Dr. Harsha K J 3 rd yr Resident, Dept of Radiodiagnosis, Medical college, Baroda.

1. CASES Dr. Harsha K J 3rd yr Resident, Dept of Radiodiagnosis, Medical college, Baroda.

2. CASE 1

5. D/D • Mucocele • Inverted papilloma • Silent sinus syndrome • Hypoplastic maxillary sinus • Polyposis

6. Mucocele • Inverted papilloma • Silent sinus syndrome • Hypoplastic maxillary sinus • Polyposis

7. Mucocele • An accumulation of secretion products, desquamation, and inflammation within a paranasal sinus with expansion of its bony walls. • The lesion is limited by a wall (“sac”) made by respiratory mucosa with a pseudostratified columnar epithelium. • 89%  located in the fronto-ethmoid area, • while maxillary, ethmoid and sphenoid mucoceles  rarely observed.

8. sinus ostium blockage • 4 – 5 th decade • M = F accumulation of mucus creates a positive pressure inside the cavity Resorption of the surrounding bony walls Remodeling and/or erosion of the surrounding bone

9. Sinus ostia obstruction may be the consequence of • chronic rhinosinusitis, • allergic rhinitis, • previous radiotherapy, • trauma, • scarring due to previous surgical procedures, • more rarely, of sinonasal neoplasms.

10. Imaging plays a crucial role in defining the deep extension of mucoceles, particularly towards three important areas, • orbit, • anterior cranial fossa (up to 20%), • optic nerve canal. • Bulging of bony walls is the most typical presentation of mucocele

11. Frontal sinus is expanded and remodeled, its floor is completely demineralized (white arrows). Inferolateral displacement of the ocular bulb can be observed. Retained secretions within sinuscavity (b) exhibit rather high density, refl ecting desiccation. Scans acquired at the level of middle meatus (c) demonstrate anethmoidal lesion destroying the medial orbital wall, nasal septum and ethmoid fovea (black arrows). The lesion impairs mucus drainage in the middle meatus and is, therefore, responsible for mucocele formation

12. After contrast administration, enhancement is observed exclusively at the periphery, along the thin mucosal layer, both at CT and MR. • Maxillary sinus mucoceles were related to stenosis/occlusion of the ethmoid infundibulum because of uncinate process fragments or scar tissue. • Besides, mucoceles of the maxillary sinus may develop after Caldwell-Luc procedures due to the entrapment of mucosa

13. Absent or exclusively peripheral contrast uptake enables one to predict mucocele

15. In our case, there is no bony expansion, instead there is bony retraction, hence mucocele is ruledout.

16. Inverted papilloma • Mucocele • Silent sinus syndrome • Hypoplastic maxillary sinus • Polyposis

17. Inverted papilloma • is an epithelial benign neoplasm composed of invaginating crypts, thick ribbons or islands of non-keratinizing squamous epithelium which may alternate with or be covered by pseudostratified columnar (cylindrical) or ciliated respiratory epithelium. • M : F = 5 : 1 • 5 – 6th decade, although occasionally observed in pediatric age group also • human papilloma virus

18. lateral wall of the nasal fossa and the maxillary sinus are the most frequent sites of origin of inverted papilloma. • inverted papilloma could easily extend through sinus ostia to the surrounding cavities without destroying the bony walls. • Intracranial invasion is a rare event, mostly noted in lesions recurring at the level of the cribriform plate or ethmoid roof. • Intraorbital extension may be observed in lesions with extensive ethmoid involvement; however, the tumor usually laterally displaces the orbital content without transgressing the periorbit. • is generally unilateral

19. IMAGING FINDINGS • site of origin, • the pattern of changes of the lateral nasal wall framework. • the lobulated surface contour on CT and the striated inner pattern on MR. • On CT, high densities within the inverted papilloma are shown in up to 50% of cases

20. The peculiar macroscopic arrangement of inverted papilloma is characterized by the alternation of quiteregular parallel folds made of a highly cellular metaplastic epithelium and of an underlying less cellular stroma. • On CT examination, when surrounded by air, these folds give inverted papilloma its typical lobulated contour

21. MR does more, because the inner macroscopic arrangement is demonstrated as a septate striated pattern or a convoluted cerebriform pattern both on T2 and contrast-enhanced T1. • Thus, on T2 these parallel folds of inverted papilloma appear as thick striations of hyperintense signal alternate with thinner ones, closer to fat intensity.

22. Striated inner pattern of inverted papilloma on MR. Plain (a) and enhanced (b) axial SE T1, TSE T2 (c) and enhanced SE T1 (d) on the coronal plane. The alternation of quite regular parallel folds is detectable on all sequences (arrows). Displacement and remodeling of the posterolateral maxillary sinusal wall is shown (arrowheads) a b

23. At (long arrows) fi lls the superior meatus, and abuts the ground lamella of the middle turbinate that shows irregular sclerotic changes (short arrows

24. Inverted papilloma of left posterior ethmoid sinus. At CT, the lesion extends into both sphenoid sinuses. Lobulated contours are well detectable on bone-window image (a,b). Non-homogeneous density and irregular bone densities are more evident on soft-tissue windows (c,d)

25. At CT, a maxillary sinus inverted Papilloma fills the whole paranasal cavity and displaces all sinusal walls. Focal remodeling and thinning of the posterior aspect of medial sinus wall is seen (arrows), suggesting the extent through the posterior fontanelle area, a path of lesser resistance

26. On contrast-enhanced T1, the stroma shows a strong enhancement while the thinner epithelium has a lesser enhancement.

