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Objective: Tuberous sclerosis is a rare genetic condition caused by TSC1 or TSC2 mutations that can be inherited, sporadic, or the result of somatic mosaicism. Subependymal giant-cell astrocytoma (SEGA) is a major diagnostic feature of tuberous sclerosis complex (TSC). This study aimed to present a series of cases in which a pathological diagnosis of SEGA was not diagnostic of tuberous sclerosis., Methods: The authors retrospectively reviewed a clinical case series of 5 children who presented with a SEGA tumor to Johns Hopkins All Children's Hospital and St. Louis Children's Hospital between 2010 and 2022 and whose initial genetic workup was negative for tuberous sclerosis. All patients were treated with craniotomy for SEGA resection. TSC genetic testing was performed on all SEGA specimens., Results: The children underwent open frontal craniotomy for SEGA resection from the ages of 10 months to 14 years. All cases demonstrated the classic imaging features of SEGA. Four were centered at the foramen of Monro and 1 in the occipital horn. One patient presented with hydrocephalus, 1 with headaches, 1 with hand weakness, 1 with seizures, and 1 with tumor hemorrhage. Somatic TSC1 mutation was present in the SEGA tumors of 2 patients and TSC2 mutation in 1 patient. Germline TSC mutation testing was negative for all 5 cases. No patient had other systemic findings of tuberous sclerosis on ophthalmological, dermatological, neurological, renal, or cardiopulmonary assessments and thus did not meet the clinical criteria for tuberous sclerosis. The average follow-up was 6.7 years. Recurrence was noted in 2 cases, in which 1 patient underwent radiosurgery and 1 was started on a mammalian target of rapamycin (mTOR) inhibitor (rapamycin)., Conclusions: There may be intracranial implications of somatic mosaicism associated with tuberous sclerosis. Children who are diagnosed with SEGA do not necessarily have a diagnosis of tuberous sclerosis. Tumors may carry a TSC1 or TSC2 mutation, but germline testing can be negative. These children should continue to be followed with serial cranial imaging for tumor progression, but they may not require the same long-term monitoring as patients who are diagnosed with germline TSC1 or TSC2 mutations.

An intradural somatic-to-autonomic anastomosis, or Xiao procedure, has been described to create a "skin-CNS-bladder" reflex that improves bladder and bowel function in patients with neurogenic bladder and bowel dysfunction. The authors present their experience with a 10-year-old boy with chronic neurogenic bladder and bowel dysfunction related to spinal cord injury who underwent the Xiao procedure. After undergoing a left L-5 ventral root to left S2-3 intradural anastomosis, the patient reported that his bladder and bowel dysfunction improved between 6 and 12 months. Two years after the procedure, however, he reported that there was no change in his bladder or bowel dysfunction as compared with his condition prior to the procedure. Frequent, systematic multidisciplinary evaluations produced conflicting data. Electrophysiological and histological evaluation of the previously performed anastomosis during surgical reexploration 3 years after the Xiao procedure revealed that the anastomosis was in anatomical continuity but neuroma formation had prevented reinnervation. Nerve action potentials were not demonstrable across the anastomosis, and stimulation of the nerve above and below the anastomosis created no bladder or perineal contractions. This is the first clinical report on the outcome of the Xiao procedure in a child with spinal cord injury outside of China. It is impossible to draw broad conclusions about the efficacy of the procedure based on a single patient with no demonstrable benefit. However, future studies should carefully interpret transient improvements in bladder function, urodynamic findings, and the patient's ability to void in response to scratching after the Xiao procedure. The authors' experience with the featured patient, in whom reinnervation could not be demonstrated, suggests that such changes could be related to factors other than the establishment of a skin-CNS-bladder reflex as a result of a somatic-to-autonomic anastomosis.

