Mechanism of Split Cranial Sutures in Metastatic Neuroblastoma

Skull metastases and split cranial sutures frequently occur in patients with neuroblastoma (4, 5, 16). This communication emphasizes the pattern of cranial and intracranial metastases found at autopsy. Radiographic and clinical findings are correlated. Material The present series consists of ten patients with neuroblastoma for whom complete autopsy evaluation was available. These were selected from more than 200 cases coded as neuroblastoma at the University of Michigan Medical Center since 1940. Cases with no autopsy, incomplete autopsy, disputed tissue diagnosis, or incidental finding of neuroblastoma after death from other causes have been excluded. Many of the patients died at home or in other hospitals. Retinoblastomas and neuroblastomas originating from olfactory epithelium (esthesioneuroblastoma, esthesio-neuroepithelioma) or other tissue inside the cranium have been eliminated. Findings A summary of the roentgenographic and necropsy findings for the 10 patients is presented in Table I. Metastases to the skull were observed at autopsy in 5 cases. The bony metastases were diffuse and usually continuous with a soft, nodular, often hemorrhagic tumor plaque which elevated the epicranium (Fig. 1). This nodularity was palpable through the scalp. The bony metastases in all 5 cases were continuous with a similar tumor plaque in the epidural space (Figs. 2 and 3). The tumor appeared to separate the dura mater from the inner table of the skull. The dural metastases tended to be generalized, involving both the convexity and the base, but strongly favoring the external surface of the dura mater. The dura seemed to act as a barrier to deeper penetration of neoplasm. Minor extensions of the tumor to the internal aspect of the dura were found in only 2 cases. It should be noted that 1 patient without cranial involvement at autopsy (S. G.) died of operative complications and not directly of neuroblastoma. The leptomeninges and brain were free of neoplasm (Figs. 3 and 4) on both gross and microscopic examination in all 10 cases. The pachymeningeal tumor plaque could in every instance be easily lifted away from the leptomeninges. When the dural masses were large, molding of the brain was present (Fig. 3). The dural venous sinuses were patent in 4 of the patients with dural metastases. The autopsy protocol of the fifth case did not describe the appearance of the dural venous sinuses. Split cranial sutures were noted by the prosector in 3 of the 5 cases with cranial and dural metastases. He did not comment on the appearance of the sutures in 1 case and recorded absence of split cranial sutures in 6 of the total group of 10 patients.