27. Inverted papilloma arising from the left middle turbinate, SE T1 enhanced sagittal (a), axial (b), and coronal (c) planes. a Because the path of least resistance is on the sagittal plane, the striated parallel septations turn into a fan-like patter detectable on the sagittal SE T1 enhanced image (arrows). b The lesion extends into the ethmoid infundibulum and protrudes into the maxillary sinus (short arrow). Posteriorly it projects through the choana (arrowheads). Uncinate proces (long arrow). c On the coronal plane, the striated appearance results from the parallel orientation of the septa (black arrows). Integrity of left lamina papyracea/periorbita is shown (white arrows)

28. Coronal and axial TSE T2 images show that only the small portion of the inverted papilloma protruding into the middle (MM) and inferior (IM) meati is actually demonstrated by endoscopy – arrowheads point to the inferior turbinate (b). Within the maxillary sinus, the main part appears hypointense compared with the bright signal of the thickened mucosa. NLD, nasolacrimal duct; UP, uncinate process; MT, middle turbinate; IT, inferior turbinate; NS, nasal septum

29. Polyposis • Mucocele • Inverted papilloma • Silent sinus syndrome • Hypoplastic maxillary sinus

30. Polyposis

31. Ostiomeatal unit pattern reflects the obstruction of all drainage systems in the middle meatus. • Nonspecific mucosal thickenings as well as maxillary, frontal, and anterior ethmoid sinusitis, nasal polyps most commonly induce ostiomeatal unit pattern. • Marked septal deviation and concha bullosa are anatomic predisposing factors.

32. Polypoid thickening of the mucosa in the middle meatus (asterisk). Retained secretions fill the maxillary sinus; mucosal thickenings in the anterior ethmoid. Incomplete resorption of the uncinate process, only partially visible (arrows)

33. 1) Widening of ethmoid infundibulum can be observed in several different conditions, including antrochoanal polyp and inverted papilloma. The specificity of this finding, however, is increased by bilateral presentation. • 2) Truncation of middle turbinate (bilateral in upto 80% of cases)

34. Antrochoanal polyp. Axial (a) and coronal (b) CT scan. Polypoid lesion occupies the left maxillary sinus, Protruding into the nasal fossa and, through the choana, in the nasopharynx (arrows). Note in (b) the low density of the lesion

35. Hypoplastic maxillary sinus • Mucocele • Inverted papilloma • Silent sinus syndrome • Polyposis

36. Hypoplastic maxillary sinus

37. B/L • Maxillary sinus hypoplasia occurs more frequently in syndromes of craniosynostosis, osteodysplasia (Melnick-Needles), as well as in cases of Down's syndrome (hypoplasia of the frontal sinus). • It is also seen in the cases of thalassemia major when the demand for marrow prohibits sinus pneumatization. • Conditions like severe infection, trauma, tumor, irradiation, and congenital first arch syndrome, arrest the growth of the maxilla resulting in a small (hypoplastic) antrum.

38. CT scan PNS coronal and Axillary views showing B/L hypoplastic maxillary antra.

39. Silent sinus syndrome • Mucocele • Inverted papilloma • Polyposis • Hypoplastic sinus syndrome

40. Silent sinus syndrome

41. characterized by volume loss of the maxillary sinus after infundibular occlusion. • 3 – 5th decade • presents with painless enophthalmos, facial asymmetry, and/or diplopia. • Rarely do patients complain of symptoms of sinusitis.

42. Imaging findings of silent sinus syndrome are characteristic. • There is maxillary sinus volume loss with inward retraction of the sinus walls and sinus opacification. • The ethmoidal infundibulum is occluded, usually due to opposition of the uncinate process against the inferomedial orbit. • The sinus volume loss accounts for the corresponding increase in ipsilateral orbital volume and size of the middle meatus.

43. Two coronal CT images demonstrate right maxillary sinus volume loss when compared to the left. There is inward retraction of the sinus walls (red arrows) , increase in the sizeof the middle meatus (green arrows) There is lateralization of the uncinate process and middle turbinate. This patient had concomitant right ethmoid air cell and frontal sinus opacification.

44. expansion of the retroantral fat

45. Silent sinus syndrome, or maxillary sinus atelectasis

46. Treatment is aimed at creating an outlet for obstructed mucous via a nasal antral window or maxillary antrostomy. • The goal of surgery is to prevent disease progression and further deformity.

47. Mucocele Polyposis SICK SINUS SYNDROME Hypoplastic maxillary sinus Inverted papilloma • Expansion of sinus • Infundibular block • No enhancement/ • Peripheral mucosal enhancement • Widening of ethmoid Infundibulum • B/L • Truncation of middle Meatus • Expansion of sinuses maxillary sinus volume loss with inward retraction of the sinus walls and sinus opacification. increase in ipsilateral orbital volume & size of the middle meatus Contrast enhancement convoluted cerebriform pattern both on T2 & contrast-enhanced T1 B/L Syndromic Small sinuses

48. CASE 2

49. Axial contrast enhanced CT images in the pancreatic parencymal phase demonstrate homogenous enhancement with loss of the normal pancreatic lobulations with a rim of hypoattenuating soft tissue (red arrows). Minimal stranding of the fat around the pancreatic tail  (orange arrows) is seen. Mild intrahepatic biliary ductal dilatation is present (green arrows), however no pancreatic ductal dilatation is present.

50. AUTOIMMUNE PANCREATITIS