Immunoglobulin G4-related disease with Marked Eosinophilia: A Case Report and Literature Review

We encountered a 78-year-old Japanese man with IgG4-related sialoadenitis complicated with marked eosinophilia. We diagnosed him with IgG4-RD (related disease) with a submandibular gland tumor, serum IgG4 elevation, IgG4-positive plasma cell infiltration, and storiform fibrosis. During follow-up after total incision of the submandibular gland, the peripheral eosinophil count was markedly elevated to 29,480/μL. The differential diagnosis of severe eosinophilia without IgG4-RD was excluded. The patient exhibited a prompt response to corticosteroid therapy. His peripheral blood eosinophil count was the highest ever reported among similar cases. We also review previous cases of IgG4-RD with severe eosinophilia.

The unique diagnostic and management challenge of a patient with concomitant anti-interferon-gamma autoantibody associated immunodeficiency syndrome, IgG4-related disease, and treatment refractory, disseminated mycobacterium avium complex infection

BACKGROUND

Anti-interferon-gamma autoantibody-associated immunodeficiency syndrome is a rare and underrecognized adult onset immunodeficiency syndrome associated with severe opportunistic infections such as disseminated nontuberculous mycobacterium. Few cases have documented a relationship with IgG4-related disease. Concomitant diagnoses of these diseases present a diagnostic and management challenge.

CASE PRESENTATION

A 61 year old man of Southeast Asian descent with pulmonary mycobacterium avium complex infection presented to our hospital system with a new skin rash and worsening lymphadenopathy. He was eventually diagnosed with IgG4-related disease through excisional nodal biopsy. He was managed with immunosuppressive treatment with prednisone, rituximab and cyclophosphamide. He later re-presented with disseminated mycobacterium avium complex infiltration of his joints, bones and prostate. Original titers of anti-interferon-gamma autoantibodies were falsely negative due to being on immunosuppressive therapy for his IgG4-related disease. However, anti-interferon-gamma autoantibody titers were re-sent after immunosuppression was held and returned strongly positive.

CONCLUSIONS

This case reviews diagnostic criteria and discusses management strategies with existing challenges in treating a patient with concomitant adult onset immunodeficiency syndrome, IgG4-related disease and a disseminated mycobacterial avium complex infection.

The Role of IgG4 in Autoimmunity and Rheumatic Diseases

The distinguishing of the IgG4-related disease (IgG4-RD) from among other rheumatic diseases has brought attention to the IgG4 subclass of immunoglobulins. It is the least numerous subclass among immunoglobulins G. In general, IgG4 is considered to be non-inflammatory and tolerance inducing, due to its unique structure. However, in IgG4-RD this antibody plays a pathogenic role in activation of the fibrinogenesis and of the inflammatory process; there are also suggestions that it may be a marker of an abnormal inflammatory response. The importance of IgG4 for the pathogenesis of allergic diseases, with a vital role of its ratio to immunoglobulin E (IgE/IgG4 ratio), has been known for years. The role of IgG4 in the course and pathogenesis of rheumatic diseases is still being researched and is not yet fully understood. Increased IgG4 levels have been revealed in rheumatoid arthritis, although no clear link between this phenomenon and disease activity has been demonstrated. There are articles on the potential importance of IgG4 concentration (of both elevated and decreased serum levels) in Sjogren’s syndrome. Additionally, anti-nuclear IgG4 antibody significant titers have been detected in SLE patients, and it has been suggested that the effect of these antibodies on complement consumption and the production of proinflammatory cytokines may play a role in inhibiting the progression of SLE. IgG4 plays a role in autoimmune diseases other than rheumatic diseases, such as pemphigus, bullous pemphigoid, idiopathic membranous glomerulonephritis, or myasthenia gravis, but also in helmints infections. Research shows the importance of IgG4 in malignancy of neoplasms. Melanoma cells are known to stimulate IgG4 production through a modified Th2-based inflammatory response. The role of this immunoglobulin in cholangiocarcinoma is also considered as possible. The aim of this review article is to discuss the current knowledge of IgG4 not only from the perspective of the IgG4-RD but also from a point of view of other autoimmune diseases with particular emphasis on rheumatic diseases.

T-Cell-Driven Fibroinflammation Inducing Follicular Dedifferentiation in Alopecia Areata and IgG4-Modified Disease

ABSTRACT

The definition of IgG4-related diseases incorporates a broad range of systemic diseases particularly a subset dominated by fibroinflammation. CD4+cytotoxic T cells have emerged as the major driving force for the fibroinflammation, and the pathogenetic role of IgG4 still remains to be determined. Cutaneous involvement is uncommon and is not well defined as elevated tissue IgG4 plasma cells are not a specific marker and prominent cutaneous fibroinflammation is often absent in cutaneous disease. We report the case of a patient with longstanding alopecia universalis and severe atopic dermatitis who presented with diffuse induration and mottled dyspigmentation of his scalp. Multiple scalp biopsies revealed diffuse interfollicular fibroinflammation and IgG4 plasma cells with induction of distinctive dedifferentiated follicles not seen in alopecia areata. This complex case may provide insight into the role of specific subsets of T cells not only in respect to the fibroinflammation linked to IgG4-related diseases but also the capacity to modify disease, follicular stem cell activation, immune privilege, cytotoxicity in alopecia areata, and the presence of atopy that may have contributed to the pathogenesis of this case.

