Nodular fasciitis — Part II. A rare cause of a lump in the breast in a 44-year-old woman

Abstract

A 44-year-old lady presented with a 6 month history of a painless lump in the left breast. She was pre-menopausal with no family history of breast disease. She had been on the oral contraceptive pill for 2 years and breast fed one child. On examination there was a 1 cm solid nodule in the upper central portion of the left breast which was mobile and superficial and had the clinical features of a fibroadenoma. There was no associated lymphadenopathy. Fine needle aspiration cytology showed metachromatic stroma and benign pairs of ductal epithelial cells suggestive of fibroadenoma, but there was some degree of pleomorphism. The mammogram demonstrated an irregular density, 1.5 cm in diameter with a central lucency consistent with a sclerosing lesion (Fig. 1). In view of the pleomorphism seen in the cytology specimen, it was decided to excise the lump for histological examination. The excised lump appeared macroscopically as a firm white nodule 0.7 cm in diameter. The histology showed a focally storiform spindle cell proliferation with an infiltrative margin. The cytology of the spindle cells was bland and there was sparse mitotic activity, but no abnormal forms were seen. There were inflammatory cells and foci of mucoid change together with micro-haemorrhage. The appearances were those of nodular fasciitis (Fig. 2).