Pancreatitis, panniculitis, polyarthritis syndrome as an initial manifestation of metastatic pancreatic cancer in a breast cancer patient: Importance of early recognition and multidisciplinary management: A case report.

Pancreatitis, panniculitis, and polyarthritis syndrome is a rare extrapancreatic triad associated with pancreatic disease and occasionally malignancy. We report a 51-year-old woman with prior hormone receptor-negative, human epidermal growth factor receptor 2-positive breast invasive ductal carcinoma (bilateral mastectomy, adjuvant trastuzumab/pertuzumab, radiation) who developed abrupt painful erythematous nodules of both legs and progressive polyarthralgia of the hands, knees, and ankles. Symptoms were initially treated as inflammatory rheumatic disease with systemic corticosteroids and disease-modifying therapy without benefit, leading to severe functional decline. Imaging later revealed a large hepatic mass; biopsy confirmed metastatic pancreatic acinar cell carcinoma, unifying the presentation as pancreatitis, panniculitis, and polyarthritis syndrome. Coordinated multidisciplinary care, oncology-directed chemotherapy, interventional pain management, and psychological support, improved pain control and mobility. This case adds to the limited pancreatitis, panniculitis, and polyarthritis literature and highlights that absent gastrointestinal symptoms can delay diagnosis; early recognition and collaborative management are essential in malignant pancreatitis, panniculitis, and polyarthritis presentations.