IgG4-related tubulointerstitial nephritis

A 67-year-old man was referred to the renal team following an episode of acute kidney injury on a background of chronic kidney disease. He had a 9-year history of steroid-sensitive arthritis, epigastric pain and isolated submandibular gland enlargement. He was noted to have a raised eosinophil count, total serum protein and total immunoglobulin G4 (IgG4) level as well as a serum hypocomplementaemia. A renal biopsy showed a tubulointerstitial nephritis with lymphoplasmacytic infiltrates, fibrosis and IgG4-positive plasma cells on immunohistochemistry. A diagnosis of IgG4-related disease was made based on clinical presentation and pathology. Renal function improved with glucocorticoids and the patient was successfully transitioned to azathioprine as a steroid-sparing agent.

IgG4-Related Disease With Renal and Pulmonary Involvement

Immunoglobulin G4-related disease (IgG4-RD) is a rare immune-mediated disease affecting multiple organs and tissues. There is often the presence of elevated serum Ig4 subtype with histological evidence of lymphoplasmacytic infiltration, fibrosis, and phlebitis. The mainstay of treatment is steroids therapy. We report the case of a 66-year-old man presenting with acute on chronic renal failure and pulmonary nodules seen on PET-CT scan. He also had elevated serum IgG4 subclass and histological features in keeping with IgG4-RD. He failed steroid therapy but responded subsequently to rituximab with complete resolution of his symptoms.

IgG4-related hypophysitis

Hypophysitis is a rare pituitary inflammatory disorder classified in different ways. Immunoglobulin G4-related disease (IgG4-RD), also a rare disease is a systemic fibro-inflammatory condition characterized by infiltration of tissue with IgG4-positive plasma cells; however prevalence of both of them probably is underestimated. In this paper, we present an Iranian patient with biopsy-proven IgG4-related hypophysitis and then review the clinical characteristics, laboratory, imaging, pathologic findings and therapeutic management as well as prognosis of 115 published cases of hypophysitis secondary to IgG4-related disease.

A comparative study of Kimura's disease and IgG4-related disease: similarities, differences and overlapping features

AIMS

To compare the fibroinflammatory diseases Kimura's disease (KD) and immunoglobulin (Ig)G4-related disease (IgG4RD) and to explore their possible relationship.

METHODS AND RESULTS

Forty-six cases of KD and 29 IgG4RD from our institution diagnosed from 2011 to 2020 were studied. They were compared with each other on clinical, pathological and immunohistological features. There were similar clinical features, except that IgG4RD affected an older patient population, with more frequent salivary gland involvement and KD affected head and neck lymph nodes, and showed blood eosinophilia more frequently than IgG4RD. IgG4RD exhibited frequent storiform fibrosis and obliterative phlebitis, while KD showed more frequent tissue eosinophilia, eosinophilic abscess, germinal centre eosinophilic deposit and vascularisation. Twenty to 30% of KD had more than 50 IgG4⁺ plasma cells (PC) per high-power field (HPF) and IgG4/IgG⁺ PC ratio exceeding 40%. These parameters, however, occurred in 100% of IgG4RD. Significantly more KD had >10 IgE⁺ PC/HPF and lymphoid germinal centre IgE reticular staining compared to IgG4RD. All these histological and immunohistological features are overlapping in the two diseases, although they differed with statistical significance.

CONCLUSION

Our study confirmed that there is significant overlap in clinical, pathological and immunohistological features between KD and IgG4RD. It is important to recognise these overlapping features, and correlation with a clinicopathological picture is required in differential diagnoses. The overlapping features also suggest a possible close relationship between KD and IgG4RD, which could represent different facets of a continuous fibroinflammatory disease spectrum.

"Migratory Kerato osteomyelitis" - A refractory lesion of the mandible: A pathologist's and surgeon's dilemma!!

A 62 year old female patient presented with a chief complaint of non healing extraction socket in the lower left back teeth region. She underwent extraction of 37 at a private clinic following which an ulceroinfiltrative lesion developed at operated side. Multiple biopsies from the lesion were inconclusive. Computed tomography revealed an osteolytic lesion radiologically simulating carcinoma or a chondrosarcoma. Because of persistent debilitating symptoms the patient underwent Wide local excision (WLE) with left segmental mandibulectomy. Frozen sections were negative for malignancy. All margins were free from malignancy. Lymph nodes dissected showed reactive morphology. Ziehl-Neelsen, Periodic acid-Schiff and Gram stain were all negative. The lesion continued to spread even after successful surgical intervention with adequate surgical margin. The patient was eventually lost because of severe cardiac arrest during her last surgical intervention for mandibular arch reconstruction. As the lesion migrated from one side of the mandible to the other, kept showing clinical features of inflammation of the bone and bone marrow simulating features of osteomyelitis and the continued presence of keratin histologically, we contemplated whether we could give a nomenclature to the lesion as that of "Migratory Kerato osteomyelitis of the oral cavity." This could be one of case of a lifetime where multiple consultations with oral and general pathologists failed to reach a conclusive diagnosis!

