[Primary intracystic squamous cell cancer of female breast]

We report on a 45-year-old patient who presented with a 7 cm palpable right breast mass which had been classified as a cyst by ultrasonography. Multiple aspiration cytologies revealed no evidence of malignancy. Repeat sonography in our institution showed a lesion at 1 o'clock, 1 cm deep, and 3-8 cm from the nipple. The lesion contained a solitary cystic component measuring 3.9 x 4.1 x 4.4 cm. A 3.1 x 2.6 x 2.5 cm solid, inhomogeneous mass with irregular margins was found at the lateral border of the cyst. This mass raised suspicion of an intracystic carcinoma. Histopathologic analysis of 5 high-speed biopsy tissue cores demonstrated an invasive large-cell ductal carcinoma (G2-3). Final histopathologic assessment subsequent to breast-preserving resection and axillary node dissection confirmed the initial diagnosis: keratinizing intracystic squamous cell carcinoma (G2-3, pT2, pN0 (0/15)). The search for a remote primary squamous cell carcinoma included a chest X-ray, cystoscopy, colposcopy and PAP smear, esophago-gastroscopy, ENT consultation (laryngoscopy), and did not reveal any extramammary cancer. The postoperative management consisted of a total of 6 cycles of chemotherapy (Cisplatinum 75 mg/m (2) BSA and Paclitaxel 175 mg/m (2) BSA every 21 days) and subsequent percutaneous radiotherapy. In accordance with published reports, the diagnostic and therapeutic management was analogous to that of adenocarcinoma of the breast. However, some authors recommend the same chemotherapy as used for squamous cell carcinomas of other organs. It remains difficult to make any statements regarding the adjuvant therapy and prognosis, since this type of tumor is so infrequent, especially as an intracystic lesion.