Mass-forming Lesions Research Articles

Contrast-enhanced ultrasound complements two-dimensional ultrasonography in diagnosing gallbladder diseases in dogs.

Gall-bladder diseases are common in dogs and two-dimensional ultrasonography is a current standard method for diagnosis and treatment planning. However, findings from this modality can be nonspecific. The aim of this retrospective, case series study was to describe conventional and contrast-enhanced ultrasound (using SonoVue® ) findings in a group of dogs with histologically confirmed gall bladder disease. A total of 65 dogs were included. Branchlike, heterogeneous, and homogeneous contrast enhancement of echogenic intraluminal mass-forming lesions was a contrast-enhanced ultrasound characteristic of polypoid lesions due to cystic mucosal hyperplasia of the gallbladder and/or tumor, which had different wash-in and washout characteristics. In dogs with mobile or immobile biliary sludge or mucocele, the echogenic intraluminal masses remained unenhanced. A double rim mark or enhancement defect in the gallbladder wall was a characteristic of edema or necrosis/rupture of the wall, respectively. Conventional ultrasonography correctly identified biliary sludge or mucocele in 36/37 dogs, cholecystitis/edema in 44/47 dogs, necrosis/rupture in 19/25 dogs, and gallbladder neoplasia in three of three dogs with these pathologies. It falsely identified biliary sludge or mucocele in eight of 28 dogs, cholecystitis/edema in three of 15 dogs, necrosis/rupture in 13/37 dogs, and gall-bladder neoplasia in 20/59 dogs that did not have these pathologies. Contrast-enhanced ultrasound correctly identified cholecystitis/edema in 42/47 dogs, but falsely identified cholecystitis/edema in three of 18 dogs. It correctly identified necrosis/rupture, benign polypoid lesions, and gallbladder neoplasia in all dogs with no false-positive results. Findings supported contrast-enhanced ultrasound as a complement to conventional ultrasonography for dogs with suspected gallbladder pathologies such as edema, necrosis, and rupture.

Xanthogranulomatous cholecystitis shows overlapping histological features with IgG4-related cholecystitis.

Xanthogranulomatous cholecystitis (XGC), an unusual histological variant of chronic cholecystitis, is characterised by mixed foamy histiocytic and lymphoplasmocytic infiltration and fibrosis. Radiologically, the poorly defined nodular growth pattern often leads to the misinterpretation of XGC as gallbladder cancer. In this study, we aimed to identify the relationship of XGC with IgG4-related cholecystitis. We re-evaluated 57 surgically resected XGCs and 104 conventional chronic cholecystitis cases, according to the histological features observed in IgG4-related disease, including lymphoplasmocytic infiltration, storiform fibrosis, obliterative phlebitis, and IgG4-positive plasma cells. XGCs contained a significantly increased mean number of IgG4-positive plasma cells [34.8/high-power field (HPF)] as compared with conventional chronic cholecystitis (4.8/HPF; P<0.001), and 16 XGCs (28%) harboured >50 IgG4-positive cells per HPF. Nine XGCs (16%), including one case with IgG4-related autoimmune pancreatitis, showed 'the histological features suggestive of IgG4-related disease', as described in the consensus statement regarding this condition. Extracholecystic inflammatory extension (seven cases, P=0.009) and mass-forming lesions (eight cases, P<0.001) were more frequently seen in XGC cases with histological features suggestive of IgG4-related disease than in cases without those microscopic changes. XGCs with IgG4-positive cell infiltration are considered to be mimickers, as xanthogranulomatous inflammation generally contradicts a diagnosis of IgG4-related disease and is weakly associated with other typical organ manifestations of IgG4-related disease. However, XGC may be a concurrent condition, particularly in patients with IgG4-related disease in other organs.

Splenic hamartoma is a rare cause of abdominal pain: Case report and literature review.

Hamartoma is a rare benign tumor of the spleen. It is often asymptomatic and diagnosed incidentally. In this study, we report the case of a 51-year-old female patient who was admitted to our department for intermittent epigastric pain since the last 6 months and left upper quadrant fullness. She was diagnosed with splenic hamartoma histopathologically after splenectomy. Although splenic hamartoma is very rare, it must be included in the differential diagnosis of splenic mass-forming lesions.