IgG4-related disease: a great mimicker of lung cancer

IgG4-related disease is a rheumatological disorder, affecting multiple organ systems, and displaying dense lymphoplasmacytic inflammatory infiltrate and storiform fibrosis on histology. The pulmonary manifestations of IgG4-related disease are varied. Most commonly, bronchovascular consolidation and perilymphatic parenchymal thickening occur. IgG4-related disease can present as a solitary parenchymal mass and is often mistaken for a primary pulmonary or haematological malignancy. This report presents a case of IgG4-related disease in a patient with 6 months reported haemoptysis symptomatology and CT findings of perihilar lymphadenopathy, multiple pulmonary parenchymal nodules and a single parenchymal mass. Clinician cognisance of the histopathological presentation of IgG4-disease is important. It should be considered as a differential in patients for which investigations have ruled out malignancy, as it is responsive to glucocorticoids in the majority of cases.

The enigmatic immunoglobulin G4-related disease and its varied cardiovascular manifestations

Immunoglobulin G4-related disease (IgG4-RD) is a systemic fibroinflammatory disease characterised by multiorgan lymphoplasmacytic infiltration, obliterative phlebitis and storiform fibrosis. It can be associated with cardiovascular pathology. The objective of this narrative review is to summarise the published literature on cardiovascular manifestations of IgG4-RD and to provide a basis for diagnosis and management of the condition by the practising cardiologist.We propose the following categorisations of cardiovascular IgG4-RD: aortitis, medium-vessel arteritis, pulmonary vascular disease, phlebitis, valvulopathy, pericarditis, myocardial disease and antineutrophilic cytoplasmic antibody-associated vasculitis. We also review herein developments in radiological diagnosis and reported medical and surgical therapies. Cardiovascular lesions frequently require procedural and/or surgical interventions, such as aortic aneurysm repair and valve replacement. IgG4-RD of the cardiovascular system results in serious complications that can be missed if not evaluated aggressively. These are likely underdiagnosed, as clinical presentations frequently mimic cardiovascular disease due to more common aetiologies (myocardial infarction, abdominal aortic aneurysm and so on). While systemic corticosteroids are the mainstay of IgG4-RD treatment, biological and disease-modifying agents are becoming more widely used. Cardiologists should be aware of cardiovascular IgG4-RD as a differential diagnosis, and understand the roles of corticosteroids, disease-modifying agents and biologicals, as well as their integration with surgical approaches. There are several knowledge gaps, including diagnosis, risk factors, pathogenesis and appropriate management in Ig4-RD of the cardiovascular system. Areas lacking well-conducted randomized trials include safety of steroids in the setting of vascular aneurysms and the role of disease-modifying drugs and biological agents in patients with established cardiovascular complications of this multifaceted enigmatic disease.

IgG4-related disease: Changing epidemiology and new thoughts on a multisystem disease

IgG4-related disease (IgG4-RD) represents an immune-mediated fibroinflammatory condition with peculiar histopathologic changes that can affect various organs. In 2012 its unified nomenclature was published, which allows to abandon other synonymous names. Up to now, only little is known about its epidemiology around the world. However, although it is generally considered a rare condition, the number of patients with IgG4-RD is increasing enormously. Likewise, the annual number of publications on this subject has increased progressively. The spectrum of clinical manifestations in IgG4-RD is highly variable, depending on the severity of the disease as well as the presence of organ(s) involvement. This review gives an overview on changing epidemiology of IgG4-RD focusing the attention on the large cohorts of patients published in the literature.

Immunoglobulin G4-associated autoimmune hepatitis with peripheral blood eosinophilia: a case report

Background

Immunoglobulin G4 (IgG4) associated autoimmune hepatitis (AIH) has been recognized as a type of autoimmune disease that responds to corticosteroid. The diagnosis is based on elevation of the serum IgG4 level, abundance of IgG4 enhanced plasma cell infiltration in the portal region of the liver, and satisfaction of the criteria for “definite AIH” under the revised International Autoimmune Hepatitis Group (IAIHG) scoring system. However, the clinical course of the disease is unclear.

Case presentation

A 65-year-old man with jaundice and peripheral blood eosinophilia. His IAIHG and simplified score was compatible with definite AIH and his IgG4 level was elevated. Magnetic resonance imaging did not reveal abnormalities in the hepatobiliary system or pancreas. A liver biopsy revealed interface hepatitis with IgG4 positive plasma cell infiltration in the portal region, without evidence of bile duct injury. He responded to 4-week period of induction prednisolone therapy and had no recurring symptoms under maintenance therapy of 5 mg prednisolone during the 3-year follow up.

Conclusions

This was a rare case that demonstrated an association between IgG4 associated AIH and the presence of peripheral blood eosinophilia.

Treatment-resistant cough: a rare manifestation of IgG4-related disease involving the larynx

IgG4-related autoimmune diseases (IgG4 RD) are a relatively recently recognised group of disease processes that can affect multiple organ systems and result in protean symptoms. Here, we present a rare case of a 69-year-old man with a history of IgG4 RD affecting his lacrimal gland and pancreas who developed symptoms of severe laryngitis not responsive to usual therapy. He presented with non-productive cough, hoarseness and dyspnoea. Imaging findings suggestive of aortitis and laryngeal inflammation in the setting of his IgG4 RD history prompted treatment with rituximab, which resulted in resolution of his laryngeal symptoms. Subsequently, his cough returned and he required periodic rituximab infusions to stay symptom-free. IgG4 RD of the larynx is an uncommonly reported manifestation in literature. This disease is very responsive to anti-CD20 monoclonal antibody treatment. IgG4 RD should be considered in patients with airway symptoms that are especially refractory to usual therapy.

