Sharmistha Behera 1 , Bidisha Mahapatra 2 , Sasmita Sahu 3 , Sonali Sahoo

BACKGROUND The close proximity of the orbit and the paranasal sinuses, both of which share more than two-thirds of common walls makes the orbit too susceptible to infections spreading from the paranasal sinuses. In any case of proptosis indicating an orbital tumour, extension from a PNS lesion should be ruled out. MATERIALS AND METHODS The study was a retrospective descriptive study. Data taken from the patient's medical record during the period of July 2014- June 2017. A total of 32 cases of proptosis were studied all of which were secondary to paranasal sinus pathology. These cases were subject to routine clinical examination and investigations including CT and MRI scan. Histopathological diagnosis was obtained by biopsy in appropriate cases. RESULTS Out of 32 patients, males were 68.75% (n=22) and females were 31.25% (n=10). The largest age group are in the age range 41-50 years (31.25%, n=10) and in age group 0-10 years (31.25%). Out of the whole, 13 (40.6%) of them were due to sinusitis, 6 (18.75%) due to sinonasal malignancy, all of which were histopathologically confirmed to be squamous cell carcinoma of maxillary sinus, 6 (18.75%) cases were of mucoceles from frontoethmoidal origin, 4 (12.50%) cases were of fibrous dysplasia of maxillary sinus, 2 (6.25%) case was of schwannoma of frontal sinus origin and 1 (3.12%) case of Langerhans cell histiocytosis of maxillary sinus. In our study, proptosis was commonest presenting complaint in all 32 patients followed by nasal obstruction (62.5%), reduced vision (25%), facial asymmetry (25%), redness of eye (18.75%) and double vision (12.50%). Out of all investigative modalities, biopsy was found to be the most accurate followed by CT scan brain, PNS and orbit. CONCLUSION Due to close proximity, nasal and PNS diseases through bone erosion or preformed pathways can invade the orbit and cause proptosis. Longstanding optic nerve compression by orbital encroachment of PNS lesion can lead to blindness due to optic atrophy. Therefore, early diagnosis and treatment is essential to prevent grave consequences as blindness.