ORIGINAL ARTICLE The Role of Computed Tomography in the Evaluation of Paranasal Sinuses Lesions Bhumikaben P. Suthar 1 *, Divya Vaidya 2, Pukhraj P. Suthar 3. 1 Assistant Professor, 2 Third Year Resident, 3 Assistant Professor, Department of Radiodiagnosis. Baroda Medical College Vadodara, Gujarat, ABSTRACT BACKGROUND AND OBJECTIVES: Paranasal sinuses and their lesions are important challenge for clinicians. In the last 25 years,ct scan has become a useful diagnostic modality in the evaluation of PNS and an integral part of surgical planning. Our objective was to describe in detail, the lesions and their correlates as seen in CT scans. MATERIAL AND METHODS: This is an observational study including 63 patients (46 males and 17 females) within the age range of 2 to 72 years (average age 38.75) who were undergoing Para nasal sinuses CT scan with pre and post contrast scans (Non-ionic contrast media). Histopathology and treatment response was collected from patients documents and case papers. Descriptive statistics were used to summarize the data. RESULTS: The peak age incidence of Paranasal sinus lesions seen in age of 31-50 years, with 27 cases. Discharge is most common symptom seen in 44 cases (70%),obstruction in 19 cases (30%) and pain in 10 cases(17%). Most common sinus involved is maxillary sinus 49 cases (77%).According to pathology inflammatory lesions were the most frequent constituting 43 cases (63%) CONCLUSION: Computer tomography is a sensitive and noninvasive tool that allow rapid detection,localization and extent of lesions on which management and prognosis is based. Contrast enhancement CT is particularly useful in evaluating neoplastic, chronic and inflammatory process. Key Words: Contrast enhancement, Paranasal air space, Computerized axial tomography (CAT scan) X-ray computed tomography INTRODUCTION The Paranasal sinuses are hollow, air-filled spaces located within the bones of the Face and surrounding the nasal cavity, a system of air channels connecting the nose with the back of the throat. There are four pairs of sinuses, each connected to the nasal cavity by small openings. First modern and accurate descriptions of the Para nasal sinuses can be traced to the works of the late 19th century Austrian anatomist Emil Zuckerkandl. CT has become a useful diagnostic modality in the evaluation of the paranasal sinuses and an integral part of surgical planning. It is also used to create Intraoperative road maps and the radiologic examination of choice in evaluating the PNS of a patient with *Corresponding Author: Dr. Bhumikaben P Suthar* Address: 12/C Gurukirpa Society, Opposite Shayog, Refinery Road, Gorwa, Vadodara, Gujarat 390016. Contact number: +919426319976. Email: bhums22@yahoo.co.in sinusitis. The use of CT scanning combined with functional endoscopic sinus surgery (FESS) has empowered the modern sinus surgeon to treat patients more effectively, facilitating reduced morbidity and complications. Objective of study: Purpose of study of 63 patients using CT scan for space occupying lesions in Para nasal sinus is to establish diagnosis, localize the disease, characterize the extent of pathology and describe any anatomical variations, Find out incidence rate, age and sex distribution patterns, evaluate the nature and extent of the lesions this helps the surgeon to elucidate whether surgery has a role and the type of surgery to perform, Distinguish aggressive and non-aggressive lesions, find symptomatology of the lesions and modes of presentation. MATERIAL AND METHODS Selection Criteria: Patients were studied with computed tomography for space occupying lesions of the Para nasal sinuses. All patients were selected from the S.S.G Hospital of Vadodara and were scanned at on or other CT scanners in 75 Int J Res Med. 2015; 4(4);75-80 e ISSN:2320-2742 p ISSN: 2320-2734
