A case of endocrine mucin-producing sweat gland carcinoma with distant metastasis

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.

Endocrine Mucin-Producing Sweat Gland Carcinoma: Case Presentation with a Comprehensive Review of the Literature

(1) Background: Endocrine Mucin-Producing Sweat Gland Carcinoma (EMPSGC) is a rare, low-grade, neuroendocrine-differentiated, cutaneous adnexal tumor, officially recognized by the World Health Organization (WHO) Skin Tumors Classification in 2018 as a separate entity and homologue of endocrine ductal carcinoma in situ (eDCIS)/solid papillary carcinoma of the breast. Although it is more frequent in the female sex, between 60 and 70 years old, in the peri-orbital region, EMPSGC has also been described in the male sex, in subjects under 60 and over 80, and in extra-eyelid localizations (cheek, temple, scalp), but also in extra-facial localizations (chest and scrotum). (2) Methods: We present the clinical case of a 71-year-old woman with an undated lesion of the scalp, which presented as a nodule, skin-colored, and 2.5 cm in maximum diameter. We also conduct a comprehensive literature review from 1997 to the end of 2022, consulting PubMed, Scopus, Web of Science (WoS), and Google Scholar using the following keywords: "Endocrine mucin-producing sweat gland carcinoma" and/or "EMPSGC" and/or "skin" and "cutaneous neoplasms". In addition, we followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A total of 253 patients were recorded; 146 were females (57.7%) and 107 were males (42.2%). The vast majority of the lesions were in the eyelids (peri-ocular region), and only a minority of cases involved the cheeks, supra-auricular, retro-auricular, and occipital region, with very rare cases in the scalp, to which the present is also added. (4) Conclusions: The morphological and immunophenotypical features are essential both for the correct diagnosis and to be able to classify this lesion among the corresponding eDCIS/solid papillary carcinoma of the breast, with neuroendocrine differentiation. Recent papers have attempted to shed light on the molecular features of EMPSGC, and much remains to be conducted in the attempt to subtype the molecular profiles of these entities. Future studies with large case series, and especially with molecular biology techniques, will be needed to further add information about EMPSGC and its relationship in the PCMC spectrum.

Cytological findings in a case of endocrine mucin-producing sweat gland carcinoma with metastasis to salivary glands

Endocrine mucin‐producing sweat gland carcinoma (EMPSGC) was previously considered an indolent skin tumour without metastasis. This report describes a case of metastatic EMPSGC affecting left parotid and submandibular glands, and its features on aspiration cytology.

Metastatic Neuroendocrine Tumors to Parotid Gland: Where Do They Come From?

Background. Metastasis to parotid gland occurs mostly from skin cancers of the head and neck region. Metastatic neuroendocrine tumors to the parotid gland are rare and not well studied so far. In this study, we undertook a retrospective review of secondary neuroendocrine tumors of the parotid diagnosed in our institution. The most common entities, primary tumor locations, their clinical presentations and histopathological features were analyzed. Methods. Cases of secondary neuroendocrine tumors to parotid diagnosed from August 1995 to Jan 2021 were retrieved from our institution's pathology databases, and their clinicopathological features were reviewed. Results. About 29% (120 of 420 cases) of parotid neoplasms were malignant, including 70 cases of parotid primary malignant tumors and 50 cases of metastases to parotid glands. Among metastatic tumors to the parotid glands, squamous cell carcinoma and melanoma of the head and neck region together accounted for about 78% of the cases. Only 11 of 50 metastatic tumors to the parotid were neuroendocrine carcinomas (22%). The most common primaries were poorly differentiated neuroendocrine carcinoma of lung (5 of 11 cases), including 4 cases of small cell carcinoma and one case of large cell neuroendocrine carcinoma. The second most common secondary tumor was Merkel cell carcinoma (4 of 11 cases, 36%) including one case of direct invasion from overlying skin. Medullary carcinoma of the thyroid comprised the rest of the metastases to the parotid (2 of 11 cases, 18%). Conclusion. Our results show that metastatic neuroendocrine carcinomas to the parotid gland account for about 22% of all metastatic tumors to the organ. Lung is the most common primary neuroendocrine carcinoma location. It is not uncommon for metastatic neuroendocrine carcinoma to present as the first sign of systemic clinical manifestation. Merkel cell carcinoma is the second most common entity that metastasizes to parotid, followed by medullary carcinoma of the thyroid.

Endocrine Mucin Producing Sweat Gland Carcinoma with Metastasis to Parotid Gland: Not as Indolent as Perceived?

Endocrine mucin-producing sweat gland carcinoma (EMPSCG) is a rare, low-grade cutaneous adnexal neoplasm with evidence of neuroendocrine differentiation, predominantly involving the eyelids of elderly. It has a striking resemblance to solid papillary carcinoma of breast which similarly displays neuroendocrine features. EMPSGC is considered a precursor of cutaneous mucinous carcinoma, and the term "mucinous carcinoma" is also recommended for hybrid lesions which reveal an invasive mucinous component associated with EMPSGC. While local recurrences are well- documented in EMPSGC, metastases had not been encountered until very recently; two reports in the past year have described metastases from eyelid EMPSGC to the parotid gland after a prolonged interval from the primary presentation. We report the case of a 78-year-old male with eyelid EMPSGC metastatic to the parotid gland nine years after excision of the primary tumor, which had initially been diagnosed as a poorly differentiated carcinoma. Development of metastasis after a prolonged interval is similar to both the previously described cases, and emphasizes the need to reevaluate the stated indolent nature of this neoplasm. It also aims to draw attention of pathologists to this uncommon tumor of the eyelid which is often misdiagnosed on primary presentation.