Significance of collagenous and mucinous spherulosis in breast cytology specimens

Abstract

Spherulosis of the breast is a rare but distinct benign morphological entity. As there are few cytological reports of breast spherulosis, the significance of spherulosis among cytological specimens is unclear. The objective was to document cytological aspects of spherulosis. A total of 3491 consecutive breast fine needle aspiration cytology (FNAC) samples and 69 nipple discharge cytology samples were reviewed. Papanicolaou-stained slides with or without Romanowsky staining were analysed. The corresponding 1926 histological specimens were also reviewed. We detected 17 cases of collagenous spherulosis (CS) and/or mucinous spherulosis (MS) among 3560 breast cytology specimens (0.48%). All samples were from women, who varied in age from 22 to 69 years. CS and/or MS were present in 15 of 3491 FNAC specimens (0.43%) and in two of 69 nipple discharge cytology specimens (2.9%). Corresponding histological specimens were available for 14 of the 17 specimens. Of the 14 specimens, 12 consisted of intraductal papilloma, one of fibroadenoma, and one of fibrocystic change. There was no spherulosis among the 1251 cytological specimens of malignant diseases. Cytological evidence of spherulosis is a good indicator of intraductal papilloma.