Histopathological Spectrum of Unusual Breast Lesions: A Seven Year Retrospective Review

Breast lesions are the heterogeneous diseases that encompass several distinct entities with remarkably different characteristics. While the more common forms of breast cancers are well recognized and understood better, there are many important unusual lesions and malignancies that are less known and less appreciated.

To highlight the spectrum, histomorphology and prevalence of unusual breast lesions in our tertiary care hospital.

The clinicopathological records of resected breast lesions submitted to histopathology department over the period of seven years from Jan 2009 to December 2015 were reviewed retrospectively. It was observational, retrospective and descriptive analysis of 473 resected breast lesions including excised, lumpectomy and modified radical mastectomy (MRM) specimens. The most common lesions like infiltrating ductal carcinoma (IDC) and infiltrating lobular carcinoma in malignant category and fibroadenoma, fibrocystic disease in benign category were excluded from the study. We encounter unusual breast lesions that were included in our study.

Out of total 473 resected specimens of breast, benign lesions accounted for 336 (71.05%) and malignant 136 (28.75%). The unusual findings were 5.48% in malignant category and 1.12% in benign category and one in intermediate/borderline category. In unusual malignant category, we found 8 types of rare tumors out of 12 unusual variants. In benign and intermediate lesions, we found 4 cases of unusual pathologies.

This study highlights the importance of histopathology in breast lesions not only in diagnosing the lesion but also in predicting the prognosis. There are more than a dozen variants of breast cancer which are less common. Our study highlights the spectrum, histopathology and prevalence of such unusual lesions in our centre.