gms | German Medical Science

Introduction: Abundant extra cellular mucin secretion by cystic neoplasm is seen in organs like ovary, breast and pancreas. Pulmonary mucinous cystadenocarcinoma (PMCC) are extremely rare. Until 2005, 76 cases have been reported in the English literature. We present a case of a 40-year-old man submitted to our hospital.

Case report: The young man went to his family doctor with nightly sweating, loss of capacity and knee pain. A chest X-ray was done to rule out Wegner Granulomatosis but the chest X-ray revealed a solitary mass at the periphery of the right middle lobe of the lung. A computed tomographic scan bared an isolated middle lobe mass, 1.5 cm in diameter with no lymph nodes. A thorascopic wedge-resection was done under the diagnosis of brochogenic cyst. Intraoperative frozen section showed the tumor to be a mucinous cystadenocarcinoma resected with clear margin. The surgical procedure was well tolerated and the patient was discharged after 5 days without any complications. Histologically, columnar mucinous cells and cystic spaces were observed. The epithelial lining showed severe nuclear atypia with mucin depletion in some areas, but the all over degree of cytologic atypia was highly variable.

Comment: The PMCC is a very rare disease. According to the cases reported in the literature, patients age range from 32 to 81 years. There are no typical clinical features. The definitive diagnosis can only be made by histological examination. From the pathological point of view it is important to distinguish it from other primary mucinous lesions of the lung and metastasis of mucinous tumors from other sites. But in our patient the definitive histology showed a mucinous cystadenocarcinoma. Taking in account the literature, there are no clear strategies for the surgical procedure. Half of the patients received local wedge resection in small tumors and other received lobectomy. According to WHO tumors smaller than 5 cm and with clear margin do not need any further therapy after wedge resection. In the publication of Rossi et al. the immunhistochemical expression of MUC5 and the negative results for CDX2 and MUC2 are associated with a dismal prognosis. Beside the tumor diameter and immunhistochemical findings signet-ring cells type tumors seems to have higher potential to metasize. In our case, the diameter is 1.5 cm and it is a goblet cell type tumor. Immunhistochemically the tumor is negative for the expression of MUC5 and positive for CDX2 and MUC2. Therefore, we decided local wedge resection should be the right surgical procedure accompanied by close follow-up. This follow-up should include a CT scan of the brain, the chest and bone scan, because the published cases showed local recurrence or metastasis in the bone or brain. But this recommendation needs further evaluation.