Metaplastic carcinoma of the breast with squamous differentiation: prognostic factors and multidisciplinary treatment

Background The objective of this study was to analyze the characteristics of patients diagnosed with metaplastic carcinoma of the breast with squamous differentiation and to identify the particular clinical and histological characteristics that need to be taken into account in this type of tumors. Case presentation Retrospective observational study of two patients managed at our hospital between 2014 and 2020 (15 months mean follow-up), plus all cases published in the last 7 years (8 patients). Thus, a total of 10 cases were analyzed, all with less than 2 years mean global survival. Studied variables were: age, medical background, tumor size, axillary involvement, radiological characteristics, surgical approach, complementary treatments, histologic characteristics, and progression of the disease. In 50% of cases, the disease appeared as a palpable mass of rapid growth, associated with axillary infiltration; 80% of the tumors were triple negative; 30% of them progressed to distant metastatic disease in 30%. Conclusions This unusual carcinoma requires a complex multidisciplinary treatment. Its prognosis is unfavorable due to its high local aggressiveness, with rapid progression and appearance of metastatic disease. The predominance of different histological components may determine the response to medical treatments.