(CR19) Isolated Third Cranial Nerve Palsy as Presenting Sign of Sinonasal Undifferenciated Carcinoma

Introduction:

Sinonasal undifferenciated carcinoma (SNUC) is an extremely rare and aggressive malignancy which can present with variety of symptoms.

Case Report/Description :

We report a case of SNUC which initially presented with isolated unilateral third cranial nerve palsy. A 54 years old gentleman with dyslipidemia came with complain of binocular diplopia for 3 days. His visual acuity for both eye was 6/9. Ocular examination revealed right partial ptosis with limited elevation, adduction and depression of right eye with pupil sparing. Diagnosis of right medical third cranial nerve   palsy due to mononeuritis multiplex was made. However patient came back with right eye reduced vision associated with headache and worsening diplopia after 2 weeks. Right eye visual acuity was counting finger. Worsening ophthalmoplegia noted with involvement of right fourth, fifth and sixth cranial nerve. Urgent CT scan revealed a huge sinonasal mass with extension to the right orbit, compressing the extraocular muscles and the right optic nerve. It also extended intracranially involving the cavernous sinus and right medial temporal lobe. Endoscopic biopsy was done and histopathogical examination revealed malignant cells, consistent with SNUC. The patient then referred for chemotherapy and radiotherapy.

Discussion/Conclusion:

In conclusion, SNUC may present with mainly ocular problem and isolated cranial nerve palsy can be red herring of underlying serious pathology. Since it is rare malignant tumor, it is often overlooked and difficult to diagnose accurately. Thereby history taking, thorough examination extremely important to decide for early neuroimaging, as early diagnosis may lead to a better outcome in SNUC.