Rhabdomyosarcomatous differentiation in a neuroblastoma: A potential pitfall in the cytologic diagnosis of small round‐cell tumors of childhood

Abstract

Rhabdomyoblasts demonstrating immunoreactivity for muscle-specific actin, desmin, and myoglobin were identified in smears obtained by aspiration from a large retroperitoneal mass in a 14-mo-old girl. Following a tentative diagnosis of a rhabdomyogenous neoplasm, retroperitoneal exploration and adrenalectomy demonstrated a stromal poor neuroblastoma with extensive rhabdomyogenous differentiation. The presence of a subpopulation of rhabdomyoblasts was not diagnostic of rhabdomyosarcoma when obtained by fine-needle aspiration from a retroperitoneal tumor composed predominantly of primitive small round cells.

Rhabdomyosarcoma in a child with massive pleural effusion: Cytological diagnosis from pleural fluid

“…The amount of sarcoma present in one case was thought to be associated with poorer prognosis and supports quantifying relative proportions of cell populations. 14 Layfield and Glasgow 15 reported on a case of rhabdomyosarcomatous differentiation in a neuroblastoma, highlighting it as a potential pitfall in the cytologic diagnosis of small round-cell tumors of childhood.…”

Fine Needle Aspiration Biopsy of a Small Round Cell Tumor Exhibiting Both Neural and Myogenic Differentiation

“…In a previously reported FNAB of a retroperitoneal SRCT, positive immunocytochemical staining for desmin, MSA and myoglobin led to a diagnosis of rhabdomyosarcoma; subsequent surgery disclosed an adrenal neuroblastoma with rhabdomyosarcomatous differentiation. 8 In our case, adjuvant techniques indicated both neural differentiation (on the basis of ultrastructural features and NSE positivity) and myogenic differentiation (on the basis of MSA and desmin positivity). Ultrastructural examination of FNAB and tissue biopsy material did not show evidence of myofilaments or Z bands.…”

Difficulties in diagnosing small round cell tumours of childhood from fine needle aspiration cytology samples

“…RMS is the most common heterologous component of various malignant tumours. It has been described in germ cell tumours, 9 in neuroblastoma 10 and in pleuropulmonary blastoma 11 . We have aspirated a nephroblastoma that was only a component of a germ cell tumour.…”