F-18 FDG PET-CT findings in Mikulicz disease and systemic involvement of IgG4-related lesions. Clin Nucl Med. 2009;34:164-167. [PMID: 19352281 DOI: 10.1097/rlu.0b013e3181967568]

Features of IgG4-related lung disease on 18F-FDG PET/computed tomography imaging

OBJECTIVES

The aim of the study was to summarize the features of immunoglobulin G4-related lung disease (IgG4-RLD) on fluorine 18-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT).

METHODS

In this retrospective case series, 12 consecutive patients (9 men and 3 women, mean age 55.4 ± 13.7 years) with IgG4-RLD were included. The clinicopathological information and features of F-FDG PET/CT imaging were analyzed.

RESULTS

Six (50%) patients had pulmonary involvement alone and six (50%) patients had extrapulmonary involvement with intense F-FDG uptake. Pulmonary manifestations included mass (25%, 3/12), solid nodule (solitary 25%, 3/12; multiple 50%, 6/12), multiple ground-glass opacities (GGOs) (50%, 6/12), thickening of alveolar interstitium (50%, 6/12), and thickening of bronchovascular bundle (33.3%, 4/12). The maximum standardized uptake value (SUVmax) of the solid nodules and masses, multiple GGOs, bronchovascular bundle and the thickening of septa was 4.0 ± 2.5, 2.3 ± 1.8, 1.4 ± 0.6, and 0.9 ± 0.5, respectively. The SUVmax statistically significant linear association with the diameter of masses or solid nodules (P value = 0.03), but no significant inverse linear association (P value = 0.06) with the concentration of serum IgG4 concentration.

CONCLUSIONS

The image patterns of IgG4-RLD on F-FDG PET/CT are varying. Multiple pulmonary manifestations or multiple organ involvement, especially in combination with elevated levels of serum IgG and IgG4, may help to make the diagnosis. A potential major application of PET-CT would be evaluation of response to treatment, and the impact of PET/CT on IgG4-RLD management is worth investigating further in the future.

Gallium SPECT/CT in evaluation of IgG4-related disease: A case report and literature review

BACKGROUND

The clinical picture of IgG4-related sclerosing disease (IgG4-RSD) may mimic lymphoma, and should be in the differential diagnosis of patients with this clinical picture.

CASE SUMMARY

A 32-year-old female had recurrent swelling of both eyelids for more than 15 years. Examination revealed elastic, firm, swollen lacrimal glands about 2-3 cm in diameter that was not painful. Head and orbits magnetic resonance imaging (MRI) showed mass lesions over the bilateral lacrimal glands, submandibular glands, and left foramen of ovale. The differential diagnosis included lymphoid tissue, inflammatory masses, and lymphoma. Gallium single-photon emission computed tomography/computed tomography (SPECT/CT) showed uptake in the bilateral lacrimal glands, right parotid and bilateral submandibular glands, bilateral perirenal region, mediastinal, prevertebral, paraaortic, lumbar, bilateral pelvic (including internal iliac chain) lymph nodes, anterior aspect of right 3rd rib, and lateral aspect of left 6th rib. CT showed multiple enlarged lymph nodes in the mediastinum, right pulmonary hilum, prevertebral space of the thoracolumbar spine, retroperitoneal paraaortic area, bilateral parailiac areas, and bilateral perirenal spaces. Antinuclear and anti-SSA/SSB antibodies were negative, and the serum IgG4 level was 740 mg/dL (normal, 8-140 mg/dL). Right parotid gland biopsy showed abundant IgG4-positive plasma cells. Mikulicz disease (IgG4-related sclerosing disease) was diagnosed and she received glucocorticoid treatment. Follow-up CT and MRI showed with resolved eyelid swelling and perirenal mass lesions. Follow-up gallium scan was normal.

CONCLUSION

Gallium SPECT/CT can be a useful tool for initial and follow-up evaluation of IgG4-RSD.

A rare and emerging entity: Sinonasal IgG4-related sclerosing disease

BACKGROUND

Immunoglobulin G4 (IgG4) related sclerosing disease (rSD) is a new disease entity, first described in 2001, that involves autoimmune pancreatitis. Considered a systemic disease with lesions described in multiple organ systems, IgG4-rSD that affects the sinonasal region is rare. Our goal was to highlight the sinonasal presentation of this unique disease and to review previously reported adult cases from 2003 to 2014.

METHODS

Case report (a 72-year-old man who presented with left exophthalmos, periorbital pain, and epiphora) and review of the literature.

