Primary Squamous Cell Carcinoma of the Breast: a Case Report and Immunohistochemical Features for Differential Diagnosis

We present a 68-year-old postmenopausal woman with a rapidly growing right breast mass. It was diagnosed as “invasive ductal carcinoma” on tru-cut biopsy owing to infiltrative pattern and c-erbB-2 (HER2/neu) and progesterone receptor positivities. Partial response was obtained after four cure chemotherapy (adriamycin and cyclophosphamide). Then, she underwent a modified radical mastectomy with axillary lymph node dissection (level III). Grossly, a white-tan, solid, ill-defined tumor with 5 cm diameter located in the upper inner and outer quadrant of the breast was detected. Central portion of the tumor showed necrotic and hemorrhagic changes. Microscopic examination revealed poorly differentiated squamous cell carcinoma (SCC) having intraductal epithelial hyperplasia with squamous cell metaplasia and multiple small tumor foci at the periphery. The tumor had patchy necrotic, hemorrhagic and fibrotic areas representing regressive changes due to chemotherapy effect. Immunohistochemically, the tumor stained diffusely with CK7, CK8, CK19, HMW-CK and E-cadherin, whereas focally with CEA. Estrogenand progesterone receptors and c-erbB-2 were negative in the tumor. Five out of 20 lymph nodes dissected from the specimen were metastatic. Clinically, other organs were ruled out as the originating site of the tumor. She had taken oral chemotherapy (capecitabine) after surgery and has been living healthy for one year. Sag memesinde hizli buyuyen kitle yakinmasiyla basvuran 68 yasinda postmenopozal kadin hastaya tru-cut biyopsisi, lezyonun infiltratif yapisi ve immunohistokimyasal olarak c-erbB-2 (HER2/neu) ve progesteron reseptor pozitifligine dayanarak “invaziv duktal karsinom” tanisi kondu. Hasta dort kur kemoterapiye (adriyamisin ve siklofosfamid) kismi yanit verdi. Kemoterapi sonrasi modifiye radikal mastektomi ve aksiller lenf nodu diseksiyonu (level III) uygulandi. Makroskopik olarak ust ic ve dis kadranda 5 cm capli, kirli beyaz, solid, duzensiz sinirli, merkezi kismi nekrotik ve hemorajik tumor saptandi. Mikroskopik olarak kotu diferansiye skuamoz hucreli karsinom (SCC) niteligindeki tumor cevresinde skuamoz metaplazili intraduktal epitelial hiperplazi ve multipl kucuk SCC odaklari gozlendi. Tumor, kemoterapiye bagli regresyonu yansitan nekrotik, hemorajik ve fibrotik alanlar icermekte idi. Deri tutulumu izlenmedi. Immunohistokimyasal olarak tumorde CK7, CK8, CK19, HMW-CK ve E-cadherin diffuz, CEA fokal pozitifti. Ostrojen ve progesteron reseptorleri ve c-erbB-2 negatifti. Materyalden ayiklanan 20 lenf nodundan besi metastatikti. Klinik olartak skuamoz hucreli karsinomun gelisebilecegi diger organlar tarandi ve baska bir yerde herhangi bir tumor gorulmedi. Operasyon sonrasi oral kemoterapi (kapesitabin) alan hasta, bir yildir saglikli bir sekilde yasamini surdurmektedir.