Peritoneal mesothelioma presenting as a skin nodule

Area of Science:

• Oncology
• Pathology
• Dermatology

Background:

• Mesothelioma, a rare cancer affecting serous membranes, typically involves the pleura, pericardium, or peritoneum.
• Cutaneous manifestations of mesothelioma are exceptionally uncommon, posing diagnostic challenges.

Observation:

• A 75-year-old male with a history of significant asbestos exposure presented with a palpable mass on an old appendectomy scar.
• The abdominal wall mass was biopsied, revealing an infiltrating neoplasm in the dermis and subcutaneous tissue.

Findings:

• Histopathological examination identified an epithelioid and papillary neoplasm.
• Immunohistochemical analysis showed positivity for cytokeratin (CK) 7, CK 5/6, calretinin, and vimentin, while negative for CK 20, CEA, PSA, and PSAP.
• The immunoprofile confirmed a diagnosis of mesothelioma.

Implications:

• This case underscores the necessity of including cutaneous mesothelioma in the differential diagnosis for patients with asbestos exposure presenting with skin lesions.
• It emphasizes the importance of thorough patient history, including occupational exposures, in diagnosing rare malignancies.
• The findings contribute to the understanding of atypical presentations of mesothelioma.