Four male cases of endocrine mucin‐producing sweat gland carcinoma: Specific gender differences in East Asia

1.

Endocrine mucin‐producing sweat gland carcinoma (EMPSGC) is a rare adnexal carcinoma of the skin with neuroendocrine differentiation. Histologic and immunohistologic features are analogous to those of solid papillary carcinoma in the breast and double‐positive for breast tumor markers, including estrogen receptor (ER), progesterone receptor (PgR), and GCDFP15, as well as neuroendocrine markers, for example, synaptophysin. Since the first report in 1997,1 a limited number of cases have been reported and it is considered to be seen more frequently in women. Here we report our experiences of four male cases.

Case 1 was a 70‐year‐old Japanese man with a pale red nodule 10 mm in diameter on his right upper cheek (Figure 1A), which emerged approximately 1 month earlier. An excision specimen revealed multiple lobules comprising monomorphic epithelial cells having no continuity with the epidermis (Figure 1D,E). Hematomas were observed in the lobules, which may correspond to a previously reported dermoscopic finding of “red/blue globules”2 (Figure 1F).

Figure 1.

The primary lesion in cases 1 (A), 2 (B), and 4 (C). Histopathologic features in case 1, macro hematoxylin & eosin (H&E), bar = 1.0 mm (D), high‐power H&E, bar = 100 μm (E, F). Histopathologic features in case 2 (G) and case 4 (H), high‐power H&E, bar = 100 μm. Immunohistochemical features of all four cases (table)

Case 2 was a 72‐year‐old Japanese man with a red nodule on his right cheek measuring 8 × 12 mm (Figure 1B). In this case, we observed an invasive lesion with decapitation secretion (Figure 1G) that was focally positive for synaptophysin.

Case 3 was a 53‐year‐old Japanese man with a purple nodule on his lower jaw measuring 4 mm in diameter (no picture available) that emerged 3 years earlier. The histopathologic and immunohistochemical features were similar to those in cases 1 and 2, with invasion and decapitation secretion.

Case 4 was a 66‐year‐old Japanese man with a pale pink nodule on his right cheek. The tumor cells were positive for CK7 and negative for CK20. An in situ component was observed in the sweat gland‐like structure (Fig. 1H), supporting its primary cutaneous origin.

The immunohistochemical features of all cases are summarized in the table. All of the cases were positive for ER, PgR, and synaptophysin. Extended resection with a 5‐mm margin was performed for cases 1‐3, and a 15‐mm margin in case 4. Recurrence was not observed in any case. All four cases arise on the face and three of them were on the cheek close to the eyelid. It is a typical clinical feature of this tumor. Seven cases of EMPSGC have been reported from East Asian countries (four cases from Japan and three cases from Taiwan).2, 3, 4 Interestingly, six of all seven cases are men in contrast to Caucasian cases which are two thirds women. Including Japan domestic reports (four men and one woman) and our cases (four men), this inclination become more evident. There seems to be racial differences of gender differences in the prevalence. It is considered that EMPSGC may be a precursor lesion of primary mucinous carcinoma of the skin (PMCS).5 Actually, three of our four cases (cases 2‐4) had invasive lesions appearing like PMCS with tumor cells floating in the extracellular mucin. A favorable outcome is reasonable if the EMPSGC is a precursor of a low grade malignant adnexal tumor. The contradiction of gender differences between EMPSGC and PMCS may be solved by further accumulate cases.

2. CONFLICT OF INTEREST

All authors declare no conflict of interest.

Nakamura M, Sakurai M, Ozawa H, Morita A. Four male cases of endocrine mucin‐producing sweat gland carcinoma: Specific gender differences in East Asia. Kaohsiung J Med Sci. 2020;36:467–468. 10.1002/kjm2.12203