Mixed embryonal/alveolar rhabdomyosarcoma of the prostate: report of a case with molecular genetic studies and literature review.
ABSTRACT Alveolar rhabdomyosarcoma (RMS) is 1 of 2 main subtypes of RMS in the pediatric age group and tends to occur in the extremities. The urogenital tract is another common site for RMS, but this typically involves the embryonal subtype including sarcoma botryoides. We report a 28-year-old male with a prostatic tumor that was excised en bloc and showed a RMS with separate areas of embryonal and solid alveolar morphologies at the light microscopic level. Both areas showed diffuse nuclear expression for myogenin, and both areas expressed the PAX3-FKHR fusion gene, a genetic change associated with alveolar but not embryonal RMS. A review of the literature documented only 5 cases of RMS primary to the prostate showing alveolar or mixed histology. Ours is the 6th case and the 1st with molecular findings. Although the diagnostic category of mixed embryonal/alveolar RMS remains in use, the nature of this type of RMS is incompletely understood. In our case, although the morphology was mixed embryonal/alveolar, at the genetic level this tumor was alveolar in nature.
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ABSTRACT: The International Classification of Rhabdomyosarcoma (ICR) has provided diagnostic criteria for rhabdomyosarcoma (RMS) and formed the basis of histologic risk stratification since its publication in 1995. However, the recognition of new variants of embryonal rhabdomyosarcoma (ERMS), shifts in the diagnostic criteria of alveolar rhabdomyosarcoma (ARMS), the increasing use of myogenin immunohistochemistry and recognition of the distinct biologic properties associated with fusion status all raised questions about the continued use of this classification system in the diagnosis and treatment of patients with RMS. Recent Children's Oncology Group Soft Tissue Sarcoma Committee analysis of histology and fusion status in the intermediate risk RMS study D9803 refined the histologic criteria of RMS. We validated the new diagnostic criteria against fusion status, allowing prospective examination of the prognostic value of histology compared with fusion status for risk-stratification of patients with RMS. This article summarizes the evolution of and current practices in the histologic and molecular classification of rhabdomyosarcoma.American Society of Clinical Oncology educational book / ASCO. American Society of Clinical Oncology. Meeting. 01/2013; 2013:425-428.
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ABSTRACT: Alveolar rhabdomyosarcoma (ARMS) is a subtype of rhabdomyosarcoma and usually occurs in childhood and adolescence. ARMS is characterized by its aggressive behavior and poor prognosis. To improve the unfavorable prognosis, new therapeutic developments and the establishment of methods for precise prognostic prediction are required. We describe a case of ARMS, solid variant, which occurred in a 10-year-old boy. After chemotherapy and radiotherapy, the tumor morphologically and immunohistochemically showed marked cytodifferentiation, whereas the exact same PAX3-FKHR chimeric fusion gene transcript was detected in samples before and after treatment. The result of this study seems to indicate that therapeutic cytodifferentiation does not always correlate with genetic change and favorable prognosis in ARMS.Human Cell 12/2013; 26(4):149-54. · 1.74 Impact Factor
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ABSTRACT: Both benign and malignant pelvic masses are encountered in the pediatric population. Although ultrasonography remains the modality of choice for initial evaluation of a pediatric pelvic mass, in selected cases magnetic resonance (MR) imaging can add important diagnostic information. MR imaging has several advantages over ultrasonography and computed tomography, including superior contrast resolution and an ability to characterize abnormalities based on unique tissue characteristics. MR evaluation assists in lesion characterization, presurgical planning, and staging when a malignancy is suspected. MR imaging also offers a nonionizing imaging modality for long-term follow-up of patients undergoing therapy for malignant pelvic masses.Magnetic resonance imaging clinics of North America 11/2013; 21(4):751-72.