Primary pulmonary spindle cell rhabdomyosarcoma in adolescent: a case report and review of literatures

Spindle cell rhabdomyosarcoma (SRMS) is a rare and new type of rhabdomyosarcoma. SRMS in lung is extremely rarely. Here we report on a first explicit case of SRMS in lungs of a 13-year-old girl. Macroscopic examination showed a tumor (65 mm×17 mm×9 mm) with a solid gray-white cut surface which displays invasive growth but was well-circumscribed. Histologically, tumor cells were formed with spindle to round cells with eosinophilic cytoplasm and fascicular, storiform, wavy appearance. Horizontal grain structure and striated muscle brood cells were observed in some cells or local regions. A small amount of collagen fibers were observed in the mesenchyme. The nucleus was long or wavy with nuclear heteromorphosis. Immunohistochemically, tumor cells were stained diffusely positive for muscle specific actin, desmin, and vimentin, scattered positive for myogenin, MyoD1 and myoglobin. According to the examination results, this case was diagnosed as SRMS. Then the tumor was completely excised with a part of lung tissues, and additional chemotherapy was given.