Case Report: Duodenal neoplasm-induced panniculitis.

Panniculitis comprises a group of diseases characterized by inflammation of the subcutaneous fat, and may present as a distinctive cutaneous paraneoplastic syndrome. Herein, we describe a case of paraneoplastic panniculitis caused by a duodenal neoplasm. The 79-year-old man presented with painful erythematous subcutaneous nodules on the lower extremities without any gastrointestinal symptoms. Histopathological manifestations of the skin included fat necrosis, calcification, and ghost cells. Laboratory test results revealed significantly elevated serum lipase levels (4144.7 U/L). Imaging revealed a normal pancreas, but identified a duodenal tumor with liver metastases. The patient was diagnosed with panniculitis secondary to a duodenal neoplasm with hepatic metastases and died 3 months after diagnosis. This case highlights panniculitis as a warning sign of occult duodenal neoplasms, facilitating clinical diagnosis and intervention.