SQUAMOUS-CELL CARCINOMA OF THE BREAST - A CLINICAL APPROACH

Background: Squamous cell carcinoma (SCC) of the breast is rare. It re mains unclear whether a ''pure'' form of SCC exists or if all known ca ses actually represent an extreme form of squamous metaplasia within a denocarcinoma. Due to its rarity and controversy over its definition, there are no good data on appropriate management and prognosis. Method s: All cases of breast carcinoma indexed at our institution were revie wed to identify seven cases where squamous metaplasia was a significan t component of the pathologic diagnosis. Slides and electron micrograp hs were reviewed by a single pathologist. Clinical information was obt ained from medical records. Results: These cases support the concept o f a disease continuum with varying degrees of squamous metaplasia. Whe n tumors identified as ''pure'' SCC on light microscopy are subjected to ultrastructural analysis, either separate squamous and glandular ce lls are present or both histologic features are noted to coexist in th e same cell. Conclusions: Identification of ''pure'' cases of SCC appe ars clinically unimportant. All patients presented with advanced disea se, thus necessitating aggressive management regardless of histology. Mastectomy was performed due to large tumor size and adjuvant chemothe rapy given rather than hormones because of receptor negativity. The mi xed histology should direct future drug choice. The role of radiation remains unclear.