Bone-forming gastric metastases in muscle-computed tomographic demonstration.

Bone-forming metastases to soft tissues and muscle are a rare entity. An unusual case of heterotopic ossification occurring within metastases to muscle arising from a primary gastric adenocarcinoma is reported. No bone was found in the primary gastric malignancy. There is one prior report of ossification in muscle occurring in metastases from gastric malignancy, but no previous computed tomographic demonstration of this. The mechanism of osseous metaplasia is discussed, but its precise morphogenesis remains obscure.