Computed Tomography and Magnetic Resonance Imaging Findings of Inflammatory Pseudotumors in the Abdomen and Pelvis: Current Concepts and Pictorial Review

The group of inflammatory pseudotumors (IPTs) encompasses a variety of rare neoplastic and nonneoplastic entities described to occur in almost every location in the body and whose clinical features and aggressive imaging findings (varying from infiltrative to mass-forming lesions), frequently mimic those of malignant tumors. The radiologic features of IPTs are variable and nonspecific, the imaging findings depending on the body location and involved organ. Abdominopelvic IPTs are rare and the purposes of this review, therefore, are to familiarize the radiologist with the wide spectrum of computed tomography and magnetic resonance imaging findings of IPTs in various locations throughout the abdomen and pelvis, discussing the imaging features that allow consideration of IPTs in the differential diagnosis of soft-tissue masses within the pertinent clinical setting. Radiologists should be aware of this group of entities, as a preoperative histopathologic diagnosis upon radiological suspicion may help to differentiate IPTs from malignancy and to allow the most appropriate clinical work-up for these patients.

Mass-forming lesions of the duodenum: A pictorial review.

Recent advances in imaging have resulted in marked changes in the investigation of the duodenum, which still remains primarily evaluated with videoendoscopy. However, improvements in computed tomography (CT) and magnetic resonance (MR) imaging have made detection and characterization of duodenal mass-forming abnormalities easier. The goal of this pictorial review was to illustrate the most common conditions of the duodenum that present as mass-forming lesions with a specific emphasis on CT and MR imaging. MR imaging used in conjunction with duodenal distension appears as a second line imaging modality for the characterization of duodenal mass-forming lesions. CT remains the first line imaging modality for the detection and characterization of a wide range of duodenal mass-forming lesions.

Current Concepts and Diagnosis of IgG4-Related Pancreatitis (Type 1 AIP).

Although now considered to be a member of the systemic entity of immunoglobulin G4- (IgG4-) related disease, IgG4-related pancreatitis is generally referred to as type 1 autoimmune pancreatitis (AIP). Type 1 AIP was established based on a pathological background of lymphoplasmacytic sclerosing pancreatitis, high serum IgG4 concentration, and abundant IgG4-bearing plasma cell infiltration. The characteristic clinical features of type 1 AIP, such as elderly male preponderance, obstructive jaundice, and mass-forming lesions in the pancreas, often mimic those of pancreatic cancer. However, because AIP responds favorably to corticosteroid treatment, careful differentiation from pancreatic cancer is required. An AIP diagnosis is currently based on the 2011 International Consensus Diagnostic Criteria for AIP, which are based on high sensitivity, selectivity, and accuracy. Over the long term, AIP can progress to a chronic condition, with pancreatic stone formation and atrophy resembling that of chronic pancreatitis. Although AIP has been linked to the complication of malignancies, it remains controversial whether an association exists between the disease and tumor formation.

Isolated Mass-Forming IgG4-Related Cholangitis as an Initial Clinical Presentation of Systemic IgG4-Related Disease.

IgG4-related disease (IgG4-RD) may involve multiple organs. Although it usually presents as diffuse organ involvement, localized mass-forming lesions have been occasionally encountered in pancreas. However, the same pattern has been seldom reported in biliary tract. A 61-year-old male showed a hilar bile duct mass with multiple enlarged lymph nodes in imaging studies and he underwent trisectionectomy under impression of cholangiocarcinoma. Gross examination revealed a mass-like lesion around hilar bile duct. Histopathologically, dense lymphoplasmacytic infiltration and storiform fibrosis were identified without evidence of malignancy. Immunohistochemical stain demonstrated rich IgG4-positive plasma cell infiltration. Follow-up imaging studies disclosed multiple enlarged lymph nodes with involvement of pancreas and perisplenic soft tissue. The lesions have been significantly reduced after steroid treatment, which suggests multi-organ involvement of systemic IgG4-RD. Here, we report an unusual localized mass-forming IgG4-related cholangitis as an initial presentation of IgG4-RD, which was biliary manifestation of systemic IgG4-related autoimmune disease.

