen receptor, c-Myb, and MUC2 was limited in SCAND, whereas EMPSGC frequently expressed these immunomarkers. GATA3 P409Afs*99 extension mutations were detected in 7 (53.8%) of the 13 SCAND cases, using Sanger or panel sequencing. All 7 SCAND cases with GATA3 mutations were located in the genital, inguinal, or lower abdominal regions, whereas 5 of the other 6 SCAND cases were located in the anterior upper to mid-trunk. No GATA3 mutations were detected in the EMPSGC cases (0/5, 0%). These clinicopathologic and genetic findings support SCAND as a tumor entity distinguishable from EMPSGC. In addition, the characteristic frameshift extension mutations in GATA3 contribute to the establishment of the tumor-type concept of SCAND.

Metastatic Endocrine Mucin-Producing Sweat Gland Carcinoma to the Lung: A Case Report

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is a rare, low-grade neuroendocrine neoplasm previously believed to be indolent in nature. There have only previously been six reported cases of metastases and none of thoracic structures. This case shows a metastatic EMPSGC in a 72-year-old male with a complex oncologic history and is the first reported case of metastases to the lung. As increased recognition of this entity continues to grow, it is important to consider it as part of the differential in mucinous and/or neuroendocrine neoplasms for appropriate management. This case adds to the oncologic literature by demonstrating a rare cutaneous neoplasm and emphasizing its metastatic potential.