Brain cryptococcoma mimicking a glioblastoma in an immunocompetent patient: A rare case report and comprehensive review

Abstract

Background: Cryptococcosis is an invasive fungal infection primarily affecting lungs and potentially spreading to the central nervous. This fungal infection might be misdiagnosed as other infection diseases, such as tuberculosis; granulomatous diseases, like sarcoidosis; and even neoplastic diseases. Some previous reports described cases of cryptococcomas resembling brain tumors. In this paper, we present a very rare presentation of brain cryptococcoma mimicking a malignant glioma. To the best of our knowledge, this is the third case description in the literature.

Case description: A 64-year-old male patient presented at the hospital with a history of progressive frontal headache for 1 month, becoming moderate to severe, associated with visual changes, without nausea or vomiting. No fever was reported. He was a heavy smoker and denied other relevant previous medical data. Neuroimage disclosed a right temporal expansive lesion initially considered a malignant glioma. The patient underwent a right temporal craniotomy and biopsy revealed a cryptococcoma.

Conclusion: Cryptococcomas characteristics in magnetic resonance are quite nonspecific. They should always be included in differential diagnosis of expansive brain lesions, both malignant and benign. Therefore, once cryptococcomas may resemble like other intracranial expansive lesions, biopsy should always be carried out to clarify diagnosis and avoid inadequate treatment and definition of prognosis only based on radiological patterns.

Keywords: Brain neoplasm; Differential diagnosis; Neurocryptococcosis; Surgery.

Figure 1:

Preoperative neuroimage of patient. We present preoperative computed tomography and MR in sequences T1, T2, FLAIR, and T1 with gadolinium and diffusion. MR disclosed an expansive right temporal lesion. It was solid-cystic, hyperintense at T1, and hypointense at T2, with heterogeneous enhancement after gadolinium injection.

Figure 2:

MR spectroscopy evaluation showing reduction in N-acetyl aspartate levels with an increase in choline levels and an increase in lactate levels.

Figure 3:

MR perfusion evaluation displaying increased cerebral perfusion.

Figure 4:

Histology image. In (a), histological section stained by H and E ×40, brain parenchyma is shown, showing a moderate mixed inflammatory infiltrate with a foreign body-type giant cell reaction permeating capsulated structures. (b) This same cut, enlarged at 100×, revealing a moderate mixed inflammatory infiltrate and round to oval capsulated structures. In (c), a GomoriGrocott stain, enlarged by ×40, reveals the silver impregnation, showing multiple capsulated structures. Finally, (d), in the same coloration, at 100×, it is possible to notice capsulated structures, round to oval with thin cell walls of variable size (3.5–8 μm in diameter). Arrows show inflammatory infiltrate and round to oval capsulated structures compatible with cryptococcoma.

Figure 5:

Comparison of preoperative MR (left) and postoperative MR (right). MR revealed good surgical resection of lesion.