Immunoglobulin G4-related Disease of the Genitourinary System: Spectrum of Imaging Findings and Clinical-Pathologic Features

Immunoglobulin G4-related disease (IgG4-RD) is a systemic fibroinflammatory disease characterized by focal or diffuse organ infiltration of IgG4-bearing plasma cells. The diagnosis of IgG4-RD is based on a combination of clinical, serologic, radiologic, and histopathologic findings. IgG4-RD has been reported to affect almost all organ systems. The kidney is the most frequently involved of the genitourinary organs. The most common renal manifestation of IgG4-RD is IgG4-RD tubulointerstitial nephritis, followed by membranous glomerulonephropathy and, less frequently, obstructive nephropathy involving the renal pelvis, ureter, or retroperitoneum. Renal parenchymal lesions may appear as multiple nodular lesions, diffuse patchy infiltrative lesions, or a single nodular lesion. Multiple small nodular cortical lesions are the most common imaging findings of IgG4-RD involving the kidney. Renal pelvic, sinus, or perinephric lesions can also occur. IgG4-RD involvement of other genitourinary organs including the ureter, bladder, urethra, and male and female reproductive organs is rare compared with kidney involvement but may show variable imaging findings such as a localized mass within or surrounding the involved organ or diffuse enlargement of the involved organ. Imaging findings of IgG4-RD involving the genitourinary system are nonspecific but should be differentiated from inflammatory and neoplastic lesions that mimic IgG4-RD. The online slide presentation from the RSNA Annual Meeting is available for this article. ^©RSNA, 2020.

CT and MR imaging findings of ocular adnexal mucosa-associated lymphoid tissue lymphoma associated with IgG4-related disease: multi-institutional case series

AIM

To report CT and MR imaging findings of ocular adnexal mucosa-associated lymphoid tissue lymphoma associated with IgG4-related disease (IgG4-MALT lymphoma), a rare but clinically important complication of ocular adnexal IgG4-related disease.

METHODS

We retrospectively reviewed all cases of histologically confirmed ocular adnexal IgG4-related disease at three tertiary and one secondary referral centers, between February 2003 and December 2016. Seven cases of histopathologically diagnosed IgG4-MALT lymphoma were identified. CT and MR images were analyzed by consensus of two experienced head and neck radiologists.

RESULTS

Lacrimal glands were the main site of involvement in all seven patients. The lesions typically showed well-demarcated margins, iso- to hyperattenuation on precontrast CT, T2 hypo- to isointensity, T1 isointensity, and homogenous internal architecture with homogenous enhancement pattern. Lesions were mostly hyperdense and isointense to normal extraocular muscles on postcontrast CT and MR images, respectively.

CONCLUSION

Unlike in typical ocular adnexal IgG4-related disease, T2 isointensity and hyperattenuation on precontrast CT images were noted in some IgG4-MALT lymphoma cases. Although the findings may be nonspecific, the possibility of accompanying MALT lymphoma may need to be considered, when ocular adnexal lesions in patients clinically suspected of having IgG4-related disease are refractory to glucocorticoids and show T2 isointensity and hyperattenuation on precontrast CT for the optimal management of the patients. However, this is a case series of a very rare complication of ocular adnexal IgG4-related disease, and thus caution is warranted to generalize the conclusion.

A Case of an IgG4-Related Disease Mimicking Malignancy and Resolving With Steroids

A 77-year-old African American female was referred to oncology for evaluation of an adrenal fossa mass detected on computed tomography scan of the abdomen and pelvis (CT-scan A/P) that was ordered as a work-up for painless hematuria. Further evaluation by positron emission tomography (PET) scan showed hypermetabolic masses in the left suprarenal and right iliac region. The biopsy of the right iliac mass was consistent with IgG4-related disease (IgG4RD). It was supported by an elevated serum IgG4 level. She was treated with prednisone with a good response.

Primary hepatic extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), is one of the specific type of low-grade B-cell lymphoma not infrequently found worldwide. It typically involves mucosal sites such as stomach and conjunctiva; however, primary hepatic MALT lymphoma has been extremely rarely reported. We describe a case of hepatic MALT lymphoma in a 70-year-old male patient who underwent left hepatectomy due to the incidentally detected liver masses at a medical checkup. The resected specimen revealed multinodular masses consisting of small-to-intermediate-sized lymphoid cells with serpentine pattern and focal lymphoepithelial lesions. The tumor cells were diffusely positive for CD20 and Bcl-2 but negative for CD3, CD10, CD5, CD23, CD43, and cyclinD1. The Ki-67 labeling index was 10% and immunoglobulin heavy chain gene rearrangement study confirmed monoclonal proliferation. In this paper, we discuss several unique clinicopathologic characteristics which will be helpful to the differential diagnosis of hepatic MALT lymphoma.

Immunoglobulin G4-related lacrimal sac dacryocystocele: A novel case report

Purpose

Immunoglobulin G4-related disease is a systemic fibroinflammatory disease of unknown etiology. Immunoglobulin G4-related ophthalmic disease (IgG4-ROD) can manifest in multiple ways, but lacrimal sac involvement is rare. We present the first case in Chinese population of lacrimal sac IgG4-ROD.