RESULTS

Radiographic workup with computed tomography and magnetic resonance imaging demonstrated a left sinonasal mass that involved the left maxillary and ethmoid sinuses, with surrounding bony destruction and orbital invasion. Nasal endoscopy demonstrated a fibrous lesion emanating in the middle meatus, with surrounding mucosal inflammation. The patient underwent an endoscopic biopsy, medial maxillectomy, and ethmoidectomy with tumor debulking. Pathology demonstrated inflamed respiratory mucosa with dense lymphoplasmacytic infiltrate and fibrosis; flow cytometry demonstrated no malignant cell populations; immunophenotyping demonstrated multiple foci of IgG4 cells. Plasma IgG4 was elevated in the setting of normal total IgG. The patient was treated with postoperative systemic and topical corticosteroids. Surveillance imaging studies and nasal endoscopy demonstrated disease resolution without recurrence.

CONCLUSIONS

Sinonasal IgG4-rSD is a rare disease that can present with bony and soft-tissue invasion. This was an exceptional case, with osseous involvement and orbital invasion. Immunohistologic workup is essential for diagnosis. It is important to differentiate this disease from sinonasal tumors. Treatment includes corticosteroids and surgical debulking. Sinonasal IgG4-rSD represents an emerging disease that may present challenges for future rhinologists.

Contrast-enhanced (18)F-fluorodeoxyglucose positron emission tomography/computed tomography in immunoglobulin G4-related retroperitoneal fibrosis

Immunoglobulin G4 (IgG4)-related disease encompasses a wide variety of immune disorders previously thought be distinct. IgG4-related retroperitoneal fibrosis is one such entity. Metabolic imaging with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) can be useful in the management of IgG4-related retroperitoneal fibrosis. We here discuss the case of 63-year-old male with IgG4-related retroperitoneal fibrosis and the role, ¹⁸F-FDG PET/CT played in his management.

Autoimmune pancreatitis in the context of IgG4-related disease: Review of imaging findings

Current understanding of autoimmune pancreatitis (AIP) recognizes a histopathological subtype of the disease to fall within the spectrum of IgG4-related disease. Along with clinical, laboratory, and histopathological data, imaging plays an important role in the diagnosis and management of AIP, and more broadly, within the spectrum of IgG4-related disease. In addition to the defined role of imaging in consensus diagnostic protocols, an array of imaging modalities can provide complementary data to address specific clinical concerns. These include contrast-enhanced computed tomography (CT) and magnetic resonance (MR) imaging for pancreatic parenchymal lesion localization and characterization, endoscopic retrograde and magnetic resonance cholangiopancreatography (ERCP and MRCP) to assess for duct involvement, and more recently, positron emission tomography (PET) imaging to assess for extra-pancreatic sites of involvement. While the imaging appearance of AIP varies widely, certain imaging features are more likely to represent AIP than alternate diagnoses, such as pancreatic cancer. While nonspecific, imaging findings which favor a diagnosis of AIP rather than pancreatic cancer include: delayed enhancement of affected pancreas, mild dilatation of the main pancreatic duct over a long segment, the “capsule” and “penetrating duct” signs, and responsiveness to corticosteroid therapy. Systemic, extra-pancreatic sites of involvement are also often seen in AIP and IgG4-related disease, and typically respond to corticosteroid therapy. Imaging by CT, MR, and PET also play a role in the diagnosis and monitoring after treatment of involved sites.

An atypical case of IgG4-related sclerosing pancreatitis on PET/CT imaging

A 62-year-old man presented with pain in the upper abdomen persisting for 2 months. He had the clinical history of diabetes for approximately 10 years. CT and MRI showed a mass located in processus uncinatus of caput pancreatis. The laboratory tests, including pancreas-originated amylase, tumor marker, IgG, IgG4, and so on, were normal. For suspicion of pancreatic cancer, the patient underwent F-FDG PET/CT, which demonstrated focal and high radioactivity accumulation in processus uncinatus of pancreas, without extrapancreatic radioactivity uptake observed. Finally, the surgical pathology confirmed IgG4-related sclerosing pancreatitis.

Characterizing IgG4-related disease with ¹⁸F-FDG PET/CT: a prospective cohort study

Purpose

IgG4-related disease (IgG4-RD) is an increasingly recognized clinicopathological disorder with immune-mediated inflammatory lesions mimicking malignancies. A cohort study was prospectively designed to investigate the value of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in characterizing IgG4-RD.

