* <spoiler text="What is your The radiologic differential diagnosis?">These groups of cells demonstrate malignant appearing cells in a background of an otherwise benign appearing lymphoid background. The atypical cells are scattered, with large nucleoli was between osteosarcoma and several binucleate forms. In addition, there seem to be an increased number of eosinophils in the background. The differential diagnosis includes Hodgkin lymphoma; however, the possibility of the large atypical cells being melanoma cannot be ruled outEwing sarcma. </spoiler>* <spoiler text="What ancillary tests would you recommend?">For this patient, we recommended that the radiologist perform a biopsy of the lesion so that it could be sent for immunohistochemical workup. Since the overall percentage of the atypical cells were low, we were worried that a cell block would not contain enough of the malignant cells for additional stains. We also sent the lymph node for flow since a hematologic malignancy was suspected; however, with Hodgkin lymphoma, we don't expect any possible diagnostic findings from flow cytometry.</spoiler>* <spoiler text="What immunohistochemical stains would you dopitfall?">CD15, CD30, The confusion between osteosarcoma and PAX5 would stain tumor cells in Hodkin lymphoma. Mart1, HMB45, and S100 could be used to rule out melanoma. Other additional stain in a lymphoma versus melanoma workup might include CD3, CD20, and keratinEwing may occur with the small cell variant of osteosarcoma. </spoiler>

CytologicallyYoursCoW20131202Biopsy1.jpg|20x magnification of lymph node core bone biopsy.CytologicallyYoursCoW20131202Biopsy2.jpg|40x magnification of lymph node core biopsy. CytologicallyYoursCoW20131202Biopsy3.jpg|CD 15 with membranous staining.CytologicallyYoursCoW20131202Biopsy4.jpg|CD 30 with membranous staining. showing sclerotic bone

* '''Classical Hodgkin lymphomaConventional high grade sarcoma, favor mixed sclerotic type'''.** CD15 Positive in tumor cells** CD30 Positive in tumor cells** PAX5 Weakly positive** CD20 Positive in background lymphocytes** CD3 Positive in background lymphocytes** S100 Negative** Mart1 Negative** HMB45 Negative

The features experience of Hodgkin lymphoma include atypical (Hodgkin cells) FNA of osteosarcoma is mainly with conventional high-grade intramedullary sarcoma and Reedto the rare high-Sternberg cellsgrade surface osteosarcoma. The nucleus should be 3-4x the size of a small lymphocyte. In classic Hodgkin lymphoma, scattered eosinophils, plasma Smears usually contain dissociated neoplastic cells, histiocytes, and a predominately CD3+ lymphocyte population will be seen in the background. The immunophenotype of classic Hodgkin lymphoma shows CD15, CD30, MUM1, and weak PAX5 positivity. Histology is usually needed to subtype Hodgkin lymphomacell clusters.