History: 32-year-old man with ataxia, nausea, and vomiting
Findings: An axial T1-weighted image shows a large cystic mass within the cerebellum that demonstrates intense enhancement of the mural nodule after contrast administration.
A contrast enhanced CT image of the abdomen reveals numerous cysts within the kidneys and pancreas.
WIKI: Hemangioblastomas (capilliary hemangioblastomas) are tumors of the central nervous system that originate from the vascular system usually during middle-age. Sometimes these tumors occur in other sites such as the spinal cord and retina. They may be associated with other diseases such as polycythemia (increased blood cell count), pancreatic cysts and Von Hippel-Lindau syndrome (VHL syndrome). Hemangioblastomas are most commonly composed of stromal cells in small blood vessels and usually occur in the cerebellum, brain stem or spinal cord. They are classed as grade one tumors under the World Health Organization‘s classification system.
A mural nodule is a small nubbin of solid tissue on the inner wall of a cyst. It is another component of a complex cyst. Complex as opposed to simple cysts are at a higher risk for harboring malignancy and so usually require further evaluation
Diagnosis: Cerebellar hemangioblastoma in a patient with von Hippel-Lindau syndrome.
People with von Hippel-Lindau syndrome commonly develop cysts in the kidneys, pancreas, and genital tract. They are also at an increased risk of developing a type of kidney cancer called clear cell renal cell carcinoma and a type of pancreatic cancer called a pancreatic neuroendocrine tumor.
Discussion: Hemangioblastomas are rare tumors accounting for <3% of all intracranial neoplasms and typically occur in patients 20-50 years old. Hemangioblastomas occur either sporadically or as a manifestation of von Hippel-Lindau syndrome. Von Hippel-Lindau syndrome is inherited as an autosomal dominant disorder linked to a defect on chromosome 3. In addition to hemangioblastomas of the cerebellum, brainstem, and cord, non-central nervous system manifestations of von Hippel-Lindau syndrome include cysts of the kidneys, pancreas, and liver as well as renal cell carcinoma, microcystic adenoma of the pancreas, and pheochromocytoma.
Cystic neoplasms of the pancreas are less common than solid tumors, and portend a better prognosis.
Hemangioblastomas in von Hippel-Lindau syndrome are multiple in up to 40% of cases and typically present at least 10 years earlier than those occurring in patients without the syndrome. To diagnose von Hippel-Lindau syndrome, multiple hemangioblastomas or one hemangioblastoma with other visceral manifestations of the disease are required. Greater than 50% of the hemangioblastomas are cystic, with a mural nodule (A mural nodule is a small nubbin of solid tissue on the inner wall of a cyst) that demonstrates intense enhancement. If the cyst wall is thick or enhanced, other neoplasms should be considered. A pilocytic astocytoma (A pilocytic astrocytoma is a brain tumor that originates from star-shaped cells called astrocytes. Astrocytes are a kind of glial cell, cells that support and nourish neurons in the brain. An astrocytoma is a type of glioma)or metastasis may also present as a cystic mass of the fourth ventricle, but patients with these tumors would not be expected to have the other manifestations of von Hippel-Lindau syndrome.
Aunt Minnie’s Pearls
- Multiple cystic masses with an enhancing mural nodule or one mass with specific visceral manifestations = von Hippel-Lindau syndrome.
- Visceral manifestation of von Hippel-Lindau syndrome = renal, pancreatic, and liver cysts, renal cell carcinoma, pheochromocytoma, and retinal hemangioblastomas.