Abstract
Background : We report the cytological findings in invasive lobular carcinoma with histiocytoid features compared to invasive lobular carcinoma, a typical pleomorphic variant.
Case 1 : An woman in her eightieth presented with a left breast tumor histologically diagnosed as invasive lobular carcinoma with histiocytoid features. Touch smear results had a few dispersed large foamy or granular cells with mildly enlarged smooth oval nuclei and mild to moderately increased chromatin. The specimen was negative for E-cadherin and positive for GCDFP-15.
Case 2 : A woman in her sixtieth presented with a right breast tumor histologically diagnosed as invasive lobular carcinoma with a pleomorphic variant. Touch smear results had a few large atypical cells with poor cohesion. Nuclei were irregularly shaped with a single large nucleolus. The specimen was negative for E-cadherin.
Conclusions : Cytologically, nuclear atypia in a pleomorphic variant is sufficient to detect malignancy, but exact classification requires E-cadherin immunohistochemistry. Nuclear atypia in a histiocytoid variant was less prominent than typical pleomorphic variant. In cases where malignancy is clinically suspected, cell atypia must be carefully evaluated to detect malignancy, and cytokeratin and E-cadherin immunocytochemistry are useful for accurate diagnosis.