Methods

Thirty-five patients diagnosed with IgG4-RD according to the consensus criteria were enrolled with informed consent. All patients underwent baseline ¹⁸F-FDG PET/CT evaluation. Among them, 29 patients underwent a second ¹⁸F-FDG PET/CT scan after 2 to 4 weeks of steroid-based therapy.

Results

All 35 patients were found with ¹⁸F-FDG-avid hypermetabolic lesion(s); 97.1 % (34/35) of these patients showed multi-organ involvement. Among the 35 patients, 71.4 % (25/35) patients were found with more organ involvement on ¹⁸F-FDG PET/CT than conventional evaluations including physical examination, ultrasonography, and computed tomography (CT). ¹⁸F-FDG PET/CT demonstrated specific image characteristics and pattern of IgG4-RD, including diffusely elevated ¹⁸F-FDG uptake in the pancreas and salivary glands, patchy lesions in the retroperitoneal region and vascular wall, and multi-organ involvement that cannot be interpreted as metastasis. Comprehensive understanding of all involvement aided the biopsy-site selection in seven patients and the recanalization of ureteral obstruction in five patients. After 2 to 4 weeks of steroid-based therapy at 40 mg to 50 mg prednisone per day, 72.4 % (21/29) of the patients showed complete remission, whereas the others exhibited > 81.8 % decrease in ¹⁸F-FDG uptake.

Conclusion

F-FDG PET/CT is a useful tool for assessing organ involvement, monitoring therapeutic response, and guiding interventional treatment of IgG4-RD. The image pattern is suggested to be updated into the consensus diagnostic criteria for IgG4-RD.

Usefulness of 2-[18F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography for staging and evaluation of treatment response in IgG4-related disease: a retrospective multicenter study

OBJECTIVE

To evaluate the usefulness of 2-[18F]-fluoro-2-deoxy-d-glucose-positron emission tomography/computed tomography (FDG-PET/CT) in IgG4-related disease (IgG4-RD) for the staging of the disease and the followup under treatment.

METHODS

All patients included in the French IgG4-RD registry who underwent ≥1 FDG-PET/CT scan were included in the study. Clinical, biologic, pathologic, radiologic, and FDG-PET/CT qualitative and quantitative findings were retrospectively collected and analyzed.

RESULTS

Twenty-one patients were included in the study and 46 FDG-PET/CT examinations were evaluated. At either diagnosis or relapse, all evaluated patients presented abnormal 18F-FDG uptake in typical IgG4-RD localizations. In most cases, FDG-PET/CT was more sensitive than conventional imaging to detect organ involvement, especially in arteries, salivary glands, and lymph nodes. In few cases (small-sized lesions and brain or kidney contiguous lesions), false-negative results were noted. Evaluation before and after treatment showed in most cases a good correlation of FDG-PET/CT results with treatment response and disease activity.

CONCLUSION

This large retrospective study shows that FDG-PET/CT imaging is useful for the staging of IgG4-RD. Moreover, FDG-PET/CT is useful to assess the response to treatment during followup.

IgG4-related disease of the head and neck: CT and MR imaging manifestations

Immunoglobulin G4 (IgG4)-related disease is a recently established systemic disease that commonly involves the head and neck, including the salivary glands, lacrimal glands, orbits, thyroid gland, lymph nodes, sinonasal cavities, pituitary gland, and larynx. Although the definitive diagnosis of IgG4-related disease requires histopathologic analysis, elevated serum IgG4 levels are helpful in making the diagnosis. Because of the proposed clinical diagnostic criteria for this disease, cross-sectional imaging modalities such as computed tomography (CT) and magnetic resonance (MR) imaging play an important diagnostic role. CT and MR imaging findings of IgG4-related disease are usually nonspecific. At CT, involved organs may demonstrate enlargement or decreased attenuation; at T2-weighted MR imaging, they may have relatively low signal intensity owing to their increased cellularity and amount of fibrosis. Some pathologic entities involving the head and neck are now considered to be part of the IgG4-related disease spectrum, including idiopathic orbital inflammatory syndrome (inflammatory pseudotumor), orbital lymphoid hyperplasia, Mikulicz disease, Küttner tumor, Hashimoto thyroiditis, Riedel thyroiditis, and pituitary hypophysitis. Because involvement of multiple sites is common in IgG4-related disease, radiologists should be familiar with manifestations of this systemic process outside the head and neck, in organs such as the pancreas, bile ducts, gallbladder, kidneys, retroperitoneum, mesentery, lungs, gastrointestinal tract, and blood vessels. Moreover, IgG4-related disease usually demonstrates a dramatic response to corticosteroid therapy, and radiologists should be familiar with its clinical and imaging manifestations to avoid a delay in diagnosis or unnecessary invasive interventions.

