CASES

1. CASES Dr. Mayur Pankhania, R1 Dept. of Radiodiagnosis SSG Hospital (11/4/07 )

2. CASE 1

3. History • 34yr male presented with a swelling around angle of mandible and was tested positive for HIV Infection.

6. Imaging Finding • Axial US images show multiple hypo to anechoic well defined cystic lesions of varying size noted within parotid gland with enlarged parotid gland enlargement. Axial US image at the level of upper jugular vein shows well defined hypoechoic lesion at s/o enlarged level 2 lymph node. • Axial CECT at the level of angle of mandible shows enlarged both parotid gland with low attenuating fluid density lesions of variable size s/o Cystic replacement of the parotid glands without evidence of solid enhancing component or periglandular inflammation. Borderline enlarged Level 2 cervical lymph nodes.

7. D/D Lymphoepithelial cyst Warthin's tumors. Cystic pleomorphic adenomas. Low grade Mucoepidermoid Carcinoma. Tuberculosis

8. WARTHIN'S TUMORS • Most common bilateral benign neoplasm of the parotid gland with mean age of presentation is > 50yr with male (Smokers) predominance. • 10% cases shows bilaterally and multicentricity • It represent heterotopic salivary gland epithelial tissue trapped within intraparotid lymph nodes. • Malignant transformation and Facial nerve involvement is rare • multiplicity and location at the tail of the parotid gland (near the lower mandible) are typical features of this tumor

9. Imaging Finding : • CT • well defined, small, ovoid smoothly marginated homogenous soft tissue density masses occurs usually on posterior aspect of the parotid glands.  • They tend to have multiple lobules.  • Less than 10% have calcifications.  • MRI • On T1 weighted, focal area of high signal intensity • On T2 weighted, intermediate signal intensity due to predominant epithelial components and high signal due to cystic and lymphoid proliferation.

10. Axial CECT at level of mandible shows large, well defined smoothly marginated bilateral heterogeneous masses in the parotid glands with significant cystic component and shows faint enhancement. The right parotid gland also shows calcification within.

11. MR images (a)Axial T2 W image shows large, lobulated intermediate intense mass lesion in deep lobe. there is well defined High-intensity region noted within it s/o proteinaceous cysts (arrow) in tumor mass .(b).Axial T1 W image shows lobulated, intermediate-intensity mass in superficial lobe of parotid gland s/o warthins tumor. Facial nerve (arrow) is seen proximally.

12. PLEOMORPHIC ADENOMA • Also known as a benign mixed tumors, are the most common epithelial salivary tumors and comprise almost 80% of parotid neoplasm. • This tumortypically manifests as a hard, painless, slow-growing mass, typically arise in the superficial lobe of parotid gland. • More common in a older children and young adults, with female predominance. • As the alternate term mixed tumorimplies, architectural heterogeneity is the dominant histologicfeature of pleomorphic adenomas.

13. USG: Longitudinal section through the left parotid gland demonstrates a slightly hypoechoic to anechoic lobulated mass in the superficial lobe of the gland distorting the capsule. There is associated distal acoustic enhancement. Note marked heterogenecity of internal architecture. s/o cystic pleomorphic adenoma.(The mandible is indicated by arrowheads. They can have cystic areas & small calcification within them)

14. CT and MR imagingfindings in pleomorphic adenoma vary depending on tumor size. • Smaller tumors are more homogeneous and well-defined, whereaslarger tumors are often less well-defined and more heterogeneouswith areas of necrosis or hemorrhage. • Pleomorphic adenomas mildlyenhance after intravenous administration of contrast material.

15. The MRI features of pleomorphic adenoma are nonspecific. • Smaller tumors typically demonstrate tend to be well defined, hypointense on T1-weighted images, and markedly hyperintense on T2-weighted images. • larger tumors are more heterogeneous and demonstratelow to intermediate signal intensity on T1-weighted images andintermediate to high signal intensity on T2-weightedimages. T1W T2W

16. MR images (a) Axial T1 W image shows a homogeneous intensity, well-circumscribed mass lesion at junction of superficial and deep lobes of right parotid gland. (b) Image obtained at axial level 1.4 cm superior( cranial ) to that, shows facial nerve coursing superior and lateral to tumor (arrowheads).

17. MUCOEPIDERMOID CARCINOMA • most common malignant salivarygland neoplasm in children. • Theyare histological classified as low-, intermediate-, or high-grade. CT : • Low grade ca shows cysticlow-attenuation areas and, rarely, focal calcifications. • High-grade mucoepidermoid carcinomas tend to be more solid withfewer cystic areas and are more homogeneous at both CT and MRimaging. MR : • Low-grademucoepidermoid carcinomas are hypointense to isointense withT1 weighted MR sequences and hyperintense with T2 sequences.

18. Longitudinal ultrasound of the left parotid gland shows a poorly defined mass with smooth, "benign-appearing"margins, in the superficial lobe with heterogeneous internal architecture. In a c/o Low-grade Mucoepidermoid carcinoma. Note extension of tumor superficially through the parotid capsule (arrow).

