Study of systemic disease IgG4. Usefulness of 2-[18F]-fluoro-2-deoxy-D-glucose –positron emission tomography/computed tomography for staging, selection of biopsy site , evaluation of treatment response and follow-up

Abstract

Immunoglobulin G4-related systemic disease (IgG4-RSD) is a recently emerging disorder characterized by swelling lesions with storiform fibrosis and lymphoplasmacytic infiltration enriched with IgG4-positive plasma cells. IgG4-RSD has been found in multiple organs/ tissues. The diagnosis requires the integration of clinical, serological, imaging, histopathological, and immunohistological features. The 2-[18F]-fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (18F-FDG PET/CT) enables the acquisition of whole-body images and provides functional information about disease activity. However, its current role in IgG4-RSD is not well established in clinical practice. In our case, we studied a patient with systemic symptoms, submaxillary adenopathy, and imaging explorations that initially guided toward a lymphoproliferative process. However, the differential diagnosis with an autoimmune systemic disease type IgG4 was considered because of elevated levels of serum immunoglobulins. The study was completed with 18F-FDG PET/ CT that not only allowed us to assess the extension disease and to locate the best lesion for biopsy but also allowed us to evaluate the response to treatment and to diagnose the suspicion of recurrence. In this case, PET/CT shows its usefulness in clinical practice.

European Guideline on IgG4‐related digestive disease – UEG and SGF evidence‐based recommendations

“…Comments: IgG4‐related disease is a systemic condition with ≥2 organs involved in as much as 75% of patients in large case series 120–128 . Different organ involvement can occur at the same time or metachronously (for example, at relapse).…”

“…IgG4‐related disease is also frequently associated with enlarged lymph nodes, but the pathological relevance of isolated lymph node involvement in the absence of other characteristic IgG4‐related disease manifestations remains to be fully elucidated. Other localizations of IgG4‐related disease include: arteries (other than aorta), orbits, meninges, prostate, testicles, skin, nasal sinuses, mesentery, mediastinum, pericardium, pleura, peripheral nerves, bones, and muscles 120–122 , 124–128 , 130 . Based partly on organ involvement, four clinical phenotypes of IgG4‐related disease have been proposed: (a) pancreato‐hepato‐biliary disease; (b) retroperitoneal fibrosis and/or aortitis; (c) head and neck‐limited disease; and (d) classic Mikulicz syndrome with systemic involvement.…”

“…119 Comments: IgG4-related disease is a systemic condition with !2 organs involved in as much as 75% of patients in large case series. [120][121][122][123][124][125][126][127][128] Different organ involvement can occur at the same time or metachronously (for example, at relapse). The patient's history should be screened cautiously, as previous medical issues often reveal unrecognized manifestations of this condition.…”

“…Other localizations of IgG4-related disease include: arteries (other than aorta), orbits, meninges, prostate, testicles, skin, nasal sinuses, mesentery, mediastinum, pericardium, pleura, peripheral nerves, bones, and muscles. [120][121][122][124][125][126][127][128]130 Based partly on organ involvement, four clinical phenotypes of IgG4-related disease have been proposed: (a) pancreato-hepato-biliary disease; (b) retroperitoneal fibrosis and/or aortitis; (c) head and neck-limited disease; and (d) classic Mikulicz syndrome with systemic involvement. There is considerable overlap in several of these proposed phenotypes, however, and the biological basis (and ultimate validity) of the proposed phenotypes is not clear.…”

European Guideline on IgG4-related digestive disease: UEG and SGF evidence-based recommendations

“…(GRADE 1A; strong agreement) Comments: IgG4-related disease is a systemic condition with !2 organs involved in as much as 75% of patients in large case series. [120][121][122][123][124][125][126][127][128] Different organ involvement can occur at the same time or metachronously (for example, at relapse). The patient's history should be screened cautiously, as previous medical issues often reveal unrecognized manifestations of this condition.…”