Vadodara city. In study of Para nasal age-group of 11-30 years. Osseous, sinuses CT scan, all axial, coronal, sagittal Cartilaginous and Odontogenic lesions scans were done with pre and post contrast were seen in 00-60 years of age-group. scans. 5 mm contiguous sections taken Haemopoietic lesions were seen in older from hard palate to frontal sinuses. age-group of 41-50 years. Sex distribution: Histopathology study of biopsy specimen The study comprised of 46 males (i.e. or surgical specimen was done for 73%) and 17 females (i.e. 27%). The confirmation of the diagnosis. Where overall male to female ratio was 2.7:1. histo-pathological confirmation was not Symptomatology: Osseous, Cartilaginous possible, clinical response to treatment and Odontogenic lesions presented with were considered for the final diagnosis. obstruction, swelling and pain as major Technique of CT scan of PNS: Most of the symptoms. Discharge was the most patients were scanned on whole body CT common symptom seen in 44 cases (i.e. scanner from SIEMENS. Positioning of 70%) and obstruction in 19 cases (i.e. the patient: Scanning should cover the 30%). Pain was present in 10 cases(i.e. region from the anterior portion of the 17%). Bleeding was present in 4 cases (i.e. frontal sinus through sphenoid sinus and 7%) and in majority of the epithelial gantry angulations is perpendicular to the lesions. Proptosis was seen in 7 cases (i.e. bony palate with contiguous 3 to 5mm 12 %), majority being epithelial, slice thickness. The patient is imaged in neuroectodermal and soft tissue lesions. two positions prone and supine for axial Predominant Sinus Involved: According and coronal imaging respectively. For to standard classifications, lesions of axial images, the patient is seen supine and paranasal sinuses can be categorized under scan plane is drawn with the scan lines the following heads: Developmental, parallel to the infraorbital meatal line. For inflammatory and neoplastic. The most coronal imaging-the patient is prone with common sinus being involved is the the neck extended to the maximum maxillary sinus seen in 49 cases (i.e. 77%). possible, the scan plane is drawn with scan It was most commonly involved by lines to the hard palate as far as possible. inflammatory lesions seen in 35 cases, Intravenous contrast injection: For this followed by epithelial origin lesions in 5 study, non-ionic contrast media was cases. And including 2 cases of preferred because if gives fewer side neuroectodermal, 3 cases of soft tissue effects and better accepted by patients. origin and 4 cases of osseous, cartilaginous Dynamic study remains a useful technique. and dontogenic origin. Ethmoid sinuses A bolus of 40ml at rate of 0.8 to 1 ml/sec were affected in 23 cases (i.e. 36%) was given. predominantly, including 9 cases of RESULTS inflammatory origin, 5 cases of epithelial Demographic Profile: Disease profile in origin, 4 cases of neuroectodermal, 3 cases various age-groups: The study was carried of soft tissue origin and 2 cases of osseous, out on 63 patients, comprising of 46 males cartilaginous and odontogenic origin. and 17 females, between the age groups of Sphenoid sinuses were involved in 17 00-72 years. The age-wise distribution of cases (i.e. 26%). It was more commonly the patients included in this study is as involved by the lesions of inflammatory follows: The peak age incidence was that and neuroectodermal origin. Case of of 31-50 years, with 27 cases. The average haemopoietic origin, that is lymphoma, age of the cases was 38.75 years. predominantly affected the sphenoid sinus. Inflammatory lesions were common in all Frontal sinus was seen to be involved in 18 the age-groups, but most commonly seen cases (i.e. 28%), including 8 cases of in the age-group 31-40 years. Epithelial inflammatory origin, 3 cases of epithelial lesions were commonly seen in the agegroup origin, 3 cases of neuroectodermal, 2 cases of 31-61 and above. of soft tissue origin and 2 cases of osseous, Neuroectodermal and neural-origin lesions cartilaginous and odontogenic origin. Both were seen in 11-60 years of age-group. the cases of bony origin involved frontal Soft tissue lesions were seen in younger sinuses. 76 Int J Res Med. 2015; 4(4);75-80 e ISSN:2320-2742 p ISSN: 2320-2734
