Cáncer de metaplásico de mama: revisión de dos casos clínicos / Metaplastic breast cancer: review of two clinical cases

RESUMEN El carcinoma metaplásico de mama es un tipo de cáncer infiltrante que asemeja un carcinoma de alto grado histológico, pero cuya incidencia es muy baja (< 1%). Desde el punto de vista anatomopatológico presenta un componente mixto epitelial y mesenquimal; siendo lo más característico su comportamiento clínico altamente agresivo junto con unas características anatomopatológicas, inmunohistoquímicas concordantes, como son el HER2/neu negativo, los receptores hormonales negativos, el tamaño tumoral grande y el alto grado histológico. Por todo ello, resulta de especial interés conocer esta entidad, con la finalidad de realizar un diagnóstico preciso y llevar a cabo un tratamiento adecuado en estas pacientes. En el presente artículo se presenta la revisión de dos casos clínicos de cáncer de mama metaplásico, diagnosticados y tratados en nuestro Hospital durante el año 2015 y 2018.

ABSTRACT The metaplastic breast cancer is a subtype of an infiltranting breast cancer and it's usually high grade. However it is a rare subtype of cancer (incidence <1%). This cancer has an epithelial and connective tissues, which has an epithelial invasor ductal breast cancer with high grade and sarcomas breast. The main characteristic of the metaplastic breast cancer is their high agressive behavior as clinical as anatomopathological, which immunohistochemical expression is like a triple negative breast cancer. Because of this we consider that their knowledge is very important with the purpose of being diagnosed in women. In this paper it is showed a revision of two cases of metaplastic breast cancer, whose diagnostic and treatment were reported in our Centre.

Diagnostic Dilemma in Metaplastic Chondroid Breast Carcinoma

Metaplastic breast cancer is a rare form of primary breast cancer. It contains a mixture of adenocarcinoma with metaplastic elements. It is important to differentiate with primary sarcoma of the breast which carries different treatment strategies and prognosis. A 55-year-old lady previously diagnosed to have a left breast cancer in the year 2000 and carcinoma of the endometrium in 2009, presented with a right breast lump. A trucut biopsy reported as an infiltrating ductal carcinoma with background of chondromyxoid and cartilagenous matrix, most probably metaplastic carcinoma. A wide local excision with sentinel lymph node biopsy was performed, and the final histology was consistent with metaplastic chondroid carcinoma of the breast with no evidence of metastsis. The surgery was followed by adjuvant radiotherapy and currently free from any recurrence. The diagnostic dilemma on this very rare condition is reviewed.

A Locally Advanced Breast Cancer with Difficult Differential Diagnosis of Carcinosarcoma and Atypical Medullary Carcinoma, which had Poor Response to Adriamycin- and Taxane-based Neoadjuvant Chemotherapy: A Case Report / Journal of the Korean Cancer Association, 대한암학회지

Atypical medullary carcinomas and carcinosarcoma have unique histopathological features. Here we present a case with a breast malignancy that had pathological characteristics of both. A 54-year old patient with a malignant breast mass received 6 cycles of adriamycin-based chemotherapy, followed by 3 cycles of paclitaxel monotherapy, and had a poor clinical response to treatment. A modified radical mastectomy was performed. The pathological diagnosis was complicated by an inability to distinguish between atypical medullary carcinoma and carcinosarcoma. The findings included a tumor that was well-circumscribed, high grade and a syncytial growth pattern as well as biphasic sarcomatous and carcinomatous characteristics. In conclusion, atypical medullary carcinoma and carcinosarcoma of the breast have entirely different prognoses and should be managed differently. Both should be treated by surgical resection, and additional therapy should be considered based on the cancer with the poorer prognosis.