Intracranial calcifications in childhood medulloblastoma: relation to nevoid basal cell carcinoma syndrome.

Background And Purpose: Medulloblastoma is one of the most common posterior fossa tumors to occur in children. Our purpose was to document the frequency, location, and time of occurrence of intracranial calcifications in cranial CT studies of children with medulloblastoma.

Methods: We retrospectively reviewed cranial CT studies of 56 patients diagnosed with medulloblastoma from 1983 through 1997 for the presence of intracranial calcifications. The findings were compared with 159 cranial CT studies of patients who were evaluated in the emergency department (control group). Thirty-two patients with medulloblastoma without shunts were compared with 118 patients from the control group without shunts. Similarly, 24 patients with medulloblastoma with shunts were compared with 41 patients from the control group with shunts.

Results: Overall, three (9%) patients with medulloblastoma without shunts, four (16%) patients with medulloblastoma with shunts, and four (10%) patients from the control group with shunts had falx calcification. Only the two children carrying the diagnoses of medulloblastoma and nevoid basal cell carcinoma syndrome, however, had calcification of the falx cerebri shown on the cranial CT scans obtained during the peridiagnostic period. Both were diagnosed with medulloblastoma before the age of 3 years and later developed jaw cysts and multiple basal cell carcinomas in the radiation field.

Conclusion: Previous studies have shown that falx calcification is a major component of nevoid basal cell carcinoma syndrome. Our two cases illustrate the importance of considering the diagnosis of nevoid basal cell carcinoma syndrome when falx calcification is present in young patients with medulloblastoma. If the concomitant diagnosis of nevoid basal cell carcinoma syndrome is made, alternative types of therapy should be sought to minimize radiation therapy sequelae.