Necrotizing Pneumonia, a Skeletal Muscle Lesion, and a Fungating Duodenal Mass: An Atypical Presentation of Rapidly Progressing Lung Adenocarcinoma.

Lung adenocarcinoma, the predominant subtype of non-small cell lung cancer, typically metastasizes to common sites such as the liver and adrenal glands. However, rare instances involve skeletal muscle metastasis. We present a case of a 45-year-old female with a medical history of hypertension, epilepsy, and fibromyalgia, who presented to the emergency department with hemoptysis and multifocal pain. Chest imaging revealed a cavitary lesion which appeared to be necrotizing pneumonia. Further investigations uncovered a fluid collection in the left thigh, which would be identified as poorly differentiated carcinoma. Subsequent testing identified the lung as the primary source of metastasis. Despite radiation treatment, the patient's condition deteriorated over the next 50 days, highlighting the aggressive nature of the disease.