COEXISTING BONE INFARCTION AND BONY METAS TASIS

A 42-year-old male patient presented with a history of persistent pain in the right femur without trauma of 2 months, duration and an episod e of bloody stools 3 months earlier with no clinical findings upon exa mination. X-rays and CT scan revealed a circumscribed lesion with scle rosis and periostal reaction in the right proximal femur. A three-phas e bone scan showed a massive hot spot in this area. Primarily differen tial diagnoses included a Brodie's abscess and/or a tumor. An excisona l biopsy of the area was performed and revealed the coexistence of a b one infarction and the metastasis of an adenocarcinoma of unknown orig in. The lesion in the bone was resected, filled with autogenous cancel lous bone and stabilized with a plate. Further intensive screening wit h CT of the abdomen, gastroscopy and colonoscopy led to the primary tu mor, an adenocarcinoma at the rectosigmoidal junction. No other metast ases were detected. This patient presented with severe pain an radiolo gically divergent finding: a presumably benign process on radiography, but a massive hot spot on scintigraphy Further procedures such as a C T scan and/or MRI had to be undertaken. If the analysis includes the d ifferential diagnosis of a malignant process, a biopsy must be obtaine d, and if this reveals a metastasis, the primary tumor must be sought.