Rapidly progressive congenital rhabdomyosarcoma presenting with multiple cutaneous lesions: an uncommon diagnosis and a therapeutic challenge.

Congenital rhabdomyosarcomas (RMSs) are rare tumors with variable clinical presentations. A 2 month-old, term male neonate (37 weeks, 4 days), weighing 3.2kg, born to a 24 year-old primigravida, by simple vaginal delivery presented with multiple erythematous papulonodular lesions over his trunk that progressed to his whole body, on the first day of delivery. Prior to conception, his mother was treated for polycystic ovarian disease. On the tenth day, his chest computed tomogram scans revealed multiple, heterogeneously enhancing, bilateral pleural-based soft tissue density nodular lesions, along with multiple soft tissue density lesions, involving skeletal muscles of all his body parts. Microsections from two biopsies (on 10th day and after 2 months) revealed a malignant round cell tumor with cells arranged in a diffuse, solid pattern, comprising embryonal and solid alveolar components. Immunohistochemically, the tumor cells were diffusely positive for desmin, myoD1 and myogenin. Diagnosis of embryonal and alveolar (mixed type) RMS was offered. Further molecular cytogenetic analysis was negative for PAX3-FKHR and PAX7-FKHR. The patient was induced on chemotherapy as per intergroup rhabdomyosarcoma study IV protocol. There was treatment response with near total remission after 8 weeks of treatment. Thereafter, new lesions started appearing that also disappeared after modification of the chemotherapy drugs. However, after 16 months, the baby died of brain metastasis. The present case forms the fourth case report of an aggressive form of a congenital RMS with extensive cutaneous involvement and brain metastasis. A review of previously diagnosed cases of congenital RMSs is discussed herewith.