Disseminated alveolar rhabdomyosarcoma in a child with spinal muscular atrophy

Epithelioid neoplasm of the spinal cord in a child with spinal muscular atrophy treated with onasemnogene abeparvovec

Spinal muscular atrophy is an autosomal recessive disease resulting in motor neuron degeneration and progressive life-limiting motor deficits when untreated. Onasemnogene abeparvovec is an adeno-associated virus serotype 9-based gene therapy that improves survival, motor function, and motor milestone achievement in symptomatic and presymptomatic patients. Although the adeno-associated virus genome is maintained as an episome, theoretical risk of tumorigenicity persists should genomic insertion occur. We present the case of a 16-month-old male with spinal muscular atrophy who was diagnosed with an epithelioid neoplasm of the spinal cord approximately 14 months after receiving onasemnogene abeparvovec. In situ hybridization analysis detected an onasemnogene abeparvovec nucleic acid signal broadly distributed in many but not all tumor cells. Integration site analysis on patient formalin-fixed, paraffin-embedded tumor samples failed to detect high-confidence integration sites of onasemnogene abeparvovec. The finding was considered inconclusive because of limited remaining tissue/DNA input. The improved life expectancy resulting from innovative spinal muscular atrophy therapies, including onasemnogene abeparvovec, has created an opportunity to analyze the long-term adverse events and durability of these therapies as well as identify potential disease associations that were previously unrecognized because of the premature death of these patients.

Spinal Muscular Atrophy and Ependymoma

Spinal muscular atrophy (SMA) is an autosomal recessive disorder, characterized by a progressive degeneration of anterior horn cells of the spinal cord resulting in hypotonia, skeletal muscle atrophy and weakness. We report the case of a 33-year-old female with SMA type IV (SMA4) who presented with symptoms of spinal cord lesion that was initially missed. Further evaluation resulted in the diagnosis of ependymoma. To the best of our knowledge, this is the first time that the coexistence of SMA4 and ependymoma has been reported.

Neuroblastoma in a Patient With Spinal Muscular Atrophy Type I: Is It Just a Coincidence?

Spinal muscular atrophy is an autosomal recessive disorder characterized by progressive degeneration of anterior horn cells of the spinal cord resulting in hypotonia, skeletal muscle atrophy, and weakness. Herein, we report a 4-month-old male infant who presented to our hospital with an abdominal mass that was diagnosed as neuroblastoma and spinal muscular atrophy type I. We would like to discuss the course and differential diagnosis with an algorithm leading to the diagnosis in this peculiar patient. To our knowledge, coexistence of spinal muscular atrophy type I and neuroblastoma is defined for the first time in the literature.

Alveolar rhabdomyosarcoma in infantile spinal muscular atrophy: coincidence or predisposition?

We report two unrelated patients with infantile spinal muscular atrophy (SMA) types II and IIIa who developed alveolar rhabdomyosarcoma (ARMS) at 15 and 19 years, respectively. The tumours were located in the forearm, within severely atrophic flexor muscles. They displayed a similar histology and shared the most common translocation, t(2;13)(q35;14) in ARMS. Since cell proliferation is increased in de- and regenerating muscle and the PAX3/FKHR fusion protein activates myogenic transcription, it is tempting to speculate whether severe muscle atrophy in SMA might predispose to malignant transformation in long-standing disease.