Carcinoma sebáceo de la mama; presentación de un caso y revisión de la literatura / Sebaceous carcinoma of the breast; case report and literature review

El carcinoma sebáceo de mama (CSM) es una neoplasia muy poco frecuente. De acuerdo con la clasificación actual de la OMS, el CSM se define como un carcinoma de la mama en el que sus células presentan diferenciación sebácea en al menos el 50% de las mismas y no existe ninguna relación con las glándulas sebáceas de los anejos de la piel. Acorde con esta definición tan solo encontramos 21 casos descritos en la literatura. Presentamos un nuevo caso de CSM junto a una revisión de características clínicas, anatomopatológicas y terapéuticas de esta rara estirpe tumoral de mama

Sebaceous gland carcinoma (SGC) is an exceedingly rare neoplasm. According to the WHO, SGC is defined as a breast carcinoma in which at least 50% of cells show sebaceous differentiation and there is no relationship with the sebaceous glands of the skin annexes. Only 21 reported cases in the literature fit this definition. We present a new case of this rare breast tumour, as well as a review of its clinical, histological and therapeutic features

Molecular diagnosis of dermatofibrosarcoma protuberans: a comparison between reverse transcriptase-polymerase chain reaction and fluorescence in situ hybridization methodologies.

Dermatofibrosarcoma protuberans (DFSP) is characterized by the presence of the t(17;22)(q22;q13) that leads to the fusion of the COL1A1 and PDGFB genes. This translocation can be detected by multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) or fluorescence in situ hybridization (FISH) techniques. We have evaluated the usefulness of a dual color dual fusion FISH probe strategy for COL1A1/PDGFB detection in a series of 103 archival DFSPs and compared the obtained results with RT-PCR analyses. FISH and RT-PCR were carried out on paraffin embedded tissue samples. Regarding the RT-PCR approach, all COL1A1 exons and exon 2 of PDGFB were evaluated. Sensitivity, specificity, positive and negative predictive values were assessed considering the histological diagnosis as the gold standard. We also analyzed the relationship between the genetic findings and the clinicopathological variables of the tumors. The COL1A1/PDGFB translocation was detected in 93% of DFSP. Both techniques showed a similar specificity (100%), but FISH was more sensitive than RT-PCR (90% vs. 72%). Regarding, clinicopathological features, a higher percentage of positive cells detected by FISH was significantly associated with the fibrosarcomatous DFSP variant (P < 0.001). Interestingly, all CD34 negative DFSP (n = 5) were positive for COL1A1/PDGFB translocation by both techniques. In conclusion, the majority of DFSP harbor the COL1A1/PDGFB translocation and FISH technique should be recommended as a routine diagnostic tool, especially in cases showing unusual histopathological subtypes and/or immunohistochemical features.