Face of the Giant Panda Sign in Older Adults: Consider Lymphoma

A 72‐year‐old man with rapidly progressive gait disturbances and behavioral changes was referred to our Movement Disorders unit.

His brain magnetic resonance images (Fig. 1) showed the face of the giant panda sign, which is considered characteristic of Wilson's disease (WD). ¹ Although late‐onset WD cases are possible, his age and periventricular gadolinium‐enhanced lesions prompted us to consider other diagnostic possibilities. Cerebrospinal fluid examination revealed no intrathecal immunoglobulin synthesis, normal protein levels, and red and white cell counts. A brain biopsy was performed and revealed a diffuse B‐cell primary central nervous system lymphoma.

FIG. 1.

Brain magnetic resonance images.

Multiple‐choice question with Figure 1:

A.The red arrow refers to the eyes of the tiger sign.

B.The red arrow refers to the face of the giant panda sign.

C.This sign is usually seen in Wilson's disease.

D.Here, alternative diagnoses should be ruled out.

Correct answers: B, C, D.

Explanation in the text. The face of the giant panda sign (red arrows) is discernible on FLAIR (fluid‐attenuated inversion recovery) and T2‐weighted axial midbrain slice images: high signal intensity of the tegmentum with normal hypointense red nuclei and preserved signal intensity of the substantia nigra pars reticulata. Periventricular gadolinium‐enhanced lesions are indicative of an alternative diagnosis.

Other rare conditions such as Japanese B encephalitis (with bilateral hemorrhagic lesions in the thalami), Leigh's disease, methanol poisoning (with bilateral putaminal hemorrhagic necrosis), hypoxic‐ischemic encephalopathy, extrapontine myelinolysis, cysticercal granuloma of the midbrain (with ring‐enhancing gadolinium lesion), ² Maple syrup urine disease, glucaric aciduria type 1, non‐Wilsonian hepatolenticular degeneration (intense T1 shortening contrasts with the usual T1 hypointensities in WD), isoniazid‐induced ataxia and metronidazole neurotoxicity (red nucleus hyperintensities as “bright eyes” of the panda) may produce a face of the giant panda sign (supplemental references in Data S1).

In conclusion, the age of onset over 40 years, atypical, or gadolinium‐enhanced brain lesions in a case with the face of the giant panda sign should lead to further investigation to focus on treatable conditions.

Author Roles

(1) Research project: A. Conception, B. Organization, C. Execution; (2) Statistical analysis: A. Design, B. Execution, C. Review and critique; (3) Manuscript preparation: A. Writing of the first draft, B. Review and critique.

M.P.: 1A, 1B, 1C, 3A

L.S.: 1A, 1B, 3B

S.G.: 1A, 1B, 1C, 3B

Disclosures

Ethical Compliance Statement: Verbal and written informed consent were obtained from the subject. He was offered the opportunity to read this article and review the images but waived his right to do so. The authors confirm that the approval of an institutional review board was not required for this work. We confirm that we have read the journal's position on issues involved in ethical publication and affirm that this work is consistent with those guidelines.

Funding Sources and Conflicts of Interest: No specific funding was received for this work. The authors declare that there are no conflicts of interest relevant to this work.

Financial Disclosures for the Previous 12 Months: The authors declare that there are no additional disclosures to report.

Supporting information

Data S1. Supplemental references.

Data Availability Statement

Data sharing not applicable.