Rare but Characteristic Symptoms

Rare but characteristic symptoms of neuroblastoma are shown in Table 7.1.

Transverse Myelopathy

Transverse myelopathy can result from growth of a cervical, intrathoracic, or intraabdominal neuroblas-toma through neural foramina into the spinal canal. Approximately half of the patients with dumbbell lesions initially present with neurological symptoms (Katzenstein et al. 2001), but myelopathy may develop soon afterwards,e.g., during surgery; thus,the degree of intraspinal tumor extension should be evaluated by MRI before surgery in order to avoid decom pensation of a labile steady state. The neurological abnormalities associated with these tumors include motor deficit (>95%), radicular or back pain (54%), sphincter abnormalities, (34%), and sensory (12%) deficits (de Bernardi et al. 2001). The frequency of complete neurological recovery appears to be inversely correlated with the severity of the presenting neurological deficits (Katzenstein et al. 2001). Forty to 50% of the severely affected surviving children experience long-term neurological sequelae (Katzenstein et al. 2001; de Bernardi et al. 2001). There is a high likelihood of permanent neurological dysfunction in patients who experience neurological symptoms for more than 1 week prior to the initiation of treatment. Chemotherapy, radiotherapy, and surgical decompression with laminectomy have been shown to result in similar rates of neurological recovery, but chemotherapy may be associated with fewer long-term sequelae (Katzenstein et al. 2001; de Bernardi et al. 2001).

Opsomyoclonus-ataxia syndrome

The opsomyoclonus-ataxia syndrome (Kinsbourne syndrome) is characterized by rapid, irregular movements of the eyes ("dancing eyes"; may continue during sleep) and/or by myoclonus and ataxia of the limbs ("dancing feet"), the trunk, and the eyelids.

Many patients experience developmental delays including cognitive and motor delays, language deficits, and behavioral abnormalities (Russo et al. 1997; Rudnick et al. 2001). The pathogenesis is still unclear, although extensive lymphocytic infiltration of the tumor tissue (compared with neuroblastoma patients without opsomyoclonus) (Cooper et al. 2001) and the presence of anti-neuronal antibodies (Rudnick et al. 2001) suggest that the disorder is immunologically mediated. Removal of the primary tumor may not necessarily cure the neurological manifestation. The pharmacological treatment of the neurological symptoms includes glucocorticoids (prednisone or ACTH),high-dose immunoglobulins, and cytotoxic drugs. Anecdotal reports indicate that 60-80% of the patients respond to treatment, but long-term neurodevelopmental results are still poor (60-70% permanent handicaps). The survival rate of children with opsomyoclonus-ataxia syndrome is generally favorable, because the majority of them have localized tumors and present at a young age (Rudnick et al. 2001) (see Chaps. 11 and 13; Table 7.1).

Horner's Syndrome

Horner's syndrome (ptosis, miosis, enophthalmos) and heterochromia (difference in color between the two irises) is caused by disturbances of the cervical sympathetic ganglia which are responsible for normal eye color and development. An association has been found with neuroblastoma only and not with other tumors of the same area (Jaffe et al. 1984) indicating an intimate cooperation between the ganglia and the neuroblastoma development.

Treatment-Resistant Diarrhea

The association of treatment-resistant diarrhea, hy-pokalemia, and dehydration with neuroblastoma is observed in approximately 4% of patients and is thought to result from overproduction of the vasoin-testinal peptide (VIP) by maturing neuroblastomas (El Shafie et al. 1983) or ganglioneuromas. It usually resolves after surgical removal of the primary tumor. The use of chemically designed VIP antagonists is still in the preclinical phase (Lilling et al. 1994).

Hypertension

Hypertension is usually caused by tumor pressure on the renal artery with consequent stimulation of the renin-angiotensin system, rather than by tumor secretion of vasoactive catecholamine metabolites (dopamine, epinephrine, norepinephrine). With chemotherapy hypertension can worsen before it gets better. If a- and p-blockers or angiotensin-con-verting-enzyme inhibitors fail to control the blood pressure and the tumor remains unresectable, one may consider surgically freeing the renal artery without attempting tumor resection.

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