Autoimmune pancreatitis‐associated prostatitis: Distinct clinicopathological entity

Abstract

Autoimmune pancreatitis (AIP) has been recently proposed as a disease entity, and an elevated serum IgG4 level is a characteristic finding in it. This disease is sometimes associated with other inflammatory diseases, such as retroperitoneal fibrosis and sclerosing cholangitis. To elucidate the clinicopathological characteristics of AIP-associated prostatitis (AIP-P), the clinicopathological findings of AIP-P patients were evaluated, and the immunohistochemical expression of the IgG subclasses (IgG1, IgG2, IgG3, and IgG4) in six AIP-P patients was compared with that in 10 control patients who were clinically diagnosed as suspicious for carcinoma but who had focal inflammation without adenocarcinoma on histological examination of the prostate. All AIP-P patients had the characteristic findings of AIP, and their lower urinary tract symptoms (LUTS) improved after steroid therapy. In four of five AIP-P patients, digital rectal examination indicated prostate enlargement. Histologically, AIP-P had lymphoplasmacytic and scattered eosinophilic infiltration and obliterative phlebitis accompanying gland atrophy with dense fibrosis. Immunohistochemically, the IgG4-positive plasma cell/mononuclear cell ratio was significantly higher in the AIP-P group than in the control group (P = 0.0011). AIP-P is a distinct clinicopathological entity, and a mechanism similar to that implicated in AIP may be involved in it as well.

A Case of IgG4-Related Retroperitoneal Fibrosis from the Renal Pelvis Mimicking Bilateral Hydronephrosis

“…This disease has only been recently proposed and is considered to involve systemic inflammatory fibrosis, including retroperitoneal fibrosis, autoimmune pancreatitis, chronic sclerosing sialadenitis and sclerosing cholangitis [1,2,3,4,5]. Herein, we report a patient presenting with hydronephrosis-like manifestations due to a renal pelvic mass secondary to IgG4-RD.…”

IgG4-Related Skin Disease, a Mimic of Angiolymphoid Hyperplasia with Eosinophilia

“…IgG4-related lesions have been further identified in other reports in such locations as the salivary gland [9], the lacrimal gland [10], the ocular adnexa [3], the pituitary gland [11], the pleura [12], the lung (interstitial pneumonia or inflammatory pseudotumor) [13], the breast (inflammatory pseudotumor) [14], the mediastinum (mediastinal fibrosis) [15], the pancreas (autoimmune pancreatitis) [16], the gallbladder [17], the bile duct [18], the liver (inflammatory pseudotumor) [19], the prostate [20,21], the retroperitoneum (retroperitoneal fibrosis) [22,23], the kidney (tubulointerstitial nephritis) [24], the aorta/artery (inflammatory abdominal aortic aneurysm) [25,26], the paravertebral area [27], the meninges [28], and the systemic lymph nodes (lymphadenopathy) [29]. Thus, it is likely that almost all organs can be affected in the IgG4-related diseases.…”

Radiologic Findings of IgG4-Related Disease

“…Many authors have reported extra-pancreatic lesions associated with AIP, such as lachrymal and salivary [22,64], lung [26,27,[65][66][67][68], mediastinal [25], bile duct [8,28,69], renal [34,35,70,71], retroperitoneal [12] and prostatic [36][37][38] lesions. Recently, the concept of 'IgG4-related diseases' has been proposed because pathological findings similar to those of pancreatic lesion, more specifically infiltration of IgG4-bearing plasma cells, lymphocyte and fibrosis, were found in these extra-pancreatic lesions [2,12,22,33,[39][40][41][42].…”

“…In addition, a variety of extra-pancreatic lesions, such as lachrymal and salivary gland lesions [22][23][24], hilar lymphadenopathy [24,25], interstitial pneumonia [24,26,27], sclerosing cholangitis [2,8,24,[28][29][30], retroperitoneal fibrosis [12,24,29,[31][32][33], renal lesions [24,34,35], and prostatic lesions [24,[36][37][38] have been reported to be complicated with AIP. Extra-pancreatic lesions show systemic distribution and share similar pathological and clinical findings with AIP, such as storiform fibrosis, prominent lymphoplasmacytic infiltration and abundant IgG4-bearing plasma cells [12,22,25,33], and have a favorable response to corticosteroid therapy [3, 4, 13-15, 22, 28-30].…”