Unilateral orbital mass as an unusual presentation of IgG4-related disease

IgG4-related diseases are a recently recognized systemic syndrome characterized by mass-forming lesions, in mainly exocrine tissue, that consist of lymphoplasmacytic infiltrates and sclerosis, which may mimic malignant neoplasm due to clinical and imaging features. We report an unusual case of a 62-year-old woman who presented with a left orbital mass, which histologically revealed to be an IgG4-sclerosing disease.

Shedding light on inflammatory pseudotumor in children: spotlight on inflammatory myofibroblastic tumor.

Inflammatory pseudotumor is a generic term used to designate a heterogeneous group of inflammatory mass-forming lesions histologically characterized by myofibroblastic proliferation with chronic inflammatory infiltrate. Inflammatory pseudotumor is multifactorial in etiology and generally benign, but it is often mistaken for malignancy given its aggressive appearance. It can occur throughout the body and is seen in all age groups. Inflammatory pseudotumor has been described in the literature by many organ-specific names, resulting in confusion. Recently within this generic category of inflammatory pseudotumor, inflammatory myofibroblastic tumor has emerged as a distinct entity and is now recognized as a fibroblastic/myofibroblastic neoplasm with intermediate biological potential and occurring mostly in children. We present interesting pediatric cases of inflammatory myofibroblastic tumors given this entity's tendency to occur in children. Familiarity and knowledge of the imaging features of inflammatory pseudotumor can help in making an accurate diagnosis, thereby avoiding unnecessary radical surgery.

A case of probable IgG4-related disease involving the unilateral trigeminal nerve of the cheek region

Immunoglobulin G4 (IgG4)-related disease comprises a recently recognized systemic syndrome char- acterized by mass-forming lesions that are found mainly in exocrine tissue and consist of lymphoplasmacytic infil- trates and sclerosis. There are numerous IgG4-positive plasma cells in the affected tissues, and the serum IgG4 level is increased in patients. The subject was a 77-year-old man with pathologically provable IgG4-related disease involving the unilateral trigeminal nerve in the left cheek region. A tumor-like lesion measuring 40 9 15 9 15 mm in the soft tissues of the left cheek was observed on com- puted tomography and magnetic resonance imaging, and extended along the infraorbital nerves to the anterior region of the maxilla. The mass was hypointense on T2-weighted images and showed mild contrast enhancement. Positron emission tomography showed accumulation in the left cheek (SUVmax: 3.9). Lymphoid follicles of various sizes surrounded by fibrosis were seen in the resected tumor. Immunostaining for IgG and IgG4 showed diffuse distribution of IgG- and IgG4-positive plasma cells in the interfollicular area, and the ratio of IgG4-positive plasma cells to IgG-positive plasma cells was 59 %. IgG4-related disease of the head and neck may be suggested by the combination of clinical signs and symptoms and radiologic findings of an infiltrative mass lesion. Although a definitive diagnosis cannot presently be obtained using IgG4-related disease comprehensive diagnostic criteria, we concluded that the present case was IgG4-related disease based on the good clinical course.

Metabolic signatures of malignant and non-malignant mass-forming lesions in the periampulla and pancreas in FDG PET/CT scan: an atlas with pathologic correlation.

Positron emission tomography (PET) has been used for the characterization of pancreatic and periampullary lesions. Pancreatitis-associated inflammation affecting only a portion of the pancreas gives the appearance of a mass lesion on imaging. Consequently, the differential diagnosis between cancer and pancreatitis becomes a commonly encountered problem. Traditionally, PET was interpreted as positive (to denote malignancy) if fluorodeoxyglucose (FDG) activity in the pancreas exceeded background activity and as negative (to denote benign) if activity was less than or equal to background activity. However, the specificity was limited with this method of interpretation. A relatively wide overlap has been reported between semiquantitative uptake values obtained in cancers and those in inflammatory lesions. Also, the qualitative (metabolic patterns) and quantitative variables (standardized uptake values) have been complementary and at sometimes controversial to each other in various clinical situations. There is paucity of data in the literature highlighting the role of FDG PET/CT in characterization of such mass lesions. The primary aim of this pictorial review is to list the various pathologic processes of pancreas and periampulla that could be studied with FDG PET/CT and recognize the different FDG uptake patterns and apply this information to characterize the different lesions affecting the pancreas and periampulla. We have also discussed the limitations of conventional imaging and advantages of FDG PET/CT for the evaluation mass-forming lesions of the pancreas and periampulla.