Observations

Lacrimal sac IgG4-ROD is rare, and only 9 cases were reported in literature. Despite reported cases in Asian population, mainly in Japan, there was none from the Chinese population or South Asia. Our index case is a 67-year-old Chinese male, who presented with a left insidious nasolacrimal duct swelling mimicking dacryocystocele. Lacrimal sac IgG4-ROD was diagnosed with radiological, serological, pathological and immunohistochemical evidence. The under-reporting of this disease entity may suggest a benign course of such.

Conclusions and importance

This is the first reported case of biopsy proven lacrimal sac definite IgG4-ROD in Chinese patient on English literature. With the limited cases reported in literature, the pathology of Immunoglobulin G4 immune process in lacrimal sac demands further investigation.

Recurrent metastatic primary inflammatory myofibroblast tumour of the gallbladder following pancreaticoduodenectomy

Inflammatory myofibroblast tumour (IMT) is an uncommon soft tissue tumour with an unpredictable clinical course: mostly benign, occasionally locally aggressive and rarely capable of metastasis. Diagnosed mainly in the mesentery, omentum, retroperitoneum, pelvis and lungs, IMT is extremely rare as a primary gallbladder tumour. Despite improved radiographical capabilities, differentiating the tumour from other more common causes of gallbladder neoplasms necessitates histopathological and immunohistochemistry tests. Once diagnosed, malignant potential should be taken into consideration, striving for an en bloc R0 resection and postoperative long-term follow-up with routine ancillary imaging. The authors present the case of a recurrent primary IMT of the gallbladder, after two surgical treatments, including a pancreaticoduodenectomy. Now 3 years after initial diagnoses the patient is asymptomatic, but has developed local and distant metastases and is being treated with systemic corticosteroid.

Orbital inflammation and colitis in pediatric IgG4-related disease: A case report and review of the literature

IgG4-related disease (IgG4-RD) is an inflammatory disorder characterized by tumor-like swelling in one or more organs, elevated serum IgG4 levels, and histological alterations with infiltration of IgG4-positive plasma cells. IgG4-RD is rare and likely underdiagnosed in children. We report a case of a 16-year-old girl with IgG4-positive colitis that developed weeks after IgG4-related ophthalmic disease and discuss diagnosis and treatment in the context of the literature available. Since the pathophysiology of IgG4-RD is unknown, treatment options are empiric and, for the most part, untargeted. Systemic corticosteroid treatment is the basis of anti-inflammatory treatment in IgG4-RD and induced early remission in our patient. During corticosteroid taper, the patient developed weight loss and intestinal inflammation. Histopathological assessment of the intestinal walls confirmed IgG4-positive colitis. Immune-modulating treatment with non-biologic (e.g., methotrexate (MTX) and mycophenolate mofetil) or biologic (rituximab) disease-modifying antirheumatic drugs has been reported in treatment refractory or corticosteroid-dependent patients. The patient responded to treatment with anti-inflammatory therapy with food rich in TGF-β2 (modulen) and MTX. This is one of the first pediatric patients reported with IgG4-related colitis extending the phenotype of pediatric IgG4-RD. International collaboration to prospectively document clinical presentation and treatment responses may help to further establish the phenotype and treatment options and to raise awareness for IgG4-RD.

Co-Occurrence of Craniopharyngioma and IgG4-Related Hypophysitis: An Epiphenomenon or a Mere Coincidence?

BACKGROUND

Craniopharyngiomas are sellar-suprasellar tumors that commonly present in children, with nonspecific symptoms of increased intracranial pressure, visual disturbances, and pituitary insufficiencies. Rarely has secondary hypophysitis (lymphocytic and xanthogranulomatous) been reported in association with craniopharyngioma.

CASE DESCRIPTION

We have reported the case of a 16-year-old boy who had presented with gradually progressive diminution of vision in the right eye, intermittent headache, deceleration in growth velocity, and the lack of development of secondary sexual characteristics. Imaging revealed a sellar-suprasellar cystic lesion (3.8 × 3.1 × 3.5 cm) with calcifications. Laboratory tests revealed hypothyroidism, hypocortisolism, hypogonadism, and growth hormone deficiency. Craniopharyngioma was provisionally diagnosed. He underwent pterional craniotomy and gross total excision of the lesion. The excised tissue showed features of adamantinomatous craniopharyngioma, with a dense lymphoplasmacytic infiltrate and fibrosis involving the pituitary and dura mater. The lymphocytes were CD20-positive, and the plasma cells stained positive for IgG4 (50-60 IgG4-positive plasma cells/high power field). Consequently, the possibility of IgG4-related hypophysitis was considered in our patient. His serum IgG4 level was not elevated. Systemic involvement by IgG4-related disease was thoroughly ruled out. Fluorodeoxyglucose positron emission tomography/computed tomography did not show any clinically significant hypermetabolism anywhere in the body. At the 3-month follow-up examination, his headache had resolved. However, he had not regained vision in his right eye. Repeat imaging studies showed no residual tumor tissue.

CONCLUSIONS

The present case might represent the first ever report, to the best of our knowledge, of secondary IgG4-related hypophysitis due to craniopharyngioma, or it might, perhaps, be a chance association of these 2 entirely different disease entities.