Object: Intramedullary spinal cord lipomas not associated with dysraphism are infrequently reported. When present, they typically occur in children and have a predilection for the cervical and thoracic spinal cord. The authors review the presentation, treatment, and disease course in 5 pediatric patients, and compare the outcomes with previously reported cases., Methods: With institutional review board approval, a retrospective chart review was undertaken at Children's Hospital Los Angeles., Results: Four patients with intramedullary spinal cord lipomas and 1 patient with a lipoblastoma, none associated with dysraphism, were retrospectively reviewed. There were 2 boys and 3 girls ranging in age from 2 months to 4 years. Four patients underwent a laminectomy or laminoplasty with one or more subtotal resections. One patient initially underwent a decompressive laminoplasty without debulking. The median follow-up was 8 years (range 12 months-11 years). Two patients had regrowth of their lipoma, necessitating a second surgery in one patient and 3 debulking surgeries in the other. Postoperatively, 3 patients developed mild kyphosis, none significant enough to require orthopedic intervention. One patient underwent a stabilization procedure at the time of the initial laminectomy and tumor debulking. No patient received chemotherapy or radiation. At the most recent follow-up visit, patients demonstrated improved neurological function when compared with preoperative status., Conclusions: In addition to a decompressive laminectomy, debulking of the lipoma provides the best long-term neurological outcome. Gross-total excision is not warranted and usually is not possible. Long-term follow-up is needed, and repeat debulking of the lipoma is indicated if there is an increase in tumor size due to hyperplasia of residual adipocytes, when tumor growth is associated with neurological deterioration.

Papillary glioneuronal tumors are a newly recognized type of brain neoplasm characterized by prominent pseudopapillary structures and glioneuronal elements. All prior cases have shown that these tumors have an indolent course. The authors present 2 patients with an aggressive variant of the tumor. The first patient had dissemination of her tumor and the second had local spreading. Therefore, the authors conclude that papillary glioneuronal tumors do not always behave in a strictly benign fashion.

Giant cell tumors of the bone are rare, locally aggressive lesions that primarily affect the epiphyses of long bones. These tumors can occur in the skull, principally in the sphenoid and temporal bones. Symptoms of these tumors depend on their site of origin but typically include headache, pain, visual field defects, and conductive hearing loss. Histologically, these tumors consist of three cell types: osteoclast-like multinucleated giant cells; round mononuclear cells resembling monocytes; and spindle-shaped, fibroblast-like stromal cells. Radiographically, the tumors appear osteolytic and radiolucent without a sclerotic border. These tumors typically present in the third to fourth decades of life and rarely occur in patients under 20 years of age. The small number of studies of giant cell tumors of the skull has focused on the adolescent and adult populations. The authors report two cases of giant cell tumors of the skull in pediatric patients. In the first case, a 2-year-old girl presented with swelling behind the right ear. In the second case, a 7-week-old girl presented with a mass within the external auditory canal. Both patients underwent metastatic workup and biopsy procedures before resection of the tumor. Both case reports contribute to the literature of giant cell tumors of the skull by describing this condition in pediatric patients. To the authors' knowledge, these cases represent the youngest two patients with giant cell tumors of the skull yet described.

Object: The management of pediatric intraventricular tumors is highly dependent on identification of the tumor type. Choroid plexus papillomas, a common intraventricular tumor in children, can be difficult to distinguish radiographically from choroid plexus carcinomas and other common pediatric central nervous system (CNS) tumors. In this study to overcome the limitations of current noninvasive imaging modalities, the authors use novel magnetic resonance (MR) spectroscopy techniques in vivo to elucidate the identifying biochemical features of choroid plexus tumors that may facilitate diagnosis and treatment., Methods: Based on an Internal Review Board-approved protocol, six children with newly diagnosed, untreated intraventricular brain tumors were identified. On retrospective review, this series included three choroid plexus papillomas and three choroid plexus carcinomas. Single-voxel proton MR spectroscopy with a short echo time was performed, and absolute metabolite concentrations (in mmol/kg) were determined using fully automated quantitation. These results were compared with MR spectroscopy profiles obtained in 54 other untreated CNS neoplasms in children. The myo-inositol (mI) level was significantly higher in choroid plexus papillomas (> 10 mmol/kg), uniquely distinguishing these tumors from choroid plexus carcinomas and all other tumors. Choroid plexus carcinomas, on the other hand, had significantly elevated levels of choline when compared with choroid plexus papillomas., Conclusions: In this study the authors find that mI is a biochemical constituent that uniquely identifies choroid plexus papillomas and can be used as a noninvasive means of diagnosis and for follow-up evaluations in patients with this disease.