IgG4-associated cholangitis: a comprehensive review.

IgG4-associated cholangitis (IAC) is a major manifestation of immunoglobulin G4-related disease (IgG4-RD), an inflammatory multiorgan disorder of unknown cause. IAC and autoimmune pancreatitis (AIP) may mimic sclerosing cholangitis, cholangiocarcinoma, or pancreatic carcinoma. Typically, elderly male patients present with abdominal discomfort, weight loss, jaundice, and itch. At present, no accurate diagnostic test for IAC and IgG4-RD is at hand, often causing significant diagnostic delay. Serum IgG4 is only diagnostic when markedly raised (>4× ULN). Imaging in IAC discloses mass-forming lesions and/or strictures in the biliary tract. Histology may show tissue infiltration of IgG4-expressing plasma cells. Diagnostic criteria for histologic and imaging findings, serum tests, organ manifestation pattern, and response to immunosuppressive therapy (HISORt) criteria are used for the diagnosis of IgG4-RD. Still, considering the difficulty in diagnosing IAC and AIP, unnecessary hepatic or pancreatic resections for presumed malignancies occur. The good response to corticosteroid therapy in IAC and other manifestations of IgG4-RD suggests an immune-mediated inflammatory disease. Maintenance immunosuppression after induction of remission is needed in the majority of patients to avoid relapse. The pathogenesis of IAC and IgG4-RD remains poorly understood. Unresolved questions include: (i) Does IgG4 have a pro- or anti-inflammatory role in IAC? (ii) Is IAC a B cell- and/or T cell-mediated disease? (iii) Which are the molecular targets attacked by the immune system in IgG4-RD? Here, we review the diagnostic and therapeutic management of the disease and discuss recent pathophysiological findings, which might help to better understand the molecular mechanisms contributing to IAC and other manifestations of IgG4-RD.

Abnormal Expression of CD20 on IgG4 Plasma Cells Associated With IgG4-Related Lymphadenopathy

Immunoglobulin G4 (IgG4)-related disease is a recently described entity that presents as mass-forming lesions in soft tissue, exocrine glands, and in lymph nodes as IgG4-related lymphadenopathy. The underlying pathologic mechanism of IgG4-related disease is unclear; however, rituximab (an anti-CD20 monoclonal antibody) has been shown to have clinical efficacy. To look for the presence or absence of CD20 on the IgG4-expressing plasma cells in IgG4-related lymphadenopathy. Twelve flow cytometry cases were identified through a retrospective review from the authors' institutions files. Cases were selected by the presence of a lymph node biopsy specimen with increased IgG4 plasma cells by immunohistochemistry and a histologic diagnosis compatible with IgG4-related lymphadenopathy. We report dim CD20 expression on plasma cells in all cases for which a plasma cell population was clearly identified by flow cytometry. These cases were from patients with lymph node biopsy specimens that met published criteria for IgG4-related lymphadenopathy. This finding may be one potential explanation for the clinical efficacy of rituximab in IgG4-related disease.

OP0110 The utility of fluorodeoxyglucose-positron emission tomography for IgG4-related disease diagnosed accorgding to comprehensive diagnostic criteria

BackgroundIgG4-related disease (IgG4-RD) is a systemic disease characterized by elevated levels of serum IgG4 (sG4) and mass-forming lesions infiltrated with IgG4-positive (IgG4+) plasma cell. To date in our facilities, IgG4-RD...

