Rhabdomyosarcoma of breast resembles acute leukemia：a case report and review of the literature / 肿瘤研究与临床

ABSTRACT

Objective To investigate the clinical pathological characteristics, diagnosis and treatment of breast rhabdomyosarcoma, and to enhance the awareness of malignancy infiltration to bone marrow (BM). Methods The data of one case of Rhabdomyosarcoma of breast were analyzed retrospectively. BM aspirate and biopsy, morphology, immunology, cytogenetics, molecular biology (MICM) in different parts of BM, peripheral blood smear, fine puncture of breast mass, final biopsy of breast mass by Mammotome System and whole body PET-CT were performed. The immunochemistry stain of specimen of breast mass was used. Results The peripheral blood smear of this patient showed immature erythrocytes, leucocytes and classification of unknown cells which were consistent with BM morphology. The results of BM aspirate and biopsy depicted a hypercellular specimen with disseminated unknown cells infiltration. Unknown cells were positive for CD56 and negative for any hematopoietic markers by flow cytometry. The whole body PET-CT showed that uptake of 18F-FDG of bilateral breast and whole BM was increased, whereas the mass of breast was not presented by CT. PET-CT suggested a probable malignant hematologic disease. The enough specimen of breast mass got from Mammotome System showed embryonal rhabdomyosarcoma, and the tumor cells were positive for MyoD1, Vimentin and Desmin. Conclusions It is a challenge for early diagnosis of solid sarcoma with unknown origin which diffusely infiltrating into BM. Negative expression of hematopoietic markers by flow cytometry plays a role on differential diagnosis in this setting, whereas PET-CT only provides a valuable reference. Enough specimen and immunohistochemical staining could provide solid evidences of diagnosis.