Histopathological classification of childhood rhabdomyosarcomas: Relationship with clinical parameters and prognosis

Pathologic Classification of Rhabdomyosarcomas and Correlations with Molecular Studies

“…Alveolar and pleomorphic tumors retained the conventional definitions of Horn and Enterline, and a new category, embryonal sarcoma (Fig. 7), arose; these sarcomas were characterized by their low-power similarity to embryonal rhabdomyosarcomas but high-power lack of obvious myogenesis by routine staining (28). Redefinition of embryonal sarcomas becomes necessary when one adds muscle immunostains to the diagnostic armamentarium, as they are usually positive in these tumors, and chemotherapy also induces the tumor cells to exhibit myogenic differentiation (28).…”

“…7), arose; these sarcomas were characterized by their low-power similarity to embryonal rhabdomyosarcomas but high-power lack of obvious myogenesis by routine staining (28). Redefinition of embryonal sarcomas becomes necessary when one adds muscle immunostains to the diagnostic armamentarium, as they are usually positive in these tumors, and chemotherapy also induces the tumor cells to exhibit myogenic differentiation (28). As a result, embryonal sarcomas are considered a primitive form of embryonal rhabdomyosarcoma in our current classification (9).…”

“…One may thus assume that a proportion of the poorly differentiated embryonal rhabdomyosarcomas in the SIOP classification might correspond to solid alveolar rhabdomyosarcomas of the National Cancer Institute (NCI) classification, as described below. Of interest is that the primitive embryonal sarcomas fared better than standard embryonal rhabdomyosarcomas in a subsequent SIOP review (28).…”

Primary Rhabdomyosarcoma of the Breast in a 13-Year-Old Girl: Report of a Case

“…2 There are two histological types of rhabdomyosarcoma: the embryonal type, or its subtypes (60%); and the alveolar type (20%). 3 The prognosis of embryonal rhabdomyosarcoma, which often develops in the head and neck region and urogenital organs in children younger than 10 years old, tends to be favorable, whereas the that of the alveolar type, which often develops in the extremities in children over 10 years old, tends to be poor, with poor responses to chemotherapy and the likelihood of early metastasis. 4 The Intergroup Rhabdomyosarcoma Study Group (IRS) of the United States conducted five clinical trials on this tumor after 1972, and obtained more useful results than any previous studies.…”

Primary alveolar rhabdomyosarcoma of breast in a 13 year old female with cardiopulmonary metastases and cyto-histological correlation: A case report

“…In childhood, there are three important histological types: the embryonal type (60%) and the alveolar (20%) [5]. The embryonal rhabdomyosarcoma predominantly seen in age group 0-4 commonly affects the genital urinary system and head and neck tends to have a better prognosis compared to the alveolar type which often develop in the extremities in children over 10 years , resistant to chemotherapy and metastasis early [6].…”