Fibromatosis colli is a benign and rare disorder presented as a neck mass, appearing during the first weeks of life and it is often associated with congenital torticollis. It is a fibroblastic lesion that affects the sternocleidomastoid muscle, and varies in size from 1 to 3cm. We report three cases of neonates, two males and one female, 30 days-old, presenting a right cervical mass, in the sternocleidomastoid, measuaring 1,5cm each one. The major cytologic finding was loose benign fibroblasts and multinucleated cells consistent with degerating skeletal muscle fibers. None of the cases presented inflammatory cells. The cytological findings together with the clinical picture allow a definitive and accurate diagnosis of this entity, avoiding surgical biopsy, providing early initiation of conservative treatment, which will lead to resolution of the disease in the majority of the cases.
Fibromatosis; Fibromatosis colli; Fine-needle aspiration cytology
