RESUMEN
A 58-year-old woman presented with an incidental asymptomatic mass occupying the entire right lower thorax. A radiologic study demonstrated a huge cystic mass, initially suggestive of an exophytic echinococcal cyst. After unsuccessful catheter drainage, the patient was referred for surgery, and curative resection of the lung-, heart-, and diaphragm-compressing mass was performed under video-assisted thoracoscopic surgery. Culture studies revealed no growth of parasitic, bacterial, or fungal infections, and the final pathological result confirmed a primary pleural cyst. Thoracic cystic masses mostly manifest as bronchogenic or pericardial cysts, while primary pleural cysts have rarely been reported. We present a rare case of a huge pleural cyst that initially mimicked an echinococcal cyst.
RESUMEN
OBJECTIVES: Peritoneal mesothelial cysts have been reported under various terms, including benign cystic mesothelioma, usually in the form of case reports/series, whereas extraperitoneal cases are rarely reported. Our objective was to report the detailed characteristics of cystic lesions of the serosal cavities. METHODS: We retrospectively examined the clinicopathologic findings of a series of mesothelial cystic lesions (n = 79). RESULTS: Most cases (n = 68, 86%) concerned the peritoneum, whereas 11 (14%) concerned the pericardium. No pleural cases were found. A total of 51 (64.5%) lesions were solitary, whereas 28 (35.5%) were multiple. Peritoneal lesions harbored a plump eosinophilic mesothelium and a loose connective stroma, whereas pericardial lesions showed a cuboidal/flattened mesothelium, collagenous stroma, intense inflammation, and other tissue types, like adipose and muscle tissue. Solitary peritoneal lesions are usually extrapelvic and found in older patients incidentally during other surgeries, whereas multiple lesions are found in younger patients and usually in the pelvis. The lesions show a benign clinical course with rare recurrences but no malignant transformation. CONCLUSIONS: Most mesothelial cysts are peritoneal and rarely pericardial. Peritoneal cysts differ from pericardial cysts. Peritoneal solitary lesions differ from multiple lesions, also suggesting their pathogenetic differences.