Diagnosis:
Tuberous sclerosis
• Tuberous sclerosis complex is an autosomal dominant disorder with the lesions in the central nervous system (CNS), including cortical tubers, subependymal nodules, and subependymal giant cell astrocytomas. The patients can present with seizures, mental retardation, behavioral problems and raised intracranial pressure.
• Other lesions in patients with tuberous sclerosis can include cutaneous lesions (hypomelanic macules, facial angiofibromas, periungal or subungal fibromas, and shagreen patches or fibrous hamartomas), and cardiac rhabdomyomas, pulmonary lymphagioleiomyomatosis, renal angiomyolipomas, and renal cysts.
• Two different genes are associated with tuberous sclerosis: TSC1 gene: hamartin located in chromosome 9q34, and TSC2 gene: tuberin located in chromosome 16p13.3.
• Histologically, cortical tubers show effacement of the neocortex with collections of large, bizarre cells and extensive fibrillary gliosis beneath the pia. Grossly, the cortical tubers are firm and scattered over the brain blurring the gray-white matter junction.
• Subependymal nodules are firm or calcified protrusions, single or in rows, more commonly in the walls of the lateral ventricles.
• Subependymal giant cell astrocytomas (SEGA) are the most common CNS neoplasm in TS patients. SEGAs are typically present in the wall of the lateral ventricles and are predominantly exophytic.
• SEGAs are benign, slow-growing, discrete neoplasms and are graded as WHO grade I tumors. Microscopically, many large plump cells with abundant glassy eosinophilic cytoplasm and large eccentric nuclei are present accompanied by elongated cells with smaller nuclei and fibrillar processes, forming a nodular appearance.
