IgG4-Related Disease of the Central Nervous System: A Case Series.

IgG4-related disease (IgG4-RD) is a rare and often misdiagnosed disorder with limited literature that highlights the different neurological presentations of this treatable disease. The diagnosis of IgG4-RD could be challenging, while imaging is fundamental for the diagnosis, biopsy is considered the gold standard. Most cases respond well to steroids and immunosuppressive therapy.

Radioactive Iodine Therapy in Differentiated Thyroid Cancer: 2020 Update.

The paradigm of theranostics is based on tailoring therapy for the purpose of optimizing outcomes. This principle is being applied to radioactive iodine therapy. Consequently, thyroid cancer therapy protocols are evolving.

Primary Thyroid Lymphoma: External Beam Radiation Therapy Induced Thyroiditis Mimics Residual Disease on Serial F-FDG PET/CT Imaging.

A 67-year-old female patient with no prior history of benign thyroid disease was diagnosed with primary thyroid lymphoma and was staged with F-fluoro-2-deoxy-D-glucose (F-FDG) positron emission tomography/computed tomography (PET/CT). She was treated with chemotherapy and external beam radiation therapy, and a follow-up PET/CT showed significant reduction in the size of the thyroid lymphoma with persistent intense F-FDG uptake, which was interpreted as partial response to therapy. However, two subsequent PET/CT studies showed no change in the persistent intense F-FDG uptake in the thyroid and a biopsy confirmed the presence of thyroiditis with no evidence of residual lymphoma.

Inflammatory and Ischemic Post Liver Transplant Complications Mimic Malignancy on F-FDG PET/CT.

A 65-year-old male patient with a one year history of liver transplantation was referred for an F-fluoro-2-deoxy-D-glucose (F-FDG) positron emission tomography/computed tomography (PET/CT) to rule out post transplant lymphoproliferative disease. Multiple foci of intense abnormal F-FDG uptake were seen in the transplanted liver which were concerning for malignancy. Explantation of the liver approximately 1 month following the PET/CT revealed multiple inflammatory and ischemic changes including large bile duct necrosis, acute cholangitis, bile duct obstruction changes and periportal fibrosis, with no evidence of malignancy.

Systemic Lupus Erythematosus Associated Pitfalls on F-FDG PET/CT: Reactive Follicular Hyperplasia, Kikuchi-Fujimoto Disease, Inflammation and Lymphoid Hyperplasia of the Spleen Mimicking Lymphoma.

Systemic lupus erythematosus (SLE) is associated with a variety of inflammatory processes that can affect the lymph nodes, brain, kidneys, and spleen. We present two patients with SLE in whom SLE-associated conditions complicated interpretation of F-fluoro-2-deoxy-d-glucose (F-FDG) positron emission tomography/computed tomography (PET/CT) imaging of the lymph nodes and the spleen. The imaging findings mimicked lymphoma, but histopathological evaluation showed benign processes including reactive follicular hyperplasia in the lymph nodes, Kikuchi-Fujimoto disease in perisplenic lymph nodes, and inflammatory changes and lymphoid hyperplasia in the spleen.

Thyroid Incidentalomas on F-FDG PET/CT: Clinical Significance and Controversies.

Objective: The purpose of the current study is to examine the incidence and clinical significance of unexpected focