Post-biopsy MRI changes in the size and enhancement of intramuscular myxomas: A report of two cases

Intramuscular myxomas are benign soft-tissue tumors, characterized by bland spindle-shaped cells and fibroblasts within an abundant mucoid matrix on histologic examination. Classically, these are slowly enlarging masses which may occasionally cause pain, paresthesia, and muscle weakness secondary to mass effect. We present an interesting phenomenon of two histologically confirmed cases of intramuscular myxomas that exhibited size and enhancement changes on follow-up imaging after image-guided biopsy. To our knowledge, this is the first report to describe size and enhancement changes of intramuscular myxomas after biopsy.