Clinical responses to rituximab in a case of neuroblastoma with refractory opsoclonus myoclonus ataxia syndrome

Review of Paraneoplastic Syndromes in Children with Malignancy

A paraneoplastic syndrome (PNS) is a set of symptoms and signs that can accompany the formation of a cancer but is not due to its direct infiltration or metastasis. PNS results from the secretion of peptides or hormones by tumor cells or from an immunological cross-reaction between the tumor antigens and host antigens. In the adult population, PNS affects up to 15% of patients with cancer, but data on pediatric patients remain lacking. The remarkable fact is that PNS can precede an oncology diagnosis, even by months or years. PNS can involve virtually any organ of the human body. In children, the most commonly involved are the nervous system (encephalitis, opsoclonus-myoclonus syndrome), skin (pemphigus, alopecia areata, pruritic skin, pyoderma gangrenosum, skin nevi), rheumatologic (dermatomyositis, vasculitis), liver (atrophic biliary syndrome, idiopathic cholestasis), endocrine system (hypercalcemia, syndrome of inadequate secretion of antidiuretic hormone), kidney (nephrotic syndrome), or hematopoietic system (hemolytic anemia, thrombocytopenia, eosinophilia, thrombotic macroangiopathy, leukomoid reaction). PNS can accompany all childhood cancers, but is most common in Hodgkin lymphoma, acute lymphoblastic and myeloid leukemia, neuroblastoma, Wilms tumor, and sarcoma. Diagnosis of PNS should begin as early as the suspicion of its unusual course, lack of response to standard treatment, or prolonged duration. Diagnosis should include typical disease-specific tests and simultaneous imaging of the head and neck, abdomen, and pelvis, as well as a bone marrow biopsy to look for malignancy. PNS treatment mainly includes anti-tumor therapy and sometimes additional immunosuppressive therapy. This article aims to review PNS in children with malignancy.

A nationwide survey of opsoclonus-myoclonus syndrome in Japanese children

BACKGROUND

Opsoclonus-myoclonus syndrome (OMS) is a rare neurological disease characterized by opsoclonus, myoclonus, ataxia, and behavioral changes. The aim of our study was to investigate the epidemiological characteristics of OMS in Japan and to clarify the association between therapy and prognosis.

METHODS

We retrospectively collected the data from 626 Japanese medical institutions from 2005 to 2010, and analyzed the clinical features of pediatric patients with OMS based on the data.

RESULTS

In this survey, there were 23 patients (10 males and 13 females). The median ages at the disease onset and the time of study were 16.5 months (range: 11-152 months) and 54 months (range: 24-160 months), respectively. The principal symptoms were opsoclonus (23 patients, 100%), myoclonus (21 patients, 91.3%), and ataxia (23 patients, 100%). The related factors were neuroblastoma (10, 43.5%), infection (9, 39.1%), and immunization (2, 8.7%). The treatments for OMS were included intravenous immunoglobulin (17, 73.9%), methylprednisolone pulse (13, 56.5%), oral prednisolone (12 patients, 52.2%), and chemotherapy and/or operation for the underlying tumors (6, 26.1%), and rituximab (2, 8.7%). Complete remissions were obtained in 35.3%, 23.1%, 33.3%, 66.7%, and 100% of these treatments, respectively. At the latest follow-up period, 8 (34.8%) and 17 patients (73.9%) showed neurological sequelae of motor and intellectual functions, respectively. Patients whose treatment was started more than 30 weeks after the disease onset suffered from the severest neurological sequelae (OMS severity 4) more frequently than those less than 30 weeks (p=0.022).

CONCLUSION

The annual incidence of OMS was estimated to be 0.27-0.40 cases per million in Japanese children. More than 70% of OMS patients had neurological sequelae, especially intellectual function. Early effective treatments within 30 weeks after the onset may be required to prevent the serious neurological outcome.

Paraneoplastic neurologic syndromes in children: a review article

OBJECTIVE

Paraneoplastic neurological syndromes (PNS) were initially defined as neurological syndromes with unknown etiology that often associate with cancer. This broad definition may lead to misconception that any neurological syndrome, which coincides with a cancer might be considered as PNS. In the last two decades it has been suggested that PNSs are mainly immune-mediated. The detection of onconeural antibodies has been very helpful in indicating the existence of a tumor and defining a given neurological syndrome as paraneoplastic. However, PNS may occur without onconeural antibodies, and the antibodies can occur with no neurological syndrome; thus, their presence should not be the only condition to define a neurological syndrome as paraneoplastic. Diagnosis of paraneoplastic syndromes in children may result in early detection and treatment of the pediatric cancer and can reduce the neurological damage that is the major source of morbidity in children with successfully treated tumors. This study reviews the presenting symptoms, immunology, and management options for paraneoplastic syndromes, focusing on those most commonly reported in children.