immunoglobulin g4-related sclerosing disease ( igg4-sd ) is a recently designated benign clinical entity that is histopathologically characterized by sclerosing inflammation and infiltration of numerous igg4-positive plasma cells affecting multiple organs ( 1 ) . igg4-sd of the head and neck region was previously known as chronic sclerosing sialadenitis ( kttner tumor ) or mikulicz 's disease that involves mainly salivary and lacrimal glands ( 2 ) . immunoglobulin g4-related sclerosing disease with involvement of palatine tonsils was reported in an earlier case study ( 3 ) . however , to our knowledge , the imaging findings of this rare manifestation are unreported in the literature . herein , we reported a case of igg4-sd involving palatine tonsils , with computed tomography ( ct ) and magnetic resonance imaging ( mri ) . this study was approved by the institutional review board of our hospital . the requirement for patient informed consent physical examination revealed enlargement of bilateral palatine tonsils with a lobulated mass - like lesion and ulceration in the right tonsil . the laboratory tests at presentation showed upper - normal range of leukocytosis ( 9990/ul ) with slightly increased neutrophil percentage ( 77% ) and elevated c - reactive protein value ( 81.0 mg / l ) . contrast - enhanced neck ct with a 64-row mdct ( sensation 64 , siemens medical solutions , malvern , pa , usa ) and mri with a 3.0 tesla mr scanner ( skyra , siemens medical solutions , erlangen , germany ) showed diffuse enlargement of both palatine tonsils and homogenous contrast enhancement . both palatine tonsils showed a striated pattern on the fat suppressed t2-weighted image ( fig . f - fluorodeoxyglucose positron emission tomography ( pet)-ct showed increased uptake at both palatine tonsils with maximum standardized uptake value of 7.9 . on pet - ct , no abnormal findings were found in other organs . considering the clinical and radiological findings , malignancy such as lymphoma or squamous cell carcinoma of right palatine tonsil associated with underlying bilateral tonsillar hypertrophy was initially suspected . the lesion was diagnosed as igg4-sd on subsequent excisional biopsy of the ulcerated mass - like lesion in the right palatine tonsil . histological examination showed dense infiltration of plasma cells with storiform - type fibrosis ( igg4 positive cells > 50/high power field ) , and a ratio of igg4-expressing to total igg - expressing cells of > 40% on immunohistochemistry ( fig . the patient was treated with corticosteroid therapy , which resulted in marked improvement of swelling of bilateral palatine tonsils within 1 month . follow - up ct taken 7 weeks after initial ct revealed improvement of bilateral tonsillar hypertrophy . the association of igg4 with sclerosing diseases was firstly described in 2001 by hamano et al . ( 4 ) , who reported an elevated serum igg4 level in patients with autoimmune pancreatitis . since 2003 , extra - pancreatic manifestations have been reported and the disease has been recognized as a systemic disease ( 567891011 ) . elevated serum igg and igg4 levels and the presence of autoantibodies ( e.g. , rheumatoid factor , antinuclear antibodies ) may help in the diagnosis of igg4-sd . histologically , igg4-sd is characterized by abundant infiltration of igg4-positive plasma cells , storiform fibrosis , obliterative phlebitis , mild to moderate eosinophilia , and increased number of igg4-positive cells on immunohistochemical staining ( 567 ) . recently , khurram et al . ( 3 ) reported a case of igg4-sd involving skin , tongue , and palatine tonsil . however , they focused on tongue lesions rather than tonsillar lesions and detailed imaging findings were not described . according to previous reports , ct and mri findings of igg4-sd are usually nonspecific . igg4-sd of the head and neck areas most commonly involves the salivary glands and lacrimal glands ; furthermore , cross - sectional imaging usually shows bilateral symmetric swelling of the involved glands with homogeneous enhancement . in our case , imaging findings of igg4-sd with tonsillar involvement were also nonspecific , but consistent with igg4-sd involving other organs , with bilateral swelling and focal bulging of palatine tonsil . although igg4-sd often has nonspecific imaging findings and is difficult to differentiate from other disease with imaging alone , the radiologist should include this disease in the differential diagnoses in an appropriate clinical setting because the disease responds well to corticosteroid therapy . patients with igg4-sd of palatine tonsil show clinical symptoms such as sore throat and swelling of bilateral tonsils , which are persistent despite antibiotics and analgesics . diffuse bilateral enlargement of submandibular gland or lacrimal gland are suggestive of systemic igg4-sd , because igg4-sd commonly involves multiple organs . in summary , we presented a case of igg4-sd involving palatine tonsils with a review of its ct and mri features . as seen in this case report , the imaging features of igg4-sd in the palatine tonsils are nonspecific , but compatible with known imaging findings of igg4-sd involving other organs . the radiologist should include igg4-sd in the differential diagnoses and recommend that clinicians check serum igg and igg4 levels in patients with bilateral tonsillar hypertrophy and persistent clinical symptoms despite medication .
immunoglobulin g4-related sclerosing disease ( igg4-sd ) is currently recognized as a distinct systemic disease involving various organs . 
 we reported the imaging findings of a case of pathologically confirmed igg4-sd involving bilateral palatine tonsils . 
 ct and mri showed diffuse enlargement of both palatine tonsils with homogeneous contrast enhancement . 
 focal contour bulging was noted in the right palatine tonsil . 
 lesions appeared as isointense on t1-weighted and slightly hyperintense on t2-weighted mri images , as compared with muscle . 
 the t2-weighted mri image showed a striated pattern in both tonsils . despite its rare occurrence 
 , igg4-sd should be included in the differential diagnoses of patients with symptomatic bilateral tonsillar hypertrophy that is non - responsive to medication .