Aggressive congenital fibromatosis of the small intestine in the newborn. Report of a case and review of the literature.

A case of so-called congenital fibro(leio)myosarcoma of the small intestine in a 18-day-old female baby, treated only with surgical resection, was studied by immunohistochemistry and electron microscopy in order to investigate the proliferating cell type. The tumour cells showed positivity only for vimentin and CD 34 and were negative for smooth muscle actin, desmin, alpha-sarcomeric actin, factor VIIIR: Ag and S-100 protein. Ultrastructural findings showed oval nuclei with prominent nucleoli, rare intracytoplasmic mitochondria and well developed rough endoplasmic reticulum. According to histoimmunological and electron microscopy findings the proliferating cells were likely to be of fibroblastic origin. A 7-year follow-up showed a favourable clinical evolution thus confirming that surgical resection can be a sufficient therapeutic approach. The morphological findings and clinical behaviour suggest that more appropriate terminology for this tumour would be "aggressive congenital fibromatosis" which better highlights its local progressive invasion without metastases.

Congenital desmoid tumor of the scalp: a histologically benign lesion with aggressive clinical behavior.

Desmoid tumors are uncommon benign neoplasms of fibroblastic origin, frequently presenting in the abdomen or abdominal wall of adults. This tumor is well known to general surgeons and pathologists, but it has rarely been reported in the neurosurgical literature. We describe a neonate who presented with a right temporal subscalp tumor at birth. In spite of initial apparent total removal, the tumor recurred twice. We discuss the diagnostic pitfalls encountered in assessing this tumor and the difficulties in distinguishing, in the excised specimens, between desmoid and reactive fibrosis. We suggest that desmoid tumor should be considered in the differential diagnosis of scalp and calvarial masses in children. Complete excision is required to prevent recurrences, and sometimes a multidisciplinary team is needed to secure margin-free resection.