Clinical, morphological, and immunohistochemical analysis of head and neck rhabdomyosarcomas in pediatric patients

Abstract

Objective To analyze the clinicopathologic and immunohistochemical features of head and neck rhabdomyosarcomas (HNRMS) in pediatric patients from Brazil, Guatemala, Mexico, and South Africa. Study Design Thirty-eight pediatric HNRMS were obtained from six Oral Pathology services in 23 years. Clinicopathological and immunohistochemical data of all cases were reviewed. Results Most patients were from Brazil and South Africa (12/38; 31.6%, each), ten (26.3%) were from Guatemala, and four (10.5%) were from Mexico. The mean age of patients was 7.6 ± 4.7 years (range 1-19 years) with a slight female predilection. Non-parameningeal tissues (47.4%) were most commonly affected, followed by parameningeal (36.8%) and orbit (13.2%). Microscopically, the most common subtype was embryonal 86.8% (33/38), followed by alveolar 13.2% (5/38). Almost all cases (92.1%; 35/38) were positive for at least two myogenic markers: Desmin, Myogenin, and Myo-D1. Moderate to high Ki-67 proliferation index was identified in most cases. Conclusion Pediatric HNRMS from Brazil, Guatemala, Mexico, and South Africa are more frequently diagnosed in children <10 years old and present classic clinicopathologic and immunohistochemical features for each subtype. To analyze the clinicopathologic and immunohistochemical features of head and neck rhabdomyosarcomas (HNRMS) in pediatric patients from Brazil, Guatemala, Mexico, and South Africa. Thirty-eight pediatric HNRMS were obtained from six Oral Pathology services in 23 years. Clinicopathological and immunohistochemical data of all cases were reviewed. Most patients were from Brazil and South Africa (12/38; 31.6%, each), ten (26.3%) were from Guatemala, and four (10.5%) were from Mexico. The mean age of patients was 7.6 ± 4.7 years (range 1-19 years) with a slight female predilection. Non-parameningeal tissues (47.4%) were most commonly affected, followed by parameningeal (36.8%) and orbit (13.2%). Microscopically, the most common subtype was embryonal 86.8% (33/38), followed by alveolar 13.2% (5/38). Almost all cases (92.1%; 35/38) were positive for at least two myogenic markers: Desmin, Myogenin, and Myo-D1. Moderate to high Ki-67 proliferation index was identified in most cases. Pediatric HNRMS from Brazil, Guatemala, Mexico, and South Africa are more frequently diagnosed in children <10 years old and present classic clinicopathologic and immunohistochemical features for each subtype.