19. Axial contrast enhanced fat saturated T1 W MR image shows ill-defined enhancing mass lesion (arrow) with fuzzy margins , involving junction of deep and sup. Lobe of rt parotid gland. On T2 W MR images it shows a heterogenous intermediate-signal-intensity mass lesion (arrow). Which is slightly lower in intensity than that of the normal parotid tissue In a c/o high-grade mucoepidermoid carcinoma

20. TUBERCULOSIS • It is more commonlyseen secondary to systemic dissemination of pulmonary TB than as primary extrapulmonary TB. • If the salivaryglands are primarily affected, the parotid gland is involved70% of the time. Imaging findings:- • bacterial parotitis, and • necrotic nodes or focal abscessestend to develop within the gland. • multiple enlarged bilateral neck lymph nodes with calcification.

21. Axial CECT scan at the level of mandible shows enlarged both parotid gland with heterogeneous echotexture. There is focal hypodence lesion with surrounded by thick enhanced rim s/o abscess formation in c/o TB infection of Parotid gland

22. LYMPHOEPITHELIAL CYSTS • Pt with HIV may present with parotid gland enlargement due to lymphocytic infiltration and lymphoepithelial cysts. • Parotid gland enlargement is often associated with diffuse cervical adenopathy. • The cysts are painless and slow growing, with predominantly bilateral involvement. Lesions are usually multicystic with superficial involvement.

23. Etiology:-of these cysts remains unclear. They may represent cysts of epithelial elements, trapped within parotid lymph nodes during embryogenesis, as seen in cases Warthin tumor. Alternatively, these cysts may be the result of partial obstruction of the terminal ducts by the surrounding lymphocytic infiltrations (which is more commonly infected by HIV). Because of this, HIV testing should be performed if a patient presents with lymphoepithelial cysts, which occur exclusively in the parotid glands.

24. US : • Two US patterns of parotid involvement in HIV infection havebeen described. • In approximately 70% of patients, multiple hypoechoicor anechoic areas without posterior acoustic enhancement areseen. • In the remaining 30% of patients, anechoicfoci are seen and are believed to represent lymphoepithelialcysts. CT / MR : • At cross-sectional imaging, demonstrate bilateral parotidgland enlargement with intraglandular cystic and the cysts are multiple, bilateral, and of varying size and are easily visualized in a contrast-enhanced gland parenchyma. • Cervical adenopathy is typically seen, and enlargedadenoids may also be present.

25. Axial US images show multiple hypo to anechoic well defined cystic lesions of varying size without posterior enhancement noted within enlarged parotid gland s/o lymphoepithelial cyst. Axial US image at the level of upper jugular vein shows well defined hypoechoic lesion at s/o enlarged level 2 lymph node. a C/O HIV parotitis

26. Axial CECT scan demonstrates multiple low attenuating fluid density lesion s/o cysts with thin rims of enhancement present in the superficial and deep portions of the left gland. Similar cysts of varying sizes are present in the right gland. A scan more caudally shows multiple cysts in the tails of both parotid glands. Multiple homogeneous lymph nodes are present in the submandibular and posterior triangles bilaterally.

27. Axial post Gd T1W MR image shows well defined hypointense lesions involving both parotid gland which shows hyperintense on T2-weighted images. s/o multiple cysts (arrowheads) within the parotid glands. Cervical lymphadenopathy (arrows) is also noted. T2W IMAGE POST Gd T1W

28. CYSTIC LESIONS OF PAROTID GLAND ABSCESS MALIGNANT BENIGN • Rim enhancement. • also look for calculi. • USG guided aspiration -Irregularly marginated -heterogenous -surrounding structure invasion -vascular involvement -cervical lymph node Well defined Homogenous HIV INFECTION Pleomorphic adenoma Warthin’s tumor lymphoepithelial cyst Mucoepidermoid ca. • young adults • and old childrens • parotid gland MC • biopsy >50yr B/L 2nd MC Multiplicity & involvement of tail. Cervical lymphadenopathy on US Cyst shows no enhancement

29. CASE 2

30. History • 20-year-old female presented with painless palpable left frontal scalp mass and occasional chronic headache.

32. Coronal bone window image of ct head

33. Unenhanced and contrast enhanced T1-weighted coronal MR Images

34. Imaging Finding :- Frontal skull radiographs show slightly expansile lytic lesion with sclerotic margins in left frontal bone. Coronal CT scan (bone algorithm) shows well defined lesion confirm to diploe space , coarse trabecuiae within lesion and sclerotic margins. Involvement of outer skull table is noted. MR Images, T1W MR images shows a para sagittal lesion appears iso to hypo intense compare to diploe bone marrow surrounded by thick hypo intense rim s/o sclerosis and on giving contrast, lesion appears homogenous and well enhancing with surrounding hypointense rim and lesion is seen to extends across mIdline but does, not Involve superior sagittal sinus.

