hemangioblastoma

Definition: Capillary hemangioblastomas are benign tumors, mostly observed in the central nervous system (intraneural hemangioblastoma). However, it can be observed elsewhere (extraneural hemangioblastoma).

Images

 Hemangiomblastoma of cerebellum

• https://twitter.com/KUSAURAP/status/733543922543136770
• https://twitter.com/marammussab/status/763974593287557120

renal extraneural hemangioblastoma

• https://twitter.com/priyaraomd/status/1256209697184628737

It is a tumor of unknown histogenesis that arises primarily in the posterior cranial fossa, either as a sporadic event or in association with von Hippel-Lindau disease (VHL).

Capillary hemangioblastomas of the central nervous system are benign tumors and occur either sporadically or in 25% of cases as a manifestation of von Hippel-Lindau (VHL) disease. VHL alleles are reported to be inactivated in up to 50% of sporadic and 100% in VHL-associated hemangioblastomas.

A rarer cellular and a more common reticular variant can be distinguished on the basis of the abundance of the stromal cell component, with the cellular variant being significantly associated with a greater probability of recurrence.

They are characterized histologically by the 2 main components of large vacuolated stromal cells and a rich capillary network and can be subclassified into 2 variants on the basis of the abundance of the stromal cell component:
 the rarer cellular hemangioblastomas defined by zellballen-like cellular clusters of uniform tumor cells (11.4%)
 the more common reticular subtype showing abundant capillaries and stromal cells.

CGH (16949923)

 Losses of

• Chr.19 losses (35%)
• Chr.6 losses (30%),
• 22q losses (15%),
• Chr. 3 losses

 Gains

• Chr.4 gain

Cellular and reticular variants of hemangioblastoma differ in their cytogenetic profiles (16949923).

Molecular biology

 3p25 LOH: VHL locus (15535134)
 6q LOH (15535134, 11943349)
 22q13 LOH (15343513)

References

 PAX2(-)/PAX8(-)/Inhibin A(+) Immunoprofile in Hemangioblastoma: A Helpful Combination in the Differential Diagnosis With Metastatic Clear Cell Renal CellCarcinoma to the Central Nervous System. Carney EM, Banerjee P, Ellis CL, Albadine R, Sharma R, Chaux AM, Burger PC, Netto GJ. Am J Surg Pathol. 2011 Feb;35(2):262-7. PMID: 21263247

 Nonaka D, Rodriguez J, Rosai J. Extraneural Hemangioblastoma: A Report of 5 Cases. Am J Surg Pathol. 2007 Oct;31(10):1545-1551. PMID: 17895756

 Rickert CH, Hasselblatt M, Jeibmann A, Paulus W. Cellular and reticular variants of hemangioblastoma differ in their cytogenetic profiles. Hum Pathol. 2006 Nov;37(11):1452-7. PMID: 16949923

 Patton KT, Satcher RL Jr, Laskin WB. Capillary hemangioblastoma of soft tissue: report of a case and review of the literature. Hum Pathol. 2005 Oct;36(10):1135-9. PMID: 16226115

 Roy S, Chu A, Trojanowski JQ, Zhang PJ. D2-40, a novel monoclonal antibody against the M2A antigen as a marker to distinguish hemangioblastomas from renal cell carcinomas. Acta Neuropathol (Berl). 2005 May;109(5):497-502. PMID: 15864611

 Michal M, Vanecek T, Sima R, Mukensnabl P, Boudova L, Brouckova M, Koudepa K. Primary Capillary Hemangioblastoma of Peripheral Soft Tissues. Am J Surg Pathol. 2004 Jul;28(7):962-966. PMID: 15223969