IgG4-Related Disease with Esophageal Involvement

We report the case of a 56-year-old man who presented with dysphagia and weight loss. An esophagoduodenoscopy revealed a severe esophageal stricture in the distal esophagus. After surgical resection, the final pathologic analysis revealed that the tumor was comprised of benign-appearing fibroinflammatory cells with an increase and predominance of IgG4-positive plasma cells. He did not, however, have any other symptoms indicative of systemic autoimmune disease or connective tissue disorders. Histologically, abundant infiltration of IgG4-positive plasma cells and lymphocytes was observed. The patient was diagnosed with IgG4-related disease, definitive, with esophageal involvement.

IgG4-related lymphadenopathy masquerading as Hodgkin lymphoma: lessons from a pathologist's desk

IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory disorder affecting multiple organ systems. The awareness of this disease has tremendously increased over the last decade leading to effective treatment and decreased morbidity to the patients. Histopathology plays an important role in the diagnosis of IgG4-RD, and definite histologic criteria are proposed in clinically suspected patients. We report a patient with multiple organ system involvements of the salivary gland, lymph node and kidney. IgG4-related lymphadenopathy (IgG4-RL) in this patient was misdiagnosed as nodular lymphocyte predominant Hodgkin's lymphoma (NLPHL). Refractoriness to treatment for NLPHL and subsequent manifestations of renal involvement lead us to the correct diagnosis of this potentially treatable condition. IgG4-RL can mimic reactive proliferation as well as lymphomas. We report the clinical presentation and discuss the problems faced by pathologists in diagnosing IgG4-RL. We believe that awareness of this rare presentation will enhance the knowledge in diagnosing IgG4-RD.

The Changing Clinical Spectrum of Hypophysitis

Hypophysitis is a rare and potentially life-threatening disease, characterized by an elevated risk of complications, such as occurrence of acute central hypoadrenalism, persistent hypopituitarism, or extension of the inflammatory process to the neighboring neurological structures. In recent years, a large number of patients have been described as being affected by hypophysitis, due to the increased administration of immuno-chemotherapies. At the present time, the heterogeneous nature of hypophysitis diagnostic criteria and of the treatment protocols makes the management of affected patients difficult. We review the current data and evidence on primary and secondary hypophysitis, in order to suggest a diagnostic and therapeutic protocol that should be focused on a multidisciplinary approach, for reaching a prompt diagnosis and an appropriate and safe treatment.

First Report of IgG4 Related Disease Primary Presenting as Vertebral Bone Marrow Lesions

IgG4-related disease is a fibro-inflammatory disorder characterized by swelling of tissues and affected organs accompanied by the development of scar tissue (fibrosis) and infiltration by IgG4 positive plasma cells. Almost any organ can be affected, including, but rarely, bone marrowinvolvement. Here we present a case of a 76-year-old male with IgG4-related disease presenting primarily with vertebral bone marrow lesions. Histopathology showed the typical features of storiform fibrosis, and increased IgG4 positive plasma cells. Treatment with corticosteroids significantly improved wellbeing and resolved lesion size on MRI.

Retrospective single-centre analysis of IgG4-related disease patient population and treatment outcomes between 2007 and 2017

Objective

The aim was to gain a better understanding of the prevalence, organ involvement, clinical characteristics and long-term outcomes of medical and surgical treatments of IgG4-related disease (IgG4-RD).

Methods

Query of the Cleveland Clinic pathology database for IgG4 plasma cell staining between 2007 and 2017 yielded 1481 results, of which 57 cases were identified as highly likely (n = 28; 49%) or probable (n = 29; 51%) IgG4-RD by histopathological criteria and IgG4 serum concentrations. Patient demographics, type of treatment and outcomes were retrieved from medical records. Patients were designated as being in remission if indicated in the chart and/or symptom- and objective finding-free for >6 months, relapsed if symptoms/findings recurred after remission, active if no remission was achieved during follow-up, and as unable to determine if the duration of follow-up was <60 days or they were lost to follow-up.

Results

Of all patients who met the IgG4 staining criteria (n = 119), half (n = 57) satisfied the IgG4-RD histopathological criteria; 63% were males, age 57.9 ± 14.8 years. The average follow-up was 2.7 ± 2.2 years. The pancreas was the most affected organ in our cohort (26.4%). Almost half of the patients (45.6%; n = 26) were managed surgically, 21.1% (n = 12) medically, and 24.6% (n = 14) received both types of treatment. Medical treatment included prednisone (45.6%), MTX (5.3%), AZA (7%) and rituximab (8.8%). Remission was achieved by 77% of patients receiving surgical, 67% receiving medical and 72% receiving both treatments.

Conclusion

A histological diagnosis of IgG4-RD could be made in half of the patients who had IgG4⁺ plasma cells ≥10/high-power field or IgG4⁺/IgG⁺ ratio >40%. In our cohort, surgical treatment compared with medical treatment had a higher proportion of remission according to our outcome classification.

