Intraskeletal myofiber metastasis of breast carcinoma.

The authors report a case of chest skeletal muscle involvement by recurrent adenocarcinoma of the breast, in which individual myofibers were invaded by breast carcinoma cells. This unusual type of skeletal muscle involvement is especially interesting because it is known that the sarcolemma of skeletal myofibers is very resistant to enzymatic, mechanical, and chemical breakage.