Malignancy smells in the air: widespread eroded, hemorrhagic, and lichenified plaques in an older man

Paraneoplastic pemphigus (PNP) is a rare autoimmune mucocutaneous disease associated with underlying neoplasia. It is typically characterized by painful mucosal erosions and dark, patchy skin eruptions. A 66-year-old male was admitted to the internal medicine outpatient clinic with complaints of suddenly started rashes, loss of appetite, dyspepsia, weakness, and unexplained gross weight loss. The patient was cachectic and physical examination revealed widespread eroded, erythematous, thick-middle, yellow-pitted, lichenified plaques on bilateral arms and legs and the hands and feet dorsum. Scattered seborrheic keratosis lesions on the trunk were also detected. He had microcytic anemia with elevated CA 19-9 measures. Abdomen computed tomography showed a malignant mass in the antrum. Endoscopic biopsy of the gastric mass revealed poorly differentiated adenocarcinoma composed of discohesive signet ring cells and skin punch biopsy was compitable with paraneoplastic pemphigus. In patients with rapidly developing skin lesions with constitutional symptoms, underlying malignancies should be kept in mind.