Nasopharyngeal B-cell lymphoma with pan-hypopituitarism and oculomotor nerve palsy: a case report and review of the literature

BACKGROUND: Primary nasopharyngeal lymphoma (NPL) is a very rare tumor of Waldeyer ring (WR) lymphoid tissue. It is challenging to differentiate lymphoma infiltration of pituitary from a pituitary adenoma, meningioma infiltration, and other sellar lesions to plan a suitable treatment strategy. We presented for the first time a unique case of NPL with an unusual presentation of oculomotor nerve palsy associated with pan-pituitary involvement in a diabetic patient. CASE PRESENTATION: A 64-year old diabetic woman with no previous history of malignancy presented with intermittent diplopia for about the last nine months. Severe headache, left eye ptosis and hypoglycemic episodes were added to her symptoms after a while. Further complaints include generalized weakness, loss of appetite, generalized musculoskeletal pain, and 6–7 kg weight loss within six months. Her family history was unremarkable. Physical examinations of eyes indicated left eye 3rd, 4th, and 6th nerve palsy. But, she was not anisocoric, and the pupillary reflexes were normal on both eyes. No lymphadenopathy, organomegaly and other abnormalities were found. Magnetic resonance imaging (MRI) showed a heterogeneous enhancement in the seller and suprasellar regions, enlargement of the stalk, parasellar dural enhancement and thickening of the sphenoid sinus without bone erosion. Also, both cavernous sinuses were infiltrated and both internal carotid arteries were encased by the neoplastic lesion. It suggested an infiltrative neoplastic lesion which compressed the cranial nerves. Pituitary hormone levels assessment indicated a pan-hypopituitarism. Following nasopharyngeal mucosal biopsy, the immunohistochemistry (IHC) findings revealed a low-grade non-Hodgkin’s B-cell lymphoma. Systemic workup, including cerebrospinal fluid (CSF) studies, bone marrow aspiration, chest and abdominopelvic high-resolution computed tomography (HRCT) indicated no other involvement by the lymphoma. After chemotherapy courses, central adrenal insufficiency, partial central diabetes incipidious (CDI) and central hypothyroidism have been resolved. To our best knowledge, we found 17 cases of NPL with cranial nerve palsy, 1 case of NPL with pan-hypopituitarism and no NPL case with both cranial nerve palsy and pituitary dysfunction. CONCLUSIONS: The incidence of cranial neuropathy in patients with diabetes should not merely be attributed to diabetic neuropathy without further evaluation.