Twenty-one paraffin-embedded clear cell adenocarcinomas were immunohistochemically stained for bcl-2 (antibody M 887, Dako, Carpinteria, CA) and DNA fragmentation (ApopTag, Oncor, Gaithersburg, MD), a marker for apoptosis.
More recently, new categories have been defined, like secretory carcinoma with the t(12;15) (p13;q25) ETV6-NTRK3 translocation and clear-cell carcinoma with EWSR1-ATF1 fusion.
Reevaluation of MAML2 fusion-negative mucoepidermoid carcinoma: a subgroup being actually hyalinizing clear cell carcinoma of the salivary gland with EWSR1 translocation.
Recurrent gene fusions involving EWSR1 with members of the cAMP response element binding protein (CREB) family (ATF1 and CREB1) have been reported in a diverse group of tumors including angiomatoid fibrous histiocytoma (AFH), soft tissue and gastrointestinal clear cell sarcoma, primary pulmonary myxoid sarcoma, and hyalinizing clear cell carcinoma of salivary gland.
The EWSR1 rearrangement was detected in 20 of 51 (39%) cases of CCMC, in 5 of 21 (24%) cases of CCMCexPA, in 1 of 11 (9%) cases of EMC, and in 4 of 5 (80%) cases of hyalinizing clear cell carcinoma.
EWSR1-CREB1 and EWSR1-ATF1 are gene fusions of which one or both have now been consistently described in 5 histopathologically and behaviorally diverse neoplasms: angiomatoid fibrous histiocytoma, conventional clear cell sarcoma (of tendons and aponeuroses), clear cell sarcoma-like tumor of the gastrointestinal tract, hyalinizing clear cell carcinoma of the salivary gland, and primary pulmonary myxoid sarcoma.
A combination of NAPSA and ESR1 had a sensitivity of 97.9% (95% CI, 89%-99%) and specificity of 72.2% (95% CI, 46%-90%) for ESC versus clear cell carcinoma.
Positive napsin A immunostaining was more frequent in clear cell carcinoma, and there is a significant association between positive napsin A immunostaining and clear cell carcinoma (P-value=0.007).
We performed immunohistochemistry on 207 tumors [clear cell carcinoma (n=120), endometrioid carcinoma (n=49), and seromucinous tumors (n=38)], followed by two-color fluorescence in situ hybridization (n=88) and compared with ARID1A expression and hTERT promoter mutations in the same samples.
ARID1A mutations have been found in various types of cancer and occur at high frequency in endometriosis‑associated ovarian cancer, including clear cell adenocarcinoma and endometrioid adenocarcinoma, and also occur at endometrial cancer especially in endometrioid adenocarcinoma.
ARID1A mutations and loss of protein expression occur commonly in endometrioid and gynecological clear cell carcinoma where they are associated with mismatch repair (MMR) deficiency.
The past 3 years has seen a significant improvement in our understanding of clear cell carcinoma biology-in particular, the role of mutations in the chromatin remodelling gene ARID1A as key drivers that are common to clear cell carcinomas of ovarian and endometrial origin.
Napsin-A was positive for 87.5% of papillary renal cell carcinoma cases and in 29.4% of clear cell carcinoma cases and for 1 chromophobe renal cell carcinoma case.