Isolated oculomotor nerve palsy as a manifestation of diffuse large B cell lymphoma: A case report

Abstract

An isolated third nerve palsy presenting as the primary manifestation of a lymphoma is rare, with only few cases having been described. The present study reports an unusual case of a healthy 67-year old male diagnosed with isolated right oculomotor nerve palsy (ONP), who was found to have an underlying B cell lymphoma. The patient's medical records were accessed upon consent. A thorough physical examination, including stroke and infections work-ups were performed. A chest computerized tomography (CT), brain magnetic resonance imaging and positron emission tomography (PET) scans and a mediastinal tissue biopsy, were performed as part of systematic diagnostic evaluations. The current report suggests that a PET fluorodeoxyglucose study or a CT scan of the chest, abdomen and pelvis (with contrast) may help in the early diagnosis of a cancer responsible for ONP, particularly if brain vessel imaging does not show a posterior cerebral artery aneurysm as a cause for the defect.

Keywords: CSF; CT; MRI; cranial nerve; lymphoma; oculomotor; palsy.

Figure 1.

CTA chest image. A chest CTA revealed a large posterior mediastinal mass extending from about the level of the carina into the upper abdomen behind the crura of the diaphragm (as highlighted by the yellow dotted circle). CTA, computed tomography angiography.

Figure 2.

Histopathological images of the mediastinal biopsy specimen. (A) Large numbers of lymphocytes, medium to large, with oval or round nuclei containing fine chromatin and scanty cytoplasm (hematoxyclin and eosin staining, ×20 magnification). Immunohistochemical staining (compared with appropriate controls) revealed strong, positive expression for (B) CD20 (membranous, diffuse), (C) BSAP (nuclear, partial), (D) CD10 (membranous, diffuse), (E) BCL6 (nuclear), and (F) BCL2 (membranous). Tissue sections showed low expression for (G) multiple myeloma 1 (no nuclear staining) and (H) MYC. (I) High expression of proliferative marker Ki-67 (80%).

Figure 3.

Immunohistochemical control images. Normal tonsil tissue was used as a control showing both (A) positively stained lymphoid tissue and the (B) absence of staining for squamous mucosa. (C) Normal tonsil tissue showing strong MYC expression having >10% MYC positive lymphoid areas, with a weak, distinct staining of the mantle zone B-cells (~10%). (D) Normal tonsil tissue with MUM1 staining. (E) Normal renal proximal tubule epithelial cells stained with CD10 showing a strong, predominantly membranous and cytoplasmic staining; distal tubules showing absence of staining. MUM1, multiple myeloma 1. Magnifications: Panel A, C, D, ×400; panel B, ×200.

Figure 4.

A positron emission tomography scan showing the hyper-metabolic tissue of the lymphoma affecting the posterior mediastinum, bilateral kidneys and some bone marrow indicating disseminated disease (as highlighted by the yellow arrows).

Figure 5.

An magnetic resonance imaging of the L spine. (A) T1 without contrast and, (B) T1 with contrast showing diffuse leptomeningeal enhancement suspicious for the lymphoma spread.