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Solid alveolar rhabdomyosarcoma of the thorax in a child
Author(s) -
Hervé Sartelet,
Sylvie Lantuéjoul,
C Armari-Alla,
I. Pin,
Olivier Delattre,
Élisabeth Brambilla
Publication year - 1998
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1046/j.1365-2559.1998.00351.x
Subject(s) - alveolar rhabdomyosarcoma , rhabdomyosarcoma , pathology , desmin , vimentin , immunohistochemistry , sarcoma , neural cell adhesion molecule , mediastinum , metastasis , embryonal rhabdomyosarcoma , biology , medicine , anatomy , cell , cell adhesion , cancer , genetics
Aims: This case illustrates the difficulties and pitfalls of diagnosis of alveolar rhabdomyosarcoma in its solid variant and in an unusual primary location, the mediastinum. Case details: A 9‐year‐old boy presented with a primary thoracic tumour associated with metastasis in the left sacroiliac joint. Bronchial and mediastinal biopsies showed a malignant neoplasm with a solid sheet‐like pattern of small round cells with a high nuclear to cytoplasmic ratio associated with little or no fibrosis usually evocative of a peripheral neuroectodermal tumour (PNET) at this age. Immunohistochemical positive staining with vimentin (80% of tumour cells), desmin (20%) and titin (30%) antibodies was suggestive of a rhabdomyosarcoma. In addition, all neural cell adhesion molecule (NCAM) markers tested were positive as well as MIC2, a marker for the Ewing family of sarcomas. There was no rhabdomyoid differentiation at ultrastructural examination. Molecular analysis with RT‐PCR amplification of RNA isolated from the tumour demonstrated the presence of a PAX3/FKHR fusion transcript, product of a t(2;13) reciprocal translocation, a genetic marker specific for alveolar rhabdomyosarcoma. Conclusion: The diagnostic methodology of a small round cell tumour of the child must now include immunohistochemical study and molecular biology to confirm the diagnosis of alveolar rhabdomyosarcoma, in a solid and undifferentiated variant.