Change of Pathological Type to Metaplastic Squamous Cell Carcinoma of the Breast During Disease Recurrence: Case Report and Literature Review

Abstract

Background: Metaplastic squamous cell carcinoma (SCC) of the breast is a rare and heterogeneous group of primary breast malignancies. The etiology, pathogenesis, and proper treatment for this kind rare breast cancer are still unclear. Case presentation: We reported a case of a 55-year-old woman with a palpable lump in the inner quadrant of the right breast. She underwent a right breast mass resection and sentinel lymph node biopsy, which revealed that the tumor was an invasive ductal carcinoma, followed by four cycles of doxorubicin plus cyclophosphamide and four cycles of docetaxel as adjuvant chemotherapy, and then simultaneous integrated boost intensity modulated radiotherapy to the whole right breast. After 2 years' follow-up, she had biopsy-proven disease recurrence in the right breast, which revealed SCC, and a mammogram showed abnormalities in the lower inner quadrant of the right breast and left axillary lymph nodes. Then we performed bilateral breast modified radical mastectomy, which confirmed that the recurrent tumors were metaplastic SCC, followed by adjuvant chemotherapy and adjuvant radiotherapy of the left supraclavicular and apical axillary regions. There has been no recurrent or metastatic evidence in the 16 months' follow-up since the second surgery. Conclusion: This case report shows that evolution of pathology type in recurrent breast cancer after initial treatment is possible. Detailed pathologic and immunohistochemical analyses are needed for identification of this change. Surgery and adjuvant radiation and chemotherapy are appropriate treatments for recurrent primary SCC of the breast.

Primary Squamous Cell Carcinoma of the Breast. A Case Report with Review of the Literature

“…Squamous cell metastasis to the breast from lung, stomach, and skin is more common than primary squamous carcinoma of the breast (2). Although it is primarily seen in post-menopausal women, it can be observed in other age groups as in our case (7,8). Squamous cell carcinomas of the breast have bigger than adenocarcinomas of the breast that can reach up to 10 cm in size (7,9).…”

“…Although it is primarily seen in post-menopausal women, it can be observed in other age groups as in our case (7,8). Squamous cell carcinomas of the breast have bigger than adenocarcinomas of the breast that can reach up to 10 cm in size (7,9). Central cystic degeneration is common in tumors larger than 2 cm, and this cavity is filled with necrotic squamous debris (4).…”

“…There is no specific pattern in mammographic and ultrasonic imaging of squamous cell carcinoma of the breast. The diagnosis can only be made with a biopsy, which shows the presence of malignant squamous cells showing intercellular bridging in tissue samples (7). Depending on the squamous origin of the tumor, cytokeratin staining is often positive, while estrogen, progesterone receptors, and Her2 / neu are reported as unfavorable.…”

Recurrent Metaplastic Breast Cancer with Subtype Converted from Triple-Negative to HER2-Positive: A Case Report and Literature Review

“…In the case of our study, the remarkable observation was that there was a change in the molecular type during the treatment, namely, a conversion in HER2 status from negative to positive. We carefully reviewed previous studies and found that only a few of them mentioned changes in pathological types, 16 , 17 while none of these reports mentioned changes in molecular type. Miglietta et al highlighted that HER2 expression was highly unstable during disease evolution and reported that HER2 discordance was mostly driven by cases switching from HER2-negative to HER2-low.…”

Transformation from Small Cell to Squamous Cell Carcinoma in a Thymic Carcinoma Patient with a Durable Response to Anlotinib: A Case Report

“…It is possible that the patient’s primary cancer was mixed small cell and SCC because of intratumoral heterogeneity or sampling artifacts. Guo et al 8 reported a case of a recurrent breast cancer whose pathological type changed from invasive ductal carcinoma to metaplastic SCC. The authors’ hypothesis was that the tumor’s transformation into breast SCC was likely to be the result of the malignant transformation of breast cancer stem/progenitor cells.…”