Challenges in the Recognition and Management of Metastatic Sarcomatoid Carcinoma Masquerading As Post-traumatic Hematoma.

Sarcomatoid carcinoma is an aggressive and rare form of cancer characterized by rapid metastatic spread and diagnostic complexity. This case describes a 68-year-old male presenting initially with persistent thigh swelling and pain following minor trauma. His symptoms were accompanied by systemic signs, including night sweats, constipation, abdominal pain, and dark stools. Despite persistent clinical deterioration, initial imaging suggested a benign etiology, such as hematoma or infection, leading to delayed diagnosis. Subsequent CT scans revealed significant intra-abdominal disease involving the bowel and omentum, with metastatic pulmonary involvement identified upon further imaging. Surgical exploration uncovered extensive metastatic sarcomatoid carcinoma originating from the lung, involving the bowel, omentum, and thigh soft tissues, necessitating extensive resection and complex bowel reconstructions. Immunohistochemical analysis confirmed pulmonary origin, highlighting the critical role of pathology in accurate diagnosis and treatment planning. Postoperative care was complicated by prolonged ileus, aspiration pneumonia, and persistent leukocytosis, requiring intensive multidisciplinary management. The patient's recovery emphasized the need for aggressive supportive care, early complication management, and psychological support following an unexpected diagnosis of advanced malignancy. Clinicians should consider metastatic malignancy when evaluating soft tissue lesions unresponsive to conservative management, especially if systemic symptoms are present. Early biopsy and definitive imaging interpretations are crucial for prompt diagnosis and improved outcomes. Comprehensive care strategies, including surgical intervention, multidisciplinary postoperative care, and psychological support, are essential for managing the complex challenges posed by metastatic sarcomatoid carcinoma.