del(6)(q12q15) as the sole cytogenetic anomaly in a case of solitary infantile myofibromatosis.

We describe a case of light microscopically typical solitary, infantile myofibromatosis in a 6-month old boy. The myofibroblastic differentiation of the tumor was supported by immunohistochemical and ultrastructural analyses. Cytogenetic and FISH analyses revealed a pseudodiploid karyotype with an interstitial deletion of the long arm of one chromosome 6, del(6)(q12q15), as the sole anomaly. The results demonstrate the usefulness of cytogenetics and FISH in distinguishing this type of lesion from infantile fibrosarcoma. To the best of our knowledge this is the first cytogenetic analysis of solitary infantile myofibromatosis.