sclerosing rhabdomyosarcoma

Definition: Sclerosing rhabdomyosarcoma, a particular phenotypic variant of rhabdomyosarcoma initially described in the adult population, has emerged as a potential pitfall in the evaluation of pediatric sarcomas.

Sclerosing rhabdomyosarcoma (RMS) is characterized by a hyalinizing, matrix-rich stroma. It is a newly described variant of rhabdomyosarcoma with a predilection for the head and neck.

Synopsis

 prominent sclerosing hyaline matrix
 pseudovascular and microalveolar architectural foci
 focal positivity for desmin, smooth muscle actin, and myogenin.

Ultrastructure

 irregularly distributed disorganized filaments without clear evidence of Z-bands
 richly collagenized matrix

Differential diagnosis

Because of its densely hyalinized collagenous matrix and its occasional expression of a pseudovascular pattern of growth, sclerosing rhabdomyosarcoma has been at times misdiagnosed as chondrosarcoma, osteosarcoma, or angiosarcoma. (#12218574#)

Comparative genomic hybridization

 loss of chromosomal region 10q22 (#17016719#)
 loss of chromosome Y (#17016719#)
 gain of chromosome 18 (trisomy) (#17016719#)

Cytogenetics

 mild hyperdiploidy (#15630526#)
 near-tetraploidy (#15630526#)

 del(1)(p22) (#15660283#)
 trisomy 11 (+11) (#15660283#)
 trisomy 16 (+16) (#15660283#)
 tumoral trisomy 18 (+18) (#15660283#)
 tumoral trisomy 21 (+21) (#15660283#)
 monosomy 22 (-22) (#15660283#)

CGH

 10q22 loss (#17016719#)
 Chr.Y loss (#17016719#)
 Chr.18 gain (trisomy 18) (#17016719#)

See also

 rhabdomyosarcomas

References

 Kuhnen C, Herter P, Leuschner I, Mentzel T, Druecke D, Jaworska M, Johnen G. Sclerosing pseudovascular rhabdomyosarcoma-immunohistochemical, ultrastructural, and genetic findings indicating a distinct subtype of rhabdomyosarcoma. Virchows Arch. 2006 Nov;449(5):572-8. PMID: #17016719#

 Zambrano E, Perez-Atayde AR, Ahrens W, Reyes-Mugica M. Pediatric sclerosing rhabdomyosarcoma. Int J Surg Pathol. 2006 Jul;14(3):193-9. PMID: #16959698#

 Croes R, Debiec-Rychter M, Cokelaere K, De Vos R, Hagemeijer A, Sciot R. Adult sclerosing rhabdomyosarcoma: cytogenetic link with embryonal rhabdomyosarcoma. Virchows Arch. 2005 Jan;446(1):64-7. PMID: #15660283#

 Knipe TA, Chandra RK, Bugg MF. Sclerosing rhabdomyosarcoma: a rare variant with predilection for the head and neck. Laryngoscope. 2005 Jan;115(1):48-50. PMID: #15630365#

 Vadgama B, Sebire NJ, Malone M, Ramsay AD. Sclerosing rhabdomyosarcoma in childhood: case report and review of the literature. Pediatr Dev Pathol. 2004 Jul-Aug;7(4):391-6. PMID: #15383934#

 Chiles MC, Parham DM, Qualman SJ, Teot LA, Bridge JA, Ullrich F, Barr FG, Meyer WH; Soft Tissue Sarcoma Committee of the Children’s Oncology Group. Sclerosing rhabdomyosarcomas in children and adolescents: a clinicopathologic review of 13 cases from the Intergroup Rhabdomyosarcoma Study Group and Children’s Oncology Group.
Pediatr Dev Pathol. 2004 Nov-Dec;7(6):583-94. PMID: #15630526#

 Vadgama B, Sebire NJ, Malone M, Ramsay AD. Sclerosing rhabdomyosarcoma in childhood: case report and review of the literature. Pediatr Dev Pathol. 2004 Jul-Aug;7(4):391-6. PMID: #15383934#

 Sclerosing rhabdomyosarcoma in adults: report of four cases of a hyalinizing, matrix-rich variant of rhabdomyosarcoma that may be confused with osteosarcoma, chondrosarcoma, or angiosarcoma. Folpe AL, McKenney JK, Bridge JA, Weiss SW. Am J Surg Pathol. 2002 Sep;26(9):1175-83. PMID: #12218574#

 Mentzel T, Katenkamp D. Sclerosing, pseudovascular rhabdomyosarcoma in adults. Clinicopathological and immunohistochemical analysis of three cases. Virchows Arch. 2000 Apr;436(4):305-11. PMID: #10834531#