Primary alveolar rhabdomyosarcoma of the bone: two cases and review of the literature

Abstract

BackgroundRhabdomyosarcoma (RMS) is a malignant tumor of mesenchymal origin and comprises the largest category of soft-tissue sarcomas both in children and adolescents. From a pediatric oncology point of view, RMS has traditionally been classified into alveolar (ARMS) and embryonal (ERMS) subtypes. The anatomical localization of the tumor may vary, but commonly involve the head/neck regions, male and female urogenital tract or the trunk and extremities.Case presentationHere, we report two challenging cases involving 17- and 9-years-olds males where diffuse and multiplex bone lesions suggested either a hematological disease or a primary bone tumor (mesenchymal chondrosarcoma). Biopsies, proved a massive infiltration of the bone marrow cavity with rhabdomyosarcoma. In both cases, the ARMS subtype was confirmed using FOXO1 break-apart probes (FISH). Radiological examination could not identify primary soft tissue component in any localization at the time of diagnosis in either cases.ConclusionsPrimary alveolar rhabdomyosarcoma of the bone as a subtype of ARMS, seems to be a distinct clinico-pathological entity with challenging diagnostic difficulties and different, yet better, biological behavior in comparison to soft tissue ARMS. However, it is difficult to be characterized or predict its prognosis and long-term survival as only sporadic cases (four) were reported so far.

Intratumoral Translocation Positive Heterogeneity in Pediatric Alveolar Rhabdomyosarcoma Tumors Correlates to Patient Survival Prognosis

“…Despite this information, standard practice in the diagnosis of ARMS in the United States includes the determination of histological phenotype, immunohistochemistry to determine expression levels of muscle specific genes, and occasionally fluorescence in situ hybridization (FISH) to determine translocation status (Morotti et al, 2006). In the latter case the most commonly used FISH probe is the FOXO1 break apart probe (Balogh et al, 2016), which determines whether FOXO1, the common gene in both t(1;13) and t(2;13), is intact or has been "broken apart" as a result of a translocation event. While adequate to determine the presence of a FOXO1-containing genetic alteration, the use of this probe requires subsequent RT-PCR analysis to identify the exact translocation event, with RT-PCR being unable to provide more detail about the potential intratumoral heterogeneity of the translocation.…”

Alveolar rhabdomyosarcoma mimicking acute leukemia in an adolescent with deep venous thrombosis – case presentation

“…Alveolar tumors is the second most common subtype and has a worse prognosis. Is usually found in adolescents and it used to occur in deep musculature of the extremities (1,2,3). The symptomatology usually doesn't exist, unless a nerve is compressed.…”

“…The histopatological examination confirm the diagnosis, and MRI can determinate the site of tumor origin, the extent of local invasion and the metastases. The prognosis is bad and the 5-year survival rate (after chemotherapy, radiotherapy and surgical therapy) is posible over the 80%, but only if doesn't exist metastatic disease at the time of diagnosis (1,7,8).…”

Rabdomiosarcomul alveolar mimând leucemia acută la o adolescentă cu tromboză venoasă profundă – caz clinic

“…Subtipul alveolar, al doilea ca frecvenţă după cel embrionar, prezintă severitatea cea mai mare. Este întâlnit în perioada adolescenţei şi prezintă predilecţie pentru muşchii profunzi ai extremităţilor membrelor (1,2,3). Simptomatologia, de regulă, nu există, cu excepţia cazurilor în care un nerv este comprimat.…”

“…Diagnosticul de certitudine este histologic, iar examinarea RMN ajută la decelarea localizării, limitării şi relaţiei tumorii primare cu structurile din vecinătate. Prognosticul este nefavorabil, iar supravieţuirea la 5 ani (postchimioterapie, radioterapie şi excizie chirurgicală) este posibilă într-un procent de 80%, însă doar dacă în momentul diagnosticării nu există metastaze (1,7,8).…”