Contribution of advanced neuroimaging in diagnosis of cerebral syphilitic gumma: a case report

Abstract

Background: Cerebral syphilitic gumma is a rare intracranial infectious disorder. Without a clear history of syphilis and comprehensive serological examinations, it's challenging to diagnose it accurately prior to surgery through routine magnetic resonance imaging (MRI). Advanced neuroimaging techniques have been widely used in diagnosing brain tumors, yet there's limited report on their application in cerebral syphilitic gumma. This report presents a case of an elderly male patient with cerebral syphilitic gumma and analyzes its characteristics of advanced neuroimaging.

Case presentation: A 68-year-old male patient was admitted to our institution presenting with bilateral hearing loss complicated with continuing headaches without obvious cause. Laboratory tests indicated positive treponema pallidum. Conventional MRI showed nodules closely related to the adjacent meninges in bilateral temporal lobes. The patient underwent surgical resection of the nodule in the right temporal lobe due to the mass effect and the final pathological diagnosis revealed cerebral syphilitic gumma.

Conclusions: With the return of syphilis in recent years, accurate diagnosis of cerebral syphilitic gumma is a matter of great urgency. Advanced neuro-MRI can serve as a significant complement to conventional MRI examination.

Keywords: Advanced neuroimaging; case report; cerebral syphilitic gumma; intracranial neoplasm; magnetic resonance imaging.

FIGURE 1

(A–C) The right temporal lobe showed a nodular which was characterized by hypointensity on T1 and hyperintensity on T2, with significant edema zone. There also showed slightly edema without clear lesion in the left temporal lobe. The cysts didn’t suppress on FLAIR. (D) Enhanced axial T1-weighted image showed significant enhancement of lesions in the bilateral temporal lobes. The adjacent meninges were enhanced, with a characteristic “dural tail”. (E–H) DCE parameters analyzed based on the Tofts model: Ktrans, Kep, Ve and iAUC.

FIGURE 2

(H) Conventional Diffusion-Weighted Imaging (DWI) (b = 1000) shows the lesion with iso-signal. (A) F map, (B) D map, (C) D map, (D) rBF map from intravoxel incoherent motion (IVIM) image. (E) DDC map, (F) α map, (G) sADC map from stretched exponential model (SEM) image.

FIGURE 3

(A) Amide proton transfer-weighted imaging shows increased signal on the right side of the lesion, while the signal on the left lesion is consistent with normal brain tissue. (B) Positioning image of single-voxel magnetic resonance (MR) spectroscopy. (C) Magnetic Resonance Spectroscopy Imaging shows a high Cho peak, a low Cr and NAA peak, Cho/NAA ratio greater than 1, and a negative Lip and Lac peak was observed at 1.33 ppm.

FIGURE 4

Postoperative pathology reveals fibrous tissue proliferation accompanied by numerous lymphocytes and plasma cells, scattered focally within granulomatous-like structures. Endothelial cell proliferation is observed in small arteries within the lesion, leading to luminal narrowing/solidification. Lymphoplasmacytic infiltration surrounds the vascular walls, histologically consistent with an inflammatory process.