Radiation recall myositis: Two sites, one patient

A 63 year-old-man presented to his physician with worsening left shoulder and left hip pain. Magnetic resonance imaging (MRI) of the shoulder was concerning for metastatic disease to the left acromion. Biopsy of this lesion revealed metastatic adenocarcinoma. Positron emission tomography and computed tomography revealed areas of increased fluorodeoxyglucose uptake in a large pancreatic tail lesion as well as in the thoracic spine, left lung, and left acetabulum. Fine needle aspiration of the pancreatic lesion showed 2 distinct tumor types: adenocarcinoma (TTF-1 negative) and neuroendocrine neoplasm. Further immunostains or tumor markers could not definitively identify the primary origin of the tumor. The patient was evaluated by oncology and was diagnosed with stage IV adenocarcinoma with neuroendocrine features of unknown primary (lung vs pancreas) with metastases to the thoracic spine, left acromion, and left acetabulum. Examination of the shoulder revealed fullness of the left acromion and tenderness on palpation. The left hip was uncomfortable although he could ambulate. His pain was managed adequately with multiple opioids. The left hip and left acromion were treated with palliative intent radiation therapy (RT) to 30 Gy in 10 daily