Primary pulmonary mucoepidermoid carcinoma: a case report
- 1Department of Thoracic Surgery, Affiliated Hospital of Hebei University, Baoding, Hebei, China
- 2Department of Respiratory and Critical Care Medicine, Affiliated Hospital of Hebei University, Baoding, Hebei, China
Abstract
Primary pulmonary mucoepidermoid carcinoma(PMEC) is a rare salivary gland-type malignancy, accounting for fewer than 0.2% of all primary lung tumors. We report herein a 61-year-old male patient with PMEC who was admitted for a space-occupying lesion in the left upper lobe and had a 20-year smoking history. Contrast-enhanced chest CT and positron emission tomography-computed tomography (PET-CT) revealed a central space-occupying lesion in the left hilum with distal obstructive inflammation. Flexible bronchoscopy revealed a nodular mass in the left main bronchus. Biopsy histopathology combined with immunohistochemistry confirmed the diagnosis of PMEC. Immunohistochemistry showed CK7 (+), P63 (-), P40 (-), CD117 (focal+), TTF-1 (-), NapsinA (-), and Ki-67 (7%+). Molecular testing identified a CRTC1-MAML2 gene fusion, whereas no classic driver gene mutations (e.g., EGFR or KRAS) were detected. PD-L1 expression was negative, and the tumor mutational burden (TMB) was low. The low Ki-67 index and positive MAML2 fusion in this case suggest a low-grade PMEC with a relatively favorable prognosis. The present study discusses the clinicopathological features, imaging findings, molecular diagnosis, and therapeutic advances of PMEC, along with a review of the relevant literature, aiming to increase clinical awareness of this rare disease.
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BibTeX
@article{dong2026primary,
title = {{Primary pulmonary mucoepidermoid carcinoma: a case report}},
author = {Shaoyong Dong and Jing Sun and Ying Yang},
journal = {Frontiers in Medicine},
year = {2026},
month = oct,
doi = {10.3389/fmed.2026.1893850},
url = {https://doi.org/10.3389/fmed.2026.1893850},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Primary pulmonary mucoepidermoid carcinoma: a case report
AU - Shaoyong Dong
AU - Jing Sun
AU - Ying Yang
PY - 2026
DA - 2026/10/12
JO - Frontiers in Medicine
DO - 10.3389/fmed.2026.1893850
UR - https://doi.org/10.3389/fmed.2026.1893850
AB - Primary pulmonary mucoepidermoid carcinoma(PMEC) is a rare salivary gland-type malignancy, accounting for fewer than 0.2% of all primary lung tumors. We report herein a 61-year-old male patient with PMEC who was admitted for a space-occupying lesion in the left upper lobe and had a 20-year smoking history. Contrast-enhanced chest CT and positron emission tomography-computed tomography (PET-CT) revealed a central space-occupying lesion in the left hilum with distal obstructive inflammation. Flexible bronchoscopy revealed a nodular mass in the left main bronchus. Biopsy histopathology combined with immunohistochemistry confirmed the diagnosis of PMEC. Immunohistochemistry showed CK7 (+), P63 (-), P40 (-), CD117 (focal+), TTF-1 (-), NapsinA (-), and Ki-67 (7%+). Molecular testing identified a CRTC1-MAML2 gene fusion, whereas no classic driver gene mutations (e.g., EGFR or KRAS) were detected. PD-L1 expression was negative, and the tumor mutational burden (TMB) was low. The low Ki-67 index and positive MAML2 fusion in this case suggest a low-grade PMEC with a relatively favorable prognosis. The present study discusses the clinicopathological features, imaging findings, molecular diagnosis, and therapeutic advances of PMEC, along with a review of the relevant literature, aiming to increase clinical awareness of this rare disease.
SN - 2296-858X
ER -