Background

Metastatic melanoma (MM) is refractory to treatment, and patients with MM have a median survival of 6 months. A donor in the anatomy laboratory was reported to have MM as the cause of death. However, the findings were unique, suggestive of a rare presentation or a co-existing pathological entity. The case report explores the unique combination of cutaneous and visceral lesions that may be inadvertently interpreted to be of non-malignant etiology.

Methods

The study investigated the pathology noted in a 75-year-old female donor, with MM as the reported cause of death, during routine dissection in the anatomy laboratory. Detailed dissection, examination, biopsy, and histopathological examination (HPE) of the lesions were done. Photographs of the lesions on the skin and viscera were taken.

Results

Multiple slightly elevated lesions of 2-3 cm diameter were found on the gluteal region and anterior abdominal wall. Several firm and smooth nodules of around 1 cm diameter were found on the pericardium, pleura, peritoneum, diaphragm, lungs, heart, stomach, intestines, liver, spleen, kidneys, uterus, retroperitoneal region, and mediastinum. HPE of skin lesions showed basaloid proliferation and dermal hyperplasia. The visceral lesions showed multifocal tumors with small, loosely arranged eosinophilic cells and dense triangular nuclei. Immunohistochemical staining (pan-cytokeratin AE1/AE3, Melan A, and Ki-67) were performed, and the results are awaited.

Conclusions

The most common sites of metastasis of cutaneous melanoma are lymph nodes, liver, lungs, and brain; however, lesions were not found in the brain of this donor. Extensive visceral involvement and generalized distribution of nodules of MM may be inadvertently interpreted to be of non-neoplastic origin. In immunosuppressed patients, the multisystemic visceral lesions may be confused for granulomatous diseases such as sarcoidosis, brucellosis, histoplasmosis, or miliary tuberculosis. Since melanoma is immunogenic and more common in immunosuppressed patients, the clinical presentation warrants further evaluation.

Alternative title

• American Association of Neuropathologists, Inc. Abstracts of the 99th Annual Meeting June 8–11, 2023 Monterey, California

Creator

• Vila, Annabel

• Sakthi-Velavan, Sumathilatha

Publisher

• American Association of Neuropathologists

• Oxford University Press

Language

• English

Identifier

• DOI: https://doi.org/10.1093/jnen/nlad029

Keyword

• Metastatic melanoma (MM)

• co-existing pathological entity

• non-malignant etiology

• cutaneous and visceral lesions

Date created

• 2023

Related URL

• Available from the publisher:  https://academic.oup.com/jnen/article/82/6/489/7174288

Resource type

• Other

Source

• Journal of Neuropathology & Experimental Neurology (Vol.82, Iss.6, No.170)

Rights statement

• http://rightsstatements.org/vocab/InC/1.0/