Spindle cell lesions of breast: a retrospective analysis with emphasis on diagnostic challenges

Abstract

Background: Spindle cell lesions of breast comprise a rare group of complex entities which may be reactive, benign or malignant. Though definitive diagnosis is difficult especially in small biopsies, it is of utmost importance since the management differs. Precise knowledge of the lesions in this group, thorough sampling, clinic radiological correlation and ancillary techniques will aid in making the correct diagnosis. Review of literature showed only a few extensive studies on spindle cell lesions in breast, especially from South India.Methods: Our research is a descriptive histopathological analysis of 55 cases of spindle cell lesions of breast, done over a 2-year period from Jan 2015 to Dec 2016 in the Pathology department, of our institution.Results: A total of 55 cases were received. The reactive spindle cell proliferations were Diabetic mastopathy, Pseudoangiomatous stromal hyperplasia, and sclerosing adenosis. Benign phyllodes tumour, spindle cell lipoma and neurofibroma comprised the benign category. The malignant lesions included metaplastic carcinoma, malignant phyllodes tumour and sarcoma.Conclusions: Benign lesions constituted the majority (60%) in our study. Of these, benign phyllodes tumour constituted the majority, 41.8% of the total cases. The remaining 40% were malignant spindle cell neoplasms, of which metaplastic carcinoma was the single largest group accounting for 29.1%. Since reactive and benign spindle cell lesions may show atypia, definitive diagnosis should be made only after considering atypical mitotic figures, presence of necrosis and imaging findings. A wide excision with adequate margins is necessary in incision biopsies with suspicious findings.