Fibromatosislike metaplastic carcinoma of the breast as a diagnostic pitfall for fine needle aspiration cytology: a case report.
BACKGROUND Metaplastic carcinomas of the breast are uncommon, and most display marked cellular atypia. Recently, a low grade fibromatosis-like metaplastic carcinoma was found and displayed little nuclear atypia. CASE A 74-year-old woman presented with a 2.5-cm, palpable breast nodule. Mammogram was reported as suspicious for malignancy. Cytologic examination revealed smears of low cellularity with most cells lying in clusters and having a round or oval shape. Rare cells had a "spindle" shape. Nuclear features were low grade. Rare individual cells had retained cytoplasm. Lumpectomy revealed a fibromatosis-like metaplastic carcinoma.


CONCLUSIONS
Cytologically, fibromatosis-like metaplastic carcinomas are low grade lesions producing smears of relatively low cellularity. Separation from ductal carcinomas is necessary because fibromatosis-like metaplastic carcinomas rarely metastasize to lymph nodes.
Jarboe
Elke
E
Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112, USA.
Layfield
Lester J
LJ
Collins
Brian
B
D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D044963:Biopsy, Fine-Needle; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000473:pathology*; D003581:Cytodiagnosis; D005260:Female; D005350:Fibroma / Q000473:pathology*; D006801:Humans; D008679:Metaplasia / Q000473:pathology
D014408:Biomarkers, Tumor