Neuro / Head & Neck for Wednesday, April 9th, 2025

Contributed by Vanderbilt University Medical Center
Hae Weon Lee, and Sudha P. Singh, M.B.B.S., M.D..

History

35 month old female with no significant medical history who presents to the Emergency Department with worsening gait disturbance and tremor. CT and MRI of head done at initial presentation 1 month prior was negative.

Images (Click any image to enlarge)

Question

What is the diagnosis?

Your answer

Please log in to see your results.

Correct answer

Neuroblastoma presenting with paraneoplastic syndrome (OMAS)

Discussion

In a 35 month old patient presenting with opsoclonus-myoclonus-ataxia syndrome (OMAS) and a 6 cm left retroperitoneal mass, neuroblastoma would be the favored diagnosis. Neuroblastoma, which accounts for 97% of all neuroblastic tumors, is the most common solid tumor in children under the age of 5.

This patient with low risk neuroblastoma underwent surgical resection with pathological confirmation of a neuroblastoma, and her OMAS was treated with IVIg, dexamethasone, and rituximab. The patient still had residual motor symptoms at the end of therapy.

2 to 3% of patients diagnosed with neuroblastoma present with OMAS. In contrast, 50% of children presenting with OMAS have an underlying neuroblastoma. While the exact etiology of OMAS is unclear, it is thought to be caused by the immune system reacting to a tumor (most commonly neuroblastoma) and producing antibodies to the cerebellum. This response causes the clinical manifestation of gait imbalance, staggering, or falls. Other symptoms of OMAS include myoclonus of the limbs and trunk, hypotonia, and opsoclonus.

Initial treatment of OMAS in the setting of neuroblastoma is immunosuppression via glucocorticoids and intravenous immunoglobulin (IVIg). If there is insufficient response to this therapy, rituximab or cyclophosphamide can be added. Focus is on early and aggressive treatment for best outcomes.

Despite the favorable oncologic prognosis of neuroblastomas, 60-80% of patients with OMAS have residual behavioral abnormalities or psychomotor slowing at the end of therapy.

Differential diagnosis

  • Wilms' tumor
  • Lymphoma
  • Teratoma
  • Lipoblastoma
  • Rhabdomyosarcoma

References

  • Dalmau J, Rosenfeld MR. Opsoclonus-myoclonus-ataxia syndrome. In: UpToDate, Connor RF (Ed), Wolters Kluwer. (Accessed on March 8, 2025.)
  • Shohet JS, Nuchtern JG, Foster JH. Clinical presentation, diagnosis, and staging evaluation of neuroblastoma. In: UpToDate, Connor RF (Ed), Wolters Kluwer. (Accessed on March 8, 2025.)
  • Shohet JS, Nuchtern JG, Foster JH. Treatment and prognosis of neuroblastoma. In: UpToDate, Connor RF (Ed), Wolters Kluwer. (Accessed on March 8, 2025.)