Contrast Enhancement: *Table1* Osteomeatal Complex Features: Table 1: Enhancing Characteristics of Different Pathologies Non-enhancing Homogenous Heterogeneous Intense vascular Inflammatory 00 33 01 00 Epithelial 00 01 04 00 Neuroectodemal Neural 00 01 01 01 Soft-tissue 00 01 00 02 Osseous Cartilaginous 03 00 02 00 Odontogenic Haemopoietic 00 01 00 00 Osteomeatal complex was destroyed in 12 cases (i.e.19%) and most of them were neoplastic lesions. It was blocked in 12 cases (i.e.19%), most of them being inflammatory lesions. It was widened in 8 cases (i.e. 6%), which is seen in the antrochoanal polyp extending into the nasal cavity. Erosion of the walls of the sinuses and surrounding structures: *table 2* extension into the surrounding organs and spaces: Table 2: Erosion of the walls of the sinuses and surrounding structures No. of cases (%) Maxillary sinus Anterior wall Medial wall Posterolateral wall 06 (9.5) 11 (17.6) 10 (15.8) Lamina papyracea 14 (22) Hard palate / 07 (11) Alveolar arch Cribriform plate 09 (14.2) Sella 02 (3) Epithelial lesions were more aggressive most commonly involving the orbital space and infratemporal fossa. Neuroectodermal neural lesions most commonly involved the intracranial region either primarily or secondarily; in 5 cases (i.e. 80%) of this group. Soft tissue lesions were seen to involve nasopharynx, infratemporal fossa and pterygopalatine fossa. Intraorbital region was involved in 10 cases (i.e. 15.9%). Pterygopalatine fossa was involved in 10 cases (i.e. 15.9%). Nasopharynx was involved in 10 cases (i.e. 15.9%). Infratemporal fossa was involved in 06 cases (i.e. 9.5%). Intracranial region was involved in 05 cases (i.e. 7.9%). Intraoral region was involved in 04 cases (i.e. 6.3%). Intraorbital region was most commonly involved in 23 cases (i.e. 46%) followed by infratemporal fossa in 18 cases (i.e. 36%). Final pathology-wise distribution of lesions: Out of 63 cases, inflammatory lesions were the most frequently occurring constituting total of 43 cases (i.e. 63.25%). In this category, polyps were the most common lesions, comprising of 29 cases (i.e. 46%) of the total. Epithelial lesions were the second most commonly occurring lesions constituting 7 cases (i.e. 11%). In this category, squamous cell carcinoma was the most common lesion comprising of 3 cases (i.e. 16%) of the total study. There were 4 cases (i.e. 6.3%) of neuroectodermal neural origin and 5 cases (i.e. 7.9%) of osseous, cartiligionous and odontogenic origin. There were 3 cases (i.e. 4.7%) of soft tissue origin lesions and 1 cases (i.e. 1.6%) of haemopoietic origin. DISCUSSION The computed tomographic scans of 63 patients who were found to have space occupying lesions of paranasal sinuses were analyzed and compare with previous study as per table -3. [1] *Table 3* CT scan findings in mucomycosis Table 3: Types of lesions Lesions Kelkar et al (n=57) Present study (n=63) Inflammatory 14(25%) 47 Lesions Epithelial Lesions + 18(31%) 7 salivary neuroectodermalneural 02(3.5%) 4 Soft Tissue 08(14%) 3 Bone/Cartilageneous 10(17%) 5 and odontogenic Developemental 04(7%) 0 Metastatic 01(1.7%) 0 Haemopoietic - 1 In our study, we encountered with 2 patients of mucomycosis. In our study, frontal sinus were most commonly involved in both cases as compared to other studies, ethmoid sinuses were commonly involved. Proptosis was seen in 77 Int J Res Med. 2015; 4(4);75-80 e ISSN:2320-2742 p ISSN: 2320-2734