35. D/D • Hemangiomas • Eosinophilic Granuloma • Osteoma • Epidermoid and Dermoid Cyst • FD • Meningioma • Metastasis

36. Axial CT scan shows oval or round isolated lytic lesion with well circumscribe margin and beveled edges that contains bony sequestrum. Lesion is involve the full thickness of the calvarium. Typical c/o Eosinophilic Granuloma EOSINOPHILIC GRANULOMA (LANGERHANS CELL HISTIOCYTOSIS)

37. Axial T2-weighted MR image shows bright signal intensity of lesion involving the high parital region on left side which on T1 W MR post Gd image shows well enhancement with lack of enhancement of bony sequestration. Adjacent dura shows enhance. s/o dural involvement. A c/o EG

38. Axial CT scan shows well defined lobulated sclerotic lesion arising form outer table of left parital bone.A c/o outer table Osteoma. OSTEOMA most common benign tumors of the calvarium

39. A, Axial CT scan shows well defined mass density lesion with lobulated margins involving high parital region on left side.B, Axial T2-weighted image shows signal void in lesion (arrow). A c/o Inner table osteomas (some time it can be misdiagnosed as ossified Meningioma. Unlike meningioma, osteomas show signal void and an absence of soft-tissue component on all MR imaging sequences)

40. CT scan shows well-defined lytic, lesion with sclerotic margins causing expansion of outer and inner table of skull. c/o Epidermoid cyst in frontal bone. EPIDERMOID Epidermal inclusion cysts are mainly located around the midline, but any bone in the cranial vault can be involved. Pressure erosion causes remodeling and expansion of the outer and inner tables. The lesion is typically lytic and oval-shaped with a clearly sclerotic Margin.

41. Sagittal T1-weighted MR image shows homogeneous low signal intensity lesion in frontal region which causes involvement of inner table and scalloping of outer table of skull, which on T2 W fat saturation images shows well-defined, hyperintense cystic lesion, indicating fluid-filled lesion (arrow). (but signal intensity varies depending on the lipid content or hemorrhagic products) c/o Epidermoid cyst in frontal bone

42. DERMOID TUMORS axial CT scan shows well defined soft tissue density lesion noted in the medline occipital region, involving outer table and causing scalloping of inner table. With foci of air bubble within it s/o dermord cyst with dermal sinus. Dermoid tumors are the largest group of pediatric tumorswith intracranial extension Dermoid cysts contain elements of dermal and epidermal origin. These cysts are predominately located periorbitally and in the posterior fontanelle or occipital midline, with or without including the dermal sinus

43. On MRI images: • T2-weighted images as areas of hyperintensity replacing the normal diploetic space and cortical bone. • Gadolinium-enhanced Ti-weighted images usually show marked enhancement • Rarely, a focal lesion may be due to a plasmacytoma. These lesions have marked enhancement of the soft-tissue component after contrast agent administration.

44. METASTASIS Axial CT scan shows well-defined lytic lesion, with ragged margins or permeative destruction. soft-tissue mass noted surrounding lytic area is a characteristically present. A c/o mets from hepatocellular carcinoma. (Exceptions to this rule include prostate and breast tumors, which often show osteoblastic reaction (but with less )hyperostosis than meningiomas.) Most multiple abnormal radiolucencies in the calvarium after the fifth decade of life are carcinoma metastases.

45. Axial gadolinium-enhanced Ti-weighted MR image shows marked enhancement with delimitation of intracranial and extracranial soft tissues in the high parotal region in a c/o metastasis.

46. MENINGIOMA • Meningiomas are the most common nonglial intracranial tumors and typically produce localized hyperostosis( osteoblastic) of adjacent bone. • An osteoblastic reaction is commonly seen. Less commonly, mixed blastic and lytic reactions are present. • Purely lytic reactions are extremely rare and are more aggressive. • Primary intraosseous meningioma is also uncommon and has imaging features similar to those of intracranial meningioma. • The hallmark of the differential diagnosis of intraosseous meningioma is the bone-centered soft-tissue component depicted on MR imaging.

47. Axial CT scan shows there is focal expansion of right frontal diploe space with sclerosis and hyperostosis and irregularities of inner table noted. A c/o frontal-bone meningioma.

48. Coronal CT scan shows both lytic and blastic bone reaction ininvolving the vertex with soft-tissue component.Coronal T1-weighted MR image shows soft-tissue mass on both sides of calvarium. A hallmark for intraosseous meningioma.

49. FIBROUS DYSPLASIA CT scan shows ground-glass lesion with well defined margins. there is expansion of the diploe with bulging of the outer table and thinning and erosion of the inner table, which characteristically does not protrude inwardly. A c/o occipital FD Thickening and increased density of the normal bone is present at the margins This variety is most common type of FD most frequently seen in childhood and adolescence. The skull is involvedin both the monostotic and polyostotic form of the disease.

50. MR imaging shows decreased signal on all pulse sequences with occasional hyperintense areas and also reveals absence of soft tissue, a cardinal difference from other sclerotic lesions. Axial proton density-weighted MR image shows heterogeneous signal intensity of lesion. s/o fibrous dysplasia of occipital bone.