Search

Background: There is concern about the oncological safety of preserving most of the breast skin in skin-sparing mastectomy (SSM). Most supportive evidence for SSM evaluates the local recurrence rate on clinical follow-up., Methods: The skin and 10 mm of the subcutaneous tissue of 30 total mastectomy specimens were studied with a step-serial sectioning technique. The incidence and mode of involvement of the skin and subcutaneous tissue were recorded in detail. This was correlated with other clinical and pathologic parameters., Results: The incidence of skin involvement outside the nipple-areola complex was 20% (6 of 30). This was significantly related to the clinical T stage, site of the tumor, skin tethering, pathologic tumor size, and perineural infiltration. When the effects of both skin and subcutaneous tissue involvement were considered, the incidence of skin-flap involvement outside the nipple-areola complex was 23% (7 of 30). The significant parameters related to skin-flap involvement were skin tethering (75% vs. 15%; P <.05), pathologic tumor size (P <.03), and perineural infiltration (63% vs. 9%; P <.01)., Conclusions: It would be oncologically safe to perform SSM in T1 and T2 tumors, because the chance of skin involvement is small. It is safe to preserve the skin overlying the tumor if there is no skin tethering.

An unusual example of mammary myofibroblastoma in a 36-year-old woman was reported. The central portion resembled mammary myofibroblastoma or solitary fibrous tumor of other sites and showed reactivity for CD34 and muscle-specific actin, with few cells staining for desmin. The peripheral portion resembled leiomyoma and showed strong reactivity for actin and desmin but only focal staining for CD34. We interpret this tumor as mammary myofibroblastoma showing frank peripheral leiomyomatous differentiation. Although closely related to solitary fibrous tumor, mammary myofibroblastoma appears slightly different because of its consistent slant toward myoid differentiation in the form of actin and variable desmin reactivity as opposed to the rare and sparse immunohistochemical expression of myoid features by solitary fibrous tumors of other sites. This case demonstrates this phenomenon carried to an extreme, a feature not previously documented in mammary myofibroblastoma. It is of interest to note the modulation of the antigenic profile with the differentiation process, that is, loss of CD34 and gain of desmin accompanying the myoid differentiation.