half the patients as compared to 37% in compared to Miyaguchi et al in which 70 other study. Distribution of Patients with % patients presented with nasal Nasal Polyps Polyps were commonly obstruction. Neck swelling was the second encountered in our study and were most common symptom with 70% patients analyzed to find that most (23 out of 37) which is comparable to the above were unilateral with upper nasal cavity mentioned study. [5] Distribution of involvement as compared to antrochoanal malignant lesions according to origin [6] polyps observed by Schramm et al. [2] *Table 5* Tumor cell types *Figure 1* Wegner s Granulomatosis Table 5: Distribution of malignant Fig-1: Left Antrochoanal polyp lesions according to origin Coronal CT image in bone window settings showing homogenous soft tissue density in left maxillary sinus (*), trifoliate in shape, extending from antrum to choana with widening of the osteomeatal complex (arrow) In our study, there are two cases of Wegner s Granulomatosis seen in a 68 years and 49 yrs old male patients with most commonly typical destruction of the nasal septum and associated soft tissue lesion involving the nasal cavity and the maxillary sinuses. In the study by Michael et al, maxillary antrum was most commonly involved with obliteration of the antrum due to superimposed chronic bacterial sinusitis. [3] Proptosis: Proptosis was commonly encountered in our study various cases were analyzed 4 *Table 4* Symptoms of Maxillary Sinus Carcinoma Table 4 Proptosis encountered in the study Lloyd et al (n =33) Present study (n= 8) Mucocele 11(33%) 1 Osteoma 4(12%) 0 Fibrous dysplasia 1(3%) 1 Carcinoma 9(27%) 5(13%) Infection 7(21%) 1 Granuloma 1(3%) 0 Soft tissue - 1 The most common symptom was nasal obstruction (90% of the cases) as Lesions according to origin Dubey et al (n=18) Present study (n=15) Epithelial 11(61%) 5 Salivary gland 4(22%) 0 Neuroectodermalneural 1(5.5%) 4 Bone,cartilagneinous,odontogenic 1(5.5%) 5 Hemopoietic 1(5.5%) 1 In our study, squamous cell carcinoma constituted the major number of cases seen in 60% comparable with the study by Sisson et al (61%). Adenocarcinoma and neuroblastoma constitute 20% each in our study. [7] *Figures 2, 3* Neuroectodermal and Neural Lesions Fig-2: Malignant melanoma Coronal CT image in bone window shows a large lesion extending from right maxillary sinus into right ethmoid and sphenoid sinuses and the nasal cavity, destroying the medial wall of right maxillary sinus and the nasal septum. In coronal CT images in soft window settings, plain and contrast enhanced respectively the lesion appears ill-defined, with hyper-dense areas within and in homogenously enhancing on administration of contrast. 78 Int J Res Med. 2015; 4(4);75-80 e ISSN:2320-2742 p ISSN: 2320-2734
Fig-3: Primaryextracranial meningioma involving left maxillary sinus Axial and coronal contrast enhanced CT images in soft window settings show an ill-defined, homogenously enhancing mass lesion in left maxillary sinus with destruction of its walls (arrows). The osteo-meatal complex is destroyed with extension of the mass into the nasal cavity. The subcutaneous tissue overlying the mass appears thickened with fat stranding noted within In a study by Simon et al, 13 cases with esthesioneuroblastoma were analyzed, the age group was between 36-81 years of age and most of the lesions were advanced stage lesions with involvement of the paranasal sinuses, nasal cavity and beyond, with or without involvement of the intracranial cavity. In our study, we had one case of olfactory neuroblastoma with age of 52 years with involvement of nasal cavity, paranasal sinuses and intracranial cavity comparable with the above study. [8] In our study, we have two cases of meningioma, one case was of extracranial primary meningioma and another is of the extension of the intracranial meningioma. We have one case of aggressive pituitary adenoma, the lesion showing inhomogeneous enhancement on contrast administration and causing destruction of the floor of the Sella and extending to the sphenoid sinuses. Inverted Papilloma It commonly involves the nasal cavity, lateral wall of nose and ethmoid sinuses. Maxillary antrum being rarely involved according to the study conducted by Majumdar et al. [9] In our study, the cases of inverted papilloma involves the nasal cavity and the ethmoid sinus; with involvement of maxillary sinus comparable with the above study. Juvenile Angiofibroma In our study, we encountered with 3 cases of nasopharyngeal angiofibroma out of which two cases seen in young adolescent males