Recurrent Squamous Cell Carcinoma of the Breast with Undifferentiated Features: Report of a Case

Abstract

Squamous cell carcinoma of the breast is a rare type of cancer, the origin of which is still uncertain. We report a case of squamous cell carcinoma of the breast with a recurrent tumor that showed undifferentiated features. The patient was a 55-year-old woman who originally presented with a left breast mass in the upper outer quadrant. Echography showed a 46 x 29 x 23-mm mass with cavity formation, and aspiration cytology confirmed a diagnosis of squamous cell carcinoma. A modified radical mastectomy with level III lymph node dissection was performed. Pathologically, the tumor was composed of squamous cell carcinoma and noninvasive ductal carcinoma. A recurrent tumor showing undifferentiated features was detected in the left forechest 3 months after the operation, and tumorectomy with partial resection of the major and minor pectoralis muscles was performed. Despite intensive therapy including chemotherapy (CEF: cyclophosphamide, epirubicin, 5-fluorouracil) and irradiation (50 Gy), the patient died from pulmonary and skin metastases 20 months after her initial operation. The squamous cell carcinoma of the breast in this patient grew rapidly and her prognosis was poor. Immunohistochemical findings indicated the possibility that the squamous cell carcinoma developed from noninvasive ductal carcinoma of the comedo type, and that the undifferentiated cells from the site of recurrence developed from dedifferentiation of the squamous cell carcinoma.

Primary Squamous Cell Carcinoma Of The Breast: A Case Report And Immunohistochemical Features For Differential Diagnosis

“…Calcification or cystic changes can sometimes be seen radiographically. [4,5,7,8,10,17] Our patient's clinical and mammographic findings were similar to those described at recent reports.…”

“…[4] An alternate theory is that the tumor arises from foci of squamous metaplasia within a pre-existing adenocarcinoma of the breast. [3,17] Features of the presented case such as squamous metaplasia in nontumoral ductal epithelium and multiple small invasive SCC foci around the main invasive tumor mass and immunohistochemical findings all support the first theory which favors metaplastic background for the neoplastic development. Cytokeratin profile in our case, especially diffuse CK7, CK8, CK19 and focal CEA positivity gives support to ductal origin of the tumor.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Although its histogenesis is unclear, some authors suggest it may originate from complete metaplasia of ductal epithelium. [1,3,4,14] Development of SCC from metaplastic epithelium can also be considered as a complication of chronic breast inflammation, for example due to the presence of breast implants.…”

“…[1,2,4,7,8,[12][13][14][15]17] Squamous cell carcinoma tends to be somewhat larger at presentation than other types of breast carcinoma with more than half of the reported cases in excess of 5 cm in diameter. [5,7,[9][10][11][12]17] In our case, after the neo-adjuvant chemotherapy, the diameter of the tumor decreased to 5 cm. Calcification or cystic changes can sometimes be seen radiographically.…”

“…It may have been associated with DCIS or squamous metaplasia of ductal epithelium at the periphery of the invasive carcinoma, [2,4,6,12,17] Estrogen and progesterone receptors are almost always reported to be negative. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] c-erbB-2 is also usually not overexpressed or amplified but some cases with c-erbB-2 positivity have been seen. [3,6,18] Our patient's tru-cut biopsy specimen which was taken before the chemotherapy contained small tumoral areas with infiltrative cell groups having no keratin formation.…”