Solid Component Volume as a Proxy to Identify Distinct Hemangioblastoma Populations.

BACKGROUND

Posterior fossa hemangioblastomas usually consist of a small solid nodule with a large cyst, while more rarely they present as a large solid mass with a small or absent cyst, which can be surgically challenging. We sought to investigate the potential existence of multiple distinct hemangioblastoma populations using tumor volumetric data as an indicator.

METHODS

We conducted a retrospective review of surgically treated hemangioblastomas between 2005 and 2019 in our unit, including clinical notes, preoperative magnetic resonance imaging volumetric analysis of the solid component of the tumor, and pathology. Finite Gaussian mixture modeling was applied on the solid component volume dataset to identify potential underlying Gaussian distributions with their associated characteristics. Nonparametric Mann-Whitney U tests were used to investigate significance of differences (P < 0.05) in solid component volume and different variables (Von Hippel-Lindau disease, extent of resection, outcome).

RESULTS

A total of 68 consecutive patients were included. Solid component volumes followed a multimodal distribution (median = 1287 mm, interquartile range of 3428 mm). The best-fit finite Gaussian mixture modeling model identified 3 statistically significant different (P = 0.001) potential mixture components: X (219 ± 187 mm) X (2686 ± 1299 mm), and X (10,800 ± 5514 mm). The second-best model detected 2 significantly different (P = 9.99e) mixture components Y (222 ± 189 mm) and Y (5391 ± 5094 mm). A significant difference in solid component volume was found between patients with favorable and unfavorable outcome (P = 0.002).

CONCLUSIONS

This study has shown preliminary evidence that large solid hemangioblastomas may constitute a completely distinct population, rather than a variant of one large group of hemangioblastomas.