characteristically involving the pterygopalatine fissure and the nasopharynx and secondarily invading the maxillary and ethmoid sinuses with intracranial extension with characteristic intense vascular enhancement on contrast administration. In a study by Gullane et al, 21 cases were studied; all were adolescent males, and the lesion showed intense enhancement. [10] Bone/ Cartilaginous and Odontogenic Lesions In this study, we had two cases of fibrous dysplasia, which was seen in 20 year old female patient and 9 yrs male patient who presented with facial asymmetry. There was diffuse involvement of the respective sinus bone. Lymphoma of Sinonasal Cavities In our study, there is one 44 year old male of T- cell type non-hodgkin s lymphoma involving the sphenoid sinus. In the study done by Nakamura et al, B-cell variety of non-hodgkin s lymphoma was found mainly in the maxillary sinus and T-cell lymphomas were found in the nasal cavity and the ethmoidal sinus. The prognosis of B-cell lymphoma was better than T-cell lymphoma. The lesions involved in age group of 36-87 years. [11] CONCLUSION The CT scan features and clinical history of 63 patients with space-occupying lesions of the paranasal sinuses were analyzed according to the characteristics, site and extent of the lesion. The maximum numbers of patients were between 31 50 years, with 12 cases (i.e. 24%). The male to female sex ratio was 2.7: 1. The most common symptoms were nasal obstruction and discharge in the inflammatory lesions and swelling in malignant lesions. The most common lesions were that of inflammatory origin constituting 43 cases (i.e. 44%), out of which 30 cases (i.e. 30%) were polyps. Maxillary sinus was the most commonly involved sinus. Both the inflammatory and epithelial origin lesions affected the maxillary sinus equally. The extension of 79 Int J Res Med. 2015; 4(4);75-80 e ISSN:2320-2742 p ISSN: 2320-2734
the lesions especially in the region like endoscopic sinus surgery. J Laryngol infratemporal fossa, pterygopalatine fossa, Otol. 1990; 104: 477-81. orbital cavity, oral cavity and intracranial 5. Miyaguchi M1, Sakai S, Mori N, cavity was easily made out with Kitaoku S.Symptoms in patients with combination of axial and coronal noncontrast maxillary sinus carcinoma.j Laryngol and contrast enhanced scans. Otol. 1990 Jul;104(7):557-9. These extensions were not made out on the 6. Dubey RB, Tara NP, SisodiyaKN. plain X-rays. In most of the cases, we were Computerised tomographic evaluation able to identify whether the lesion is of orbital lesions: Pictorial essay. benign or malignant, but the final Indian J Radiol Imaging 2003;13:261- diagnosis was made by histopathology. 70 Thus, Computed Tomography is the best 7. Sisson et al. Paranasal Sinus modality of investigation for the paranasal Malignancy: A Comprehensive sinuses. It gives the site of involvement, Update. Laryngoscope 2000; 99: 143- tissue characterization of the lesion and the 150. exact of the lesion on which management 8. Simon JH, Zhen W, McCulloch TM, and prognosis is based. Hoffman HT, Paulino AC, Mayr NA, REFERENCES Buatti JM.Esthesioneuroblastoma: the 1. Kelkar AA, Shetty DD, Rahalkar MD, University of Iowa experience 1978- Pande SA. Space occupying lesions of 1998.Laryngoscope. 2001 paranasal sinuses- A CT study. IJRI Mar;111(3):488-93. 1991; 1:47-50. 9. Majumdar et al: Inverted papilloma of 2. Schramm VL Jr. Inflammatory and nose. JLO; 64: 467-470. neoplastic masses of the nose and 10. Gullane C. Carcinoma of the axillary paranasal sinus in sinus. A correlation with clinical children.laryngoscope. 1979 course and orbital involvement. Dec;89:1887-97 1983:141-143. 3. Michaels L. Benign mucosal tumors of 11. Morinaka S, Nakamura H. the nose and paranasal sinuses. Semin Inflammatory cells in nasal mucosa Diagn Pathol 1996; 13: 113-17. and nasal polyps. Auris Nasus Larynx. 4. Lloyd GA. CT of paranasal sinuses: A 2000; 27: 59-64. study of a control series in relation to 80 Int J Res Med. 2015; 4(4);75-80 e ISSN:2320-2742 p ISSN: 2320-2734