[Diagnostic and prognostic implications of MAML2 gene translocation in primary pulmonary mucoepidermoid carcinoma]

Objective: To investigate MAML2 gene-translocation in primary pulmonary mucoepidermoid carcinoma (PMEC) and pulmanary adenosquamous carcinoma, and the optimal diagnostic immunohistiochemical (IHC) panel in distinguishing PMEC from adenosqumous carcinoma. Methods: Twenty-four cases of PMEC and 44 adenosqumous carcinoma diagnosed in the Guangdong General Hospital were tested for MAML2 translocation by fluorescent in-situ hybridization (FISH) using tissue array. An IHC panel including TTF1, Napsin A, CK5/6, p63, p40 and Ki-67 was performed on the cohort. The clinical data for all cases were collected and all PMEC patients had follow-up information. Results: The patients' age ranged form 6 to 73 years, with a median age of 32 years. The male to female ratio was 1.4∶1.0. MAML2 translocation was found in 16/24 (66.7%) cases of PMEC whereas all 44 cases adenosqumous carcinoma were negative for translocation. All the cases of the PMEC were negative for TTF1 and Napsin A but positive for CK5/6, p63 and p40 in the intermediate cells and epidermal-like cells. In most PMEC cases, the Ki-67 expression index was lower than 10%. In contrast, most cases of adenosqumous carcinomas expressed TTF1 and Napsin A in the adenomatous component and CK5/6, p63 and p40 in the squamous component, which expression pattern was different from that of PMEC. Based on IHC staining, 2 cases of highly invasive ALK-positive adenocarcinoma mimicing PMEC were also found in the study. Conclusions: MAML2 gene translocation can be detected in about two-third of PMEC. Translocation of MAML2 gene and lower morphology grading are associated with good prognosis. The combined use of IHC antibodies panel is helpful to distinguish PMEC from the adenosqumous carcinoma and adenocarcinoma mimicing PMEC.

Endobronchial tumor in children: Unusual finding in recurrent pneumonia, report of three cases

We are reporting 3 cases of pediatric endobronchial tumors presented with recurrent pneumonia. The median age of patients, at time of presentation, was 10.6 years. All patients presented with recurrent pneumonia with a mean time to occurrence, after onset of symptoms, of 14 mo. Bronchoscopy was early performed as part of diagnostic work-up and it revealed an endobronchial mass in every case. Complete surgical resection was performed in all cases, with lung preservation in two of them. Neither post-operative chemotherapy nor radiotherapy was required. The mean duration of follow-up was 7 years and all patients are still alive and disease-free. Recurrent pneumonia, in pediatrics, should raise the suspicion of an obstructing lesion, congenital malformation or systemic disease. A systematic approach is useful for organize the clinicians initial workup. Prompt diagnosis allows parenchymal-sparing surgery, which offers the best chance of cure and reduces clinical and functional complications in these patients.

Primary mucoepidermoid tumor of the middle ear and mastoid

Mucoepidermoid tumors are salivary gland neoplasms located mainly in the parotid gland. We present an unusual case of such a tumor arising from the middle ear and mastoid cavity successfully treated by surgery and post-operative radiotherapy.