Systemic IgG4-related sclerosing disease: spectrum of imaging findings and differential diagnosis

OBJECTIVE

The purposes of this article are to provide a practical review of the spectrum of imaging findings in patients with systemic IgG4-related sclerosing disease and to address the differential diagnoses.

CONCLUSION

IgG4-related sclerosing disease is a systemic disorder that can involve almost any organ. The imaging findings consist of diffuse and focal organ infiltration and encasement by inflammatory and fibrotic tissue. Awareness of the spectrum of imaging findings in IgG4-related disease should prompt further evaluation for systemic manifestations to avoid misdiagnosis.

Conjunctival lymphoma can be detected by FDG PET

Four consecutive patients presented with extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) in the conjunctiva. After the initial resection, long-term follow-up without additional therapy showed the clinical relapse. Fluorodeoxyglucose positron emission tomography fused with computed tomography (PET/CT) showed abnormal uptake in the conjunctival relapsed lesions, which were, on reresection, again proven as MALT lymphoma. Small and thin lesions of MALT lymphoma in the conjunctiva can be detected by fluorodeoxyglucose PET/CT. The resolution of PET/CT, delineated in this study, could be applied to the other areas of the body to achieve more accurate staging of lymphoma.

[IgG4-related systemic disease: emergence of a new systemic disease? Literature review]

Hyper-IgG4 syndrome, or IgG4-related systemic disease (IgG4-RSD), has been recently characterized by the association of a focal or diffuse enlargement in one or more organs, elevated levels of serum IgG4 and histopathological findings including "storiform" fibrosis and prominent infiltration of lymphocytes and IgG4-positive plasma cells. Pancreas was the first organ involved with sclerosing pancreatitis (or autoimmune pancreatitis). Since this first description, many extrapancreatic lesions have been described, even in the absence of pancreatitis and include sialadenitis, lacrimal gland inflammation, lymphadenopathy, aortitis, sclerosing cholangitis, tubulointerstitial nephritis, retroperitoneal fibrosis or inflammatory pseudotumors. Multiorgan lesions can occur synchronously or metachronously in a same patient, usually after 50 years of age. They all share common histopathological findings. The disease often responds well to corticosteroid therapy. In this literature review on IgG4-RSD, we present historical, epidemiological and clinical characteristics, and we review the biological and histological diagnostic criteria. To date there is no international validated diagnostic criteria. Pathophysiological hypothesis and therapeutic approaches are also discussed.

Immunoglobulin G4 (IgG4)-positive or -negative ocular adnexal benign lymphoid lesions in relation to systemic involvement

The purpose of this study is to determine the relationship of ocular adnexal benign or reactive lymphoid hyperplasia, including orbital pseudotumor, with immunoglobulin G4 (IgG4)-related diseases. Medical charts of 9 consecutive patients with ocular adnexal benign lymphoid lesions, seen in the Department of Ophthalmology, Okayama University Hospital, were reviewed, and pathological sections were restained immunohistochemically for IgG4-, IgG-, and CD138-positive plasma cells. The diagnosis of IgG4-positive lesions was based on 10 or more IgG4-positive plasma cells in a high-power field and greater than 40% ratios of IgG4-positive plasma cells/CD138-positive plasma cells and IgG4-positive plasma cells/IgG-positive plasma cells. IgG4-positive lesions were determined as absent in 5 patients (4 with bilateral lacrimal/orbital lesions and one with a unilateral conjunctival lesion), none of whom showed systemic manifestations. In contrast, IgG4-positive lesions were present in 4 patients (3 with bilateral lacrimal/orbital lesions and one with a unilateral lacrimal/orbital lesion), who showed systemic manifestations : one with Hashimoto thyroiditis, one with IgG4-positive bilateral interstitial lung disease and hepatic inflammatory pseudotumor, one with bilateral interstitial lung disease, and one with systemic lymphadenopathy and antiphospholipid syndrome. In conclusion, IgG4-positive ocular adnexal benign lymphoid lesions might be used as a benchmark for the probable presence of other systemic lymphoid lesions.