Parathyroid adenoma with prominent lymphocytic infiltrate having histological features highly suggestive of IgG4-related disease: a case report and literature review

Parathyroid adenoma with prominent lymphocytic infiltrate is a rare disease. Until now, 11 patients have been reported. Herein, we report a 57-year-old man who had a neck mass that was incidentally found. Aspiration cytology and subsequent needle biopsy of the tumor were performed and suggested papillary thyroid carcinoma. From the resected specimen, however, the patient was finally diagnosed with parathyroid adenoma with prominent lymphocytic infiltrate, characterized by hyperplastic parathyroid cells with nuclear atypia within fibrotic stroma along with numerous lymphocytes forming germinal centers. Some eosinophils and plasma cells were also observed with some histological features highly suggestive of IgG4-related disease (IgG4-RD), including increased IgG4-positive plasma cells and IgG4/IgG-positive plasma cell ratio, storiform-type fibrosis, and obliterative phlebitis. It turned out that microfollicular or trabecular architecture and cellular atypia with high expression of HBME-1 observed in the aspiration cytology and needle biopsy had been misinterpreted as a thyroid malignancy. This is the first report describing microscopic features of aspiration cytology and needle biopsy of parathyroid adenoma with prominent lymphocytic infiltrate, warning that it can mimic papillary thyroid carcinoma in biopsy specimens. Furthermore, the IgG4-RD-like features of the present case and previous reports imply that parathyroid adenoma with prominent lymphocytic infiltrate may be a type of IgG4-RD.

Anterior hypopituitarism secondary to biopsy-proven IgG4-related hypophysitis in a young man

IgG4-related disease (IgG4-RD) is an immune-mediated fibro-inflammatory condition which can affect various organs including the pituitary gland. The true annual incidence of this condition remains widely unknown. In addition, it is unclear whether IgG4 antibodies are causative or the end result of a trigger. With no specific biomarkers available, the diagnosis of IgG4-related hypophysitis remains a challenge. Additionally, there is a wide differential diagnosis. We report a case of biopsy-proven IgG4-related hypophysitis in a young man with type 2 diabetes mellitus. Learning points: IgG4-related hypophysitis is part of a spectrum of IgG4-related diseases. Clinical manifestations result from anterior pituitary hormone deficiencies with or without diabetes insipidus, which can be temporary or permanent. A combination of clinical, radiological, serological and histological evidence with careful interpretation is required to make the diagnosis. Tissue biopsy remains the gold standard investigation. Disease monitoring and long-term management of this condition is a challenge as relapses occur frequently.

IgE Antibodies: From Structure to Function and Clinical Translation

Immunoglobulin E (IgE) antibodies are well known for their role in mediating allergic reactions, and their powerful effector functions activated through binding to Fc receptors FcεRI and FcεRII/CD23. Structural studies of IgE-Fc alone, and when bound to these receptors, surprisingly revealed not only an acutely bent Fc conformation, but also subtle allosteric communication between the two distant receptor-binding sites. The ability of IgE-Fc to undergo more extreme conformational changes emerged from structures of complexes with anti-IgE antibodies, including omalizumab, in clinical use for allergic disease; flexibility is clearly critical for IgE function, but may also be exploited by allosteric interference to inhibit IgE activity for therapeutic benefit. In contrast, the power of IgE may be harnessed to target cancer. Efforts to improve the effector functions of therapeutic antibodies for cancer have almost exclusively focussed on IgG1 and IgG4 subclasses, but IgE offers an extremely high affinity for FcεRI receptors on immune effector cells known to infiltrate solid tumours. Furthermore, while tumour-resident inhibitory Fc receptors can modulate the effector functions of IgG antibodies, no inhibitory IgE Fc receptors are known to exist. The development of tumour antigen-specific IgE antibodies may therefore provide an improved immune functional profile and enhanced anti-cancer efficacy. We describe proof-of-concept studies of IgE immunotherapies against solid tumours, including a range of in vitro and in vivo evaluations of efficacy and mechanisms of action, as well as ex vivo and in vivo safety studies. The first anti-cancer IgE antibody, MOv18, the clinical translation of which we discuss herein, has now reached clinical testing, offering great potential to direct this novel therapeutic modality against many other tumour-specific antigens. This review highlights how our understanding of IgE structure and function underpins these exciting clinical developments.

Resection of lesions in the ileum of patients with IgG4-related disease may ameliorate disease progression without steroid administration

Background

IgG4-related disease (IgG4-RD) is a pathological condition that is characterized by an infiltrate composed of IgG4-positive plasma cells and recently recognized as an immune-mediated condition. It causes tissue throughout the body to become stiff and thickened due to autoimmune reactions that cause fibrosis and scarring. Disease-related changes commonly occur in the salivary glands, bile duct, pancreas, and lungs, but are seldom seen in the small bowel. A diagnosis of IgG4-RD is suspected if a high level of IgG4 is found on a blood test. The ideal diagnostic method is pathological examination, but because the clinical manifestations of IgG4-RD are very diverse and nonspecific, the disease may often go undiagnosed until an unrelated biopsy or resection specimen is obtained. The most common treatment for IgG4-RD is steroid use. However, tapering or stopping steroid administration is seen to result in recurrence in approximately 50% of cases. A complete cure is therefore considered extremely difficult.

Case presentation

A 69-year-old man with gastrointestinal obstruction underwent small bowel resection for two lesions. On histopathological examination, the specimen showed features of IgG4-RD. We performed several tests to detect other characteristics of IgG4-RD, but were unable to find any. The patient is being followed up regularly for a year and is being observed for any symptoms of recurrence.

