NUT-CARCINOMA INVOLVING TRIGEMINAL NERVE - A CASE REPORT

Abstract

NUT-carcinoma is a rare aggressive disease caused by BRD4/3‐NUT fusion that results in MYC upregulation. A 50-years-old male patient presented frontotemporal headache and paraesthesia, evolving with worsening headache, diplopia, ptosis and reduced visual acuity for at least 12 months. Clinical diagnosis was meningioma due to an expansive process in the right temporal fossa with hyperostosis and optic canal stenosis. Histological analysis revealed malignant neoplasm presenting cohesive blocks of basaloid cells with foci of abrupt keratinization and necrosis, with infiltration of dense connective tissue and bone marrow. Immunohistochemistry was positive for EMA, P63, INI1(retained), AE1/AE3, CK5/6, CK8-18, CD117 and NUT. In addition, Ki-67 was positive in 80% of the neoplasia. Therefore, the final diagnosis was NUT carcinoma. The patient is still alive at the last follow-up. This case highlights the importance of considering NUT-carcinoma in the provisional diagnosis for undifferentiated or poorly differentiated neoplasms and immunohistochemistry can aid diagnosis. NUT-carcinoma is a rare aggressive disease caused by BRD4/3‐NUT fusion that results in MYC upregulation. A 50-years-old male patient presented frontotemporal headache and paraesthesia, evolving with worsening headache, diplopia, ptosis and reduced visual acuity for at least 12 months. Clinical diagnosis was meningioma due to an expansive process in the right temporal fossa with hyperostosis and optic canal stenosis. Histological analysis revealed malignant neoplasm presenting cohesive blocks of basaloid cells with foci of abrupt keratinization and necrosis, with infiltration of dense connective tissue and bone marrow. Immunohistochemistry was positive for EMA, P63, INI1(retained), AE1/AE3, CK5/6, CK8-18, CD117 and NUT. In addition, Ki-67 was positive in 80% of the neoplasia. Therefore, the final diagnosis was NUT carcinoma. The patient is still alive at the last follow-up. This case highlights the importance of considering NUT-carcinoma in the provisional diagnosis for undifferentiated or poorly differentiated neoplasms and immunohistochemistry can aid diagnosis.