Nasal mucoepidermoid carcinoma lacking squamous immunophenotype:report of a case
LI Yongsen
SUN Tingting
HUANG Yousheng
CHENG Wende
Abstract：Objective To investigate the clinical and pathological features of mucinous epidermoid carcinoma (MEC) lacking squamous cell immunophenotype. Methods A case of nasal MEC in a 22-year-old male was collected, and the morphological features, immunohistochemical results, and molecular detection were observed. The findings were analyzed in combination with relevant literature. Results The patient presented with nasal bleeding, and imaging showed a nodule in the anterior nares. Microscopically, the tumor was arranged in nests, mainly composed of cells with clear cytoplasm, accompanied by mucin both inside and outside the cells, without obvious squamous differentiation. Immunohistochemistry showed that the tumor cells were positive for CK7, with only a few cells positive for CK5/6, and negative for p63, etc. PAS staining confirmed the presence of mucin. Molecular testing detected MAML2 gene rearrangement, and the pathological diagnosis was MEC. Conclusion MEC may lack morphological and immunophenotypic evidence of squamous differentiation, leading to misdiagnosis. Combined molecular testing is crucial for accurate diagnosis.
Keywords：Nasal tumorMucinous epidermoid carcinomaClear cellMAML2
Publication Date：2025-09-28
Online Publishing Date：2025-11-13(First online date of this platform, not the publication date of the document)
Pages：3( 1224-1226 )