Conclusions

We present a case of IgG4-RD wherein the ileum wall was significantly sclerosed, leading to gastrointestinal tract obstruction; therefore, we resected two sections of the ileum. We believe that resection of IgG4-RD lesions can help avoid long-term steroid use in patients, because the surgery completely eliminates the pathological origins of the condition.

[Histological and clinical characteristics of cases of immunoglobulin G4-related disease in a tertiary hospital, in Cali, Colombia]

INTRODUCTION

Immunoglobulin G4 (IgG4)-related disease has been described in the last decade. It is a fibro-inflammatory condition capable of affecting almost every organ and diagnosis requires both clinical and paraclinical confirmation. We present the largest study to date in Colombia.

OBJECTIVE

To describe the clinical and histopathological characteristics of patients diagnosed with IgG4-related disease at the Fundación Valle del Lili.

METHODS

Observational-descriptive retrospective study. The clinical and pathological records of patients diagnosed with IgG4-related disease at the Fundación Valle del Lili were reviewed and a descriptive statistical analysis made.

RESULTS

From 2013-2016, 16 patients were diagnosed. Median age was 44 years (RIC 30-58) and 10 (62.5%) were women. The most common clinical presentation was a combination of a tumefactive mass, constitutional symptoms and site-related symptoms (43.8%) (n=7). No preference for any organ was seen. Histopathology revealed all cases had dense lymphoplasmacytic infiltrate and storiform-type fibrosis; 75% also had obliterative phlebitis. In all cases≥10 cells/HPF of IgG4+ were found and 81% had a ratio of IgG4+/IgG+>50%.

CONCLUSION

IgG4-related disease appears to be underdiagnosed, probably due to its broad clinical spectrum as well as a low index of awareness among clinicians. We recommend that, when dense lymphoplasmacytic infiltrates, storiform-type fibrosis or obliterative phlebitis are found, immunohistochemistry for IgG and IgG4should be requested. Positive results then must be correlated with complementary studies to confirm the disease.

Pancreatic Cytology

The diagnostic approach to pancreaticobiliary disease requires a multidisciplinary team in which the cytopathologist plays a crucial role. Fine-needle aspiration, obtained by endoscopic ultrasound, is the diagnostic test of choice for pancreatic lesions. Preoperative clinical management depends on many factors, many of which rely on accurate cytologic assessment. Pancreaticobiliary cytology is wrought with diagnostic pitfalls. Clinical history, imaging studies, cytology samples, and ancillary tests, including immunohistochemistry, biochemical analysis, and genetic sequencing, are integral to forming a complete diagnosis and guiding optimal patient management. This article reviews clinical aspects and the diagnostic work-up of commonly encountered diagnostic entities within the field of pancreatic cytology.

Immunohistochemical Biomarkers in Diagnosis of Hematolymphoid Neoplasms of Endocrine Organs

The hematolymphoid infiltrations are challenging lesions in endocrine organs and tissues. The fourth edition of WHO classification of tumors of endocrine organs and the fourth edition of WHO classification of tumors of hematopoietic and lymphoid tissues are recently published. The updates in both fields include some new disease descriptions and prognostic markers. Our aim in this review article is to give practical diagnostic information about the most frequently seen hematolymphoid involvements of the pituitary gland, thyroid, and adrenal tissue. We designed the text in the order of organs and the contents according to the disease frequency. The pituitary gland and cellar region are the most frequently involved with Langerhans cell histiocytosis. Although it is very rare, Erdheim-Chester disease has recently been included in the classification and still needs more clear diagnostic definitions. Lymphoproliferative thyroid lesions and presentations create diagnostic problems for the pathologists. IGG4-related disease and its relation with thyroiditis is a new concept. There are many unknowns on pathobiology of the disease spectrum and discussion on defined diagnostic criteria of the IGG4-related thyroid diseases. The overlapping features of thyroiditis and primary thyroid lymphomas also create diagnostic difficulties. The frequently recognized primary hematolymphoid lesions of the endocrine organs may not be difficult to diagnose since they are expected lesions. The secondary involvement of hematolymphoid neoplasia may be more difficult to diagnose for an endocrine pathologist. In this review article, we aim to give brief description of the diseases and practical diagnostic approach by using optimum markers guided by the latest WHO classifications.

Localised nasopharyngeal amyloidosis: the importance of postoperative follow-up

Localised nasopharyngeal amyloidosis is rare. Findings on physical examination and invasive pattern on CT scan can be misleading as it can resemble nasopharyngeal carcinoma. A 64-year-old man presented with left aural fullness for 6 months. The physical examination showed straw-coloured fluid in the left middle ear and irregular reddish mass at the left side of the nasopharynx. The CT scan showed a lobulated heterogeneous mass at the left side of the nasopharynx involving the left Eustachian tube opening. Pathology report was amyloidosis, thus, surgery was done. After a year, there were new foci of amyloidosis at the right side of the nasopharynx, and a repeat surgery was performed. Two years later, the systemic amyloidosis with underlying IgG4-related disease was suspected due to multiple organ involvement. Surgery is the treatment for localised amyloidosis with compressive symptoms. Close follow-up is important after surgical excision due to its recurrence and progression to systemic amyloidosis.