Pulmonary mucinous cystadenocarcinoma presenting as a pleural mesothelioma

Primary Pulmonary Mucinous Cystadenocarcinoma PPMC is an extremely rare subtype of pulmonary adenocarcinoma, with only a few dozen cases reported in the literature to date.

We report a extremely rare case of pulmonary mucinous cystadenocarcinoma presenting as a pleural mesothelioma. 53-year-old man exposed to asbestos, he is admitted in hospital with a 5cm mass in right pleura. He was treated by wedge resection. Sparse groups of malignant cells were microscopically observed in pools of mucin. The postoperative histopathological findings were in accordance with the diagnosis of pulmonary mucinous cystadenocarcinoma on cystic adenoid malformation of lung. 5 years later, the patient has no recurrence.

PPMC is usually asymptomatic; hemoptysis is seen occasionally. Preoperative diagnosis is very difficult to establish. Both FNA cytology and transbronchial lung biopsy seem inadequate. Our patient went on to undergo open lung biopsy and histopathological testing that confirmed the diagnosis of PMC.

It is important to differentiate this rare pathological feature of the lung from other lung tumors as the treatment is surgical rather than medical. Thoracic surgeons should bear in mind this rare tumor for the differential diagnosis of a pleural mesothelioma because this tumor has a favorable prognosis.