The patient went on to have a lumbar puncture and lymph node biopsy.

Lumbar puncture

Cerebrospinal fluid: The smear contains a few lymphocytes as well as plasma cells and monocytes. No malignant cells are identified.

Lymph node biopsy

Right cervical lymph node core biopsy: The sections show lymph node parenchyma, skeletal muscle, fibroadipose tissue and some fibrinous material. The cell population is polymorphous, predominantly composed of lymphocytes, histiocytes and plasma cells. Germinal centers are not appreciable on H&E staining, however, there are scattered tingible body macrophages. There is no evidence of hyaline-vascular follicle change, mantle cell `onion skinning' or plasmacytosis. Eosinophils are not a feature. There is no sclerosis. No granulomas, atypical cells or necrosis are seen.

Immunohistochemistry highlights a mixed population of CD3+, CD5+ T-cells, CD20+, CD79a+ B-cells and CD68+ histiocyte population. CD21 and CD23 staining highlights one small dendritic cell meshwork associated with Bcl-6+ cells, consistent with a germinal center. There are scattered CD30+ immunoblasts. No atypical CD15, CD30 or PAX5 positive cells are seen. EBER-ISH shows scant positive small lymphocytes.

DIAGNOSIS: Non-specific reactive changes. There is no evidence of malignancy.

Treatment

The patient had a presumptive diagnosis of Tolosa-Hunt syndrome and was managed with steroids. There was little initial improvement and the treating clinicians were concerned that an alternative diagnosis existed (e.g. lymphoma, IgG4 disease, metastasis etc...)

The patient therefore underwent a cavernous sinus dural biopsy, which is usually not required in Tolosa-Hunt syndrome.

Cavernous sinus biopsy

Left cavernous sinus biopsy/lesion: The specimen consists of inflamed ganglion tissue and adjacent fibrous tissue with occasional small nests of meningothelial cells, SSTR2 positive on immunohistochemistry. Normal support cells are prominent around the ganglion cells. Immunohistochemistry highlights aggregates of reactive CD20-positive B cells and CD3-positive T cells. There is no nuclear atypia. Occasional plasma cells and rare neutrophils and eosinophils are admixed with the lymphocytes. There are no features of IgG4 disease on immunohistochemistry. Spirochete immunohistochemistry is negative.

DIAGNOSIS: Ganglion and fibrous tissue with mixed acute and chronic inflammation, and meningothelial hyperplasia. Consider infection and inflammatory causes.

Ongoing treatment

The findings remain consistent with a diagnosis of Tolosa-Hunt syndrome and the patient has made a good gradual recovery.