ABSTRACT
BACKGROUND: Pleomorphic lobular carcinoma (PLC) with apocrine differentiation is a rare breast carcinoma, and its cytologic findings have not been reported before. CASE: A 75-year-old woman had a mass in and skin rash on the left breast. Apocrine carcinoma was suggested on aspiration cytology of the mass. The cytologic smears showed a small number of rounded to oval, atypical cells that were poorly cohesive and individually scattered. The cytoplasm was relatively abundant and contained coarse granules and dropletlike, orange granules (Lendrum's granules). The cell border was distinct. Some atypical cells had intracytoplasmic lumina. The nucleoli were round and prominent, and nuclear chromatin was finely granular. The background was clean. Histologically, the tumor cells proliferated mainly in an Indian file pattern and showed a concentric, targetoid pattern around the non-neoplastic ducts. The cytoplasm was abundant, eosinophilic, granular, positive for the periodic acid-Schiff reaction and diastase resistant. Immunohistochemically the tumor cells were positive for gross cystic disease fluid protein-15 (GCDFP-15) and negative for E-cadherin. Lendrum's granules showed positive expression of GCDFP-15 and lysozyme. CONCLUSION: PLC with apocrine differentiation and apocrine carcinoma may be cytologically confused. Poor cellularity, less cohesiveness, finely granular chromatin, a nonpolyhedral cellular outline and clean background indicate the former rather than the latter. It is important to be aware that PLC presents a variety of cytologic configurations.
