Congenital alveolar rhabdomyosarcoma with multiple skin metastases. Report of a case

Congenital Rhabdomyosarcoma: a different clinical presentation in two cases

BACKGROUND

Rhabdomyosarcoma (RMS), one of the most common soft tissue sarcomas of childhood, is very rare in the neonatal period (0.4-2% of cases). In order to gain a deeper understanding of this disease at such age, patient and tumor features, as well as treatment modality and outcome need to be reported.

CASE PRESENTATION

We describe two cases with congenital RMS treated at Bambino Gesù Children's Hospital between 2000 and 2016. They represent only 2.24% of all RMS patients diagnosed during that period in our Institution; this data is in agreement with the incidence reported in the literature. They reflect the two different clinical forms in which the disease may manifest itself. One patient, with the alveolar subtype (positive for specific PAX3-FOXO1 fusion transcript) and disseminated disease, had a fatal outcome with central nervous system (CNS) progression despite conventional and high dose chemotherapy. The other child, with the localized embryonal subtype, was treated successfully with conservative surgery and conventional chemotherapy, including prolonged maintenance therapy. He is disease free at 7 years of follow-up.

CONCLUSIONS

RMS can also be diagnosed during the neonatal period. Given the young age, disease management is often challenging, and especially for the alveolar subtype, the outcome is dismal despite intensified multimodality therapy. In fact, it characteristically manifests with multiple subcutaneous nodules and progression most commonly occurs in the CNS (Rodriguez-Galindo et al., Cancer 92(6):1613-20, 2001). In this context, CNS prophylaxis could play a role in preventing leptomeningeal dissemination, and molecular studies can allow a deeper tumor characterization, treatment stratification and identification of new potential therapeutic targets.

Decreased CDKN1C Expression in Congenital Alveolar Rhabdomyosarcoma Associated with Beckwith-Wiedemann Syndrome

The Beckwith-Wiedemann syndrome (BWS) is a genetic disorder characterized by somatic overgrowth and predisposition to embryonal tumors, such as Wilm's tumor, hepatoblastoma, neuroblastoma and rhabdomyosarcoma (RMS). BWS is associated with various genetic alterations: a variety of molecular lesions are described on the chromosome 11p15, affecting gene expression for IGF2, H19, CDKN1C and KCNQ1OT1. Alveolar RMS also recognises characteristic genetic alterations: two types of translocations, t(2,13) or t(1,13), that generate the PAX3-FKHR or PAX7-FKHR fusion proteins. It has been postulated however, that in BWS this kind of tumor occurs without this characteristic chromosomal rearrangement. The authors describe case of a neonate with BWS that presented at birth with cutaneous metastasis due to alveolar RMS. Genetic analysis showed lack of the two characteristic translocations in the tumor tissue, supporting a different oncogenic pathway of alveolar RMS in children with BWS.

Orbital rhabdomyosarcoma with skin metastasis: a case report

Background

Rhabdomyosarcoma is a soft tissue neoplasm that usually arises in the headand neck region and genitourinary tract. Skin metastasis of rhabdomyosarcoma is extremely rare; of thirteen cases reported in the literature, most were children younger than 10 years and only three cases have been reported in adults.

Case presentation

A 20-year-old Moroccan man was admitted with a right orbital tumor. The tumor was excised and histopathology examination confirmed a diagnosis of rhabdomyosarcoma. The patient was treated with chemotherapy, but local recurrence occurred one year later. The patient underwent right orbital exenteration followed by chemotherapy and radiotherapy. After 6 months, the patient developed a cutaneous mass in the right lumbar region, which was resected. Immunohistochemical examination of the tumor showed this to be a cutaneous metastasis of rhabdomyosarcoma. The patient was treated by chemotherapy and there appeared to be no recurrence after 9 months of follow up.

Conclusions

Skin metastasis from rhabdomyosarcoma is extremely rare, particularly in adults. The purpose of presenting this case report is to raise awareness among clinicians— skin biopsy and immunohistochemistry are needed to distinguish this neoplasm from other cutaneous tumors so that appropriate treatment can be initiated.