An clinicopathological analysis and literature review of pleuropulmonary blastoma in an adult / 重庆医学

ABSTRACT

Objective To explore the clinicopathological features ,diagnosis and differential diagnosis of pleuropulmonary blasto-ma(PPB) .Methods A case of PPB was reported by light microscopic observation ,immunohistochemistry and molecular pathology study with review of related literature .Results A 45-year-old female was admitted to the hospital because of cough and dyspnea . Chest radiogram revealed a solid mass in the left lung .Grossly ,the tumor was described as a firm lesion with lumina or multicystic components and well-circumscribed margins .Microscopically ,the tumor was composed of sheets of malignant primitive small cells and fascicles of embryonal rhabdomyosarcoma-like cells with foci hyalinized stroma .Beneath the benign epithelium ,the primitive mesenchymal cells showed as mixed blastematous and sarcomatous characteristics that plump spindle shaped cells presented poor differention with abundant eosinophilic cytoplasms and brisk mitotic activities .Immunohistochemically ,vimentin and MyoD-1 were positive in malignant small cells but some epithelial markers are negative .Meanwhile ,K-RAS extron 3 mutation was detected by high resolution melting analysis(HRMA) .Conclusion Pleuropulmonary blastoma(PPB) is a rare malignant tumor with unique clinicopathological features .It should be distinguished from some mimics such as pulmonary blastoma and embryonal rhabdomyo-sarcoma .