IgG4-related disease of the ureter: report of two cases and review of the literature

IgG4-related disease (IgG4-RD) is a recently recognized multi-organ fibro-inflammatory lesion characterized by elevated IgG4 serum levels and mass-forming lesions. This condition shows similar histological features independently of the site of origin including storiform fibrosis, obliterative phlebitis, and dense lymphoplasmacytic infiltrate with a conspicuous IgG4-positive plasma cell component. Since this disease has only recently been categorized as a single specific nosologic entity, lesions with these typical morphological features have previously been named in different ways, creating some confusion and making it difficult to identify cases published in the literature. Lesions with features suggesting IgG4-RDs have very rarely been reported in the ureter, and they have been named using the terms "inflammatory pseudotumor" and "idiopathic segmental ureteritis." Herein, we describe the clinicopathological features of ureteral IgG4-RD found in two different patients. An 82-year-old female and a 77-year-old male underwent ureteral resection due to severe ureteral wall thickness and lumen stenosis suggestive of urothelial carcinoma. However, histological examinations showed transmural fibro-inflammatory lesions, with abundant IgG4 plasma cells intermixed with histiocytes, lymphocytes, fibroblasts, and scattered eosinophils. We have also accurately reviewed the literature in order to identify, among lesions diagnosed with different names, examples of ureteral IgG4-related lesions to give the reader a comprehensive overview of this relatively rare inflammatory disease. We suggest using the name "ureteral IgG4-RD" for those lesions showing the same morphological features as IgG4-RDs located elsewhere.

Clinicopathologic analysis of IgG4-related skin disease

IgG4-related disease is a recently recognized systemic syndrome characterized by mass-forming lesions with lymphoplasmacytic infiltration, increase in the number of IgG4+ cells in affected tissues and elevation of serum IgG4 levels. In 2009, we were the first to report skin lesions in patients with IgG4-related disease, but no large case series has been reported and clinicopathological findings remain unclear. To clarify these features, we herein report 10 patients (9 men and 1 woman; median age, 64 years; age range, 46–81 years) with IgG4-related skin disease. All patients had erythematous and itchy plaques or subcutaneous nodules on the skin of the head and neck, particularly in the periauricular, cheek, and mandible regions, except for one patient, whose forearm and waist skin were affected. In addition, eight patients had extracutaneous lesions: these were found on the lymph nodes in six patients, the lacrimal glands in three patients, the parotid glands in three patients, and the kidney in one patient. Histologically examined extracutaneous lesions were consistent with IgG4-related disease; five of six lymph node lesions showed progressively transformed germinal centers-type IgG4-related lymphadenopathy. Cases of IgG4-related skin disease were classified into two histological patterns: those exhibiting a nodular dermatitis pattern and those with a subcutaneous nodule pattern. The infiltrate was rich in plasma cells, small lymphocytes, and eosinophils; the majority of the plasma cells were IgG4+. The IgG4+ cell count was 49–396 per high-power field (mean±s.d., 172±129), with an IgG4+/IgG+ cell ratio ranging from 62 to 92%. Serum IgG4 levels were elevated in all examined patients. In conclusion, patients with IgG4-related skin disease had uniform clinicopathology. Lesions were frequently present on the skin of the periauricular, cheek, and mandible regions, and were frequently accompanied by IgG4-related lymphadenopathy.

Isolated IgG4-related interstitial lung disease: unusual histological and radiological features of a pathologically proven case

IgG4-related lung disease is commonly associated with autoimmune pancreatitis. Recently, isolated IgG4-related interstitial lung disease (ILD) without other organ involvement has newly been reported in two cases with clinical features of nonspecific interstitial pneumonitis (NSIP).We report the first case of an isolated IgG4-related ILD in a 78-year-old man with dry cough and dyspnea, whose clinical findings proved to be different from NSIP. Serum IgG4 levels were increased. Chest CT scan revealed bilateral consolidations especially in the lower lobes, enlarged mediastinal and hilar lymph nodes and pleural effusions. Video-assisted thoracoscopic (VATS) lung biopsy revealed a pattern similar to usual interstitial pneumonia (UIP) and an abundant IgG4-positive plasma cell infiltration. He was effectively treated by steroid therapy.Increasing recognition of IgG4 related diseases has led to a growing number of new entities. The novel concept of isolated IgG4-related ILD as a pulmonary manifestation of a systemic IgG4-related disorder should be taken into account as a possible differential diagnosis of ILD and mass-forming lesions, even when no other organ manifestation is clinically apparent at the time of diagnosis. Lung specific diagnostic criteria and algorithms are required to enhance diagnostic accuracy in cases of possible IgG4-related ILD.

