Carcinoma of the neck showing thymic-like elements (CASTLE): report of a case and review of the literature

Carcinoma showing thymic-like elements (CASTLE) is a rare tumor affecting thyroid and neck soft tissues, which has to be distinguished from squamous cell and anaplastic thyroid carcinoma, because it has a better prognosis. We report a new case of CASTLE which occurred in a patient submitted to total thyroidectomy with central neck dissection. The tumor stained positively for CD5, which seems to be the most useful marker in the differential diagnosis. By the analysis of the 18 cases reported in literature, total thyroidectomy with selective modified neck dissection should be the treatment of choice and radiotherapy should be considered for patients with positive nodal status.     

Immunohistochemical heterogeneity of breast carcinomas negative for estrogen receptors, progesterone receptors and Her2/neu (basal-like breast carcinomas).

Basal breast carcinomas triple negative for estrogen receptors, progesterone receptors and Her2/neu breast carcinomas are more aggressive than conventional neoplasms. We studied 64 cases with immunohistochemistry, using 23 antibodies, to characterize diverse pathological pathways. A basal cytokeratin was identified in 81% of tumors and vimentin was identified in 55%. The mean Ki67 index was 46% (range, 10-90%). Coincident expression of p50 and p65, which suggests an active nuclear factor-kappaB factor, was present in 13% of neoplasms. Epithelial growth factor receptor (EGFR), insulin-like growth factor-I receptor (IGF-IR) or c-kit (CD117) was identified in 77% of tumors. Loss of protein tyrosine phosphatase was found in 14%, whereas Akt activation was present in 28%. Several differences were identified between two subtypes of basal breast carcinomas: the pure variant (negative S-100 and actin) was more frequently associated with 'in situ carcinoma' (P=0.019) and pBad overexpression (P=0.098), whereas the myoepithelial variant (positive S-100 or actin) showed more frequent tumor necrosis (P=0.048), vimentin expression (P=0.0001), CD117 expression (P=0.001) and activated caspase-3 (P=0.089). IGF-IR could be as important as EGFR for the growth of these neoplasms. Basal cell carcinoma has at least two subtypes with distinct microscopic and immunohistochemical features.