Nodular fasciitis of the breast - Report of a case initially diagnosed by fine needle aspiration cytology

BACKGROUND: Nodular fasciitis is a rare benign pseudosarcomatous proliferat ion of fibroblasts iii the breast, in which the clinical examination mid ma mmographic findings may closely mimic mammary carcinoma. CASE: A case of nodular fasciitis was diagnosed by fine needle aspiration. A 15-year-old girl was admitted to our hospital with a recently noticed, ra pidly growing mass in the right breast. The aspirate contained cohesive gro ups of fusiform cells with elongated mid oval nuclei, regular nuclear membr anes and inconspicuous nucleoli, intermingled with scattered lymphocytes, r ed blood cells and characteristic granular background substance. A cytologi c diagnosis of nodular fasciitis was made and confirmed histologically. CONCLUSION: Mammary nodular fasciitis is often clinically suspicious for ca rcinoma and rarely diagnosed by fine needle aspiration cytology. A literatu re search yielded only five reported cases. The cytologic diagnosis of this entity helps to choose the correct surgical procedure, preventing psycholo gical trauma to the patient.