Pulmonary sclerosing pneumocytoma presenting as slow-growing multiple nodules over a long period

Pulmonary sclerosing pneumocytoma is an uncommon slow-growing benign tumor that usually occurs in middle-aged women and generally presents as a solitary well-defined nodule. An 18-year-old woman was incidentally detected to have multiple lung nodules on chest radiography that slowly increased in size over a period of 7 years. Computed tomography images showed multiple well-defined nodules surrounded by numerous smaller nodules with a maximum diameter of 3 cm in the left lung. A percutaneous core needle biopsy was performed, but malignancy could not be excluded because of the high proportion of papillary structures. A video-assisted partial wedge resection was performed and the pathologic diagnosis was pulmonary sclerosing pneumocytoma. Pulmonary sclerosing pneumocytoma presenting as multiple lung nodules is a rare but very important condition to include in the differential diagnosis of multiple lung nodules. There is a possibility of misdiagnosis of another type of tumor or malignancy on preoperative biopsy. We should be aware not only of the clinical, radiologic, and pathologic features of pulmonary sclerosing pneumocytoma but also of the potential pitfalls in its diagnosis and management. Keywords: Pulmonary sclerosing pneumocytoma, Pulmonary sclerosing hemangioma, Multiple nodules, Biops

A case of pseudocystic liver metastases from an atypical lung carcinoid tumor

Metastatic neuroendocrine tumors of the liver typically appear as solid, hypervascular masses on imaging. Pseudocysts mimicking simple cysts are extremely rare. A 42-year-old Japanese woman was referred with a single pulmonary mass in the left lower lobe. No metastatic lesion was detected and no occupying lesion in the liver was observed. The lung tumor was diagnosed as an atypical carcinoid. Postoperative investigation revealed new hepatic simple cysts in the liver, which increased in size over time and changed into hemorrhagic cysts. Fluorodeoxyglucose positron emission tomography and somatostatin receptor scintigraphy using 111In-octreotide demonstrated no accumulation in the liver. Our patient did not have symptoms consistent with carcinoid syndrome. The patient underwent partial resection of the cystic lesions of the liver. Gross examination of the tumors demonstrated thin-wall cavitated lesions with hemorrhage which were metastases from the atypical carcinoid of the lung. When a growing cystic lesion with intracystic hemorrhage is found in the liver of a patient with a history of carcinoid tumors, pseudocysts caused by degeneration of a carcinoid metastasis should be considered as a differential diagnosis. Keywords: Lung carcinoid tumor, Neuroendocrine tumor, Carcinoid metastasis, Liver metastasis, Pseudocys