Isolated IgG4-related interstitial lung disease: unusual histological and radiological features of a pathologically proven case

IgG4-related lung disease is commonly associated with autoimmune pancreatitis. Recently, isolated IgG4-related interstitial lung disease (ILD) without other organ involvement has newly been reported in two cases with clinical features of nonspecific interstitial pneumonitis (NSIP). We report the first case of an isolated IgG4-related ILD in a 78-year-old man with dry cough and dyspnea, whose clinical findings proved to be different from NSIP. Serum IgG4 levels were increased. Chest CT scan revealed bilateral consolidations especially in the lower lobes, enlarged mediastinal and hilar lymph nodes and pleural effusions. Video-assisted thoracoscopic (VATS) lung biopsy revealed a pattern similar to usual interstitial pneumonia (UIP) and an abundant IgG4-positive plasma cell infiltration. He was effectively treated by steroid therapy. Increasing recognition of IgG4 related diseases has led to a growing number of new entities. The novel concept of isolated IgG4-related ILD as a pulmonary manifestation of a systemic IgG4-related disorder should be taken into account as a possible differential diagnosis of ILD and mass-forming lesions, even when no other organ manifestation is clinically apparent at the time of diagnosis. Lung specific diagnostic criteria and algorithms are required to enhance diagnostic accuracy in cases of possible IgG4-related ILD.

Role of 18F‐fluorodeoxyglucose positron emission tomography/computed tomography in the characterization of pancreatic masses: Experience from tropics

Early detection and differentiation of malignant from benign pancreatic tumors is very essential as mass-forming pancreatitis is a frequently encountered problem. Positron emission tomography (PET) has a role in establishing the diagnosis of pancreatic carcinoma when the conventional imaging modalities or biopsies are nondiagnostic. In this prospective study, the utility of fluorodeoxyglucose (FDG)-PET/computed tomography (CT) in the characterization of mass-forming lesions of the pancreas was reported. (18)F-FDG-PET/CT was prospectively performed in 87 patients diagnosed to have periampullary or pancreatic mass. Lesions with focally increased FDG uptake in PET/CT were considered malignant, whereas those with diffuse or no FDG uptake were considered benign. Semiquantitative analysis with maximum standardized uptake value (SUVmax) was also calculated. The PET/CT results were compared with histopathological results in all patients. Based on the FDG uptake pattern, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for FDG-PET/CT in characterizing the periampullary and pancreatic masses into benign and malignant lesions were 93%, 90%, 95%, 87%, and 92% respectively. Receiver operating characteristics curve analysis of the SUVmax of the lesions yielded a cut-off value of 2.8, with a sensitivity and specificity of 87.5% and 45% respectively. The FDG uptake pattern in PET/CT can differentiate malignant from benign mass-forming lesions of the pancreas with high accuracy and a discrete cut-off value of SUVmax could not be defined for the same as even lesions with pancreatic tuberculosis showed very high FDG uptake. Hence, in patients with a suspicion of malignancy in the pancreas, a focally increase FDG uptake in PET/CT suggests the diagnosis of malignancy.

Testicular adrenal rest "tumor" or Leydig cell tumor? A report of a challenging case with literature review

Congenital adrenal hyperplasia (CAH) refers to group of inherited diseases resulting from impaired adrenal steroidogenesis, and its most common cause is 21-hydroxylase deficiency. Testicular adrenal rest tumors (TARTs) are an important complication of CAH, which probably develop from ectopic remnants of intra-testicular adrenal tissue stimulated by Adrenocorticotropic hormone (ACTH) hypersecretion. These lesions are typically located within the rete testis and are bilateral, synchronous, nodular and multiple. TART usually, but not always, responses to suppressive medical therapy. TART leads to testicular structural damage, spermatogenesis disorders, infertility and most importantly, mass-forming lesions that could be mistaken for Leydig cell tumor (LCT). The later has a significantly different behavior with up to 10% of being malignant. Nowadays, due to advances in diagnosing and treating CAH, mass-forming TART is rarely encountered. As a result, there is the paucity in the medical literature regarding its features from pathological perspective. We herein present a case of mass-forming TART and we discuss the clinical, radiological, and morphological features as well as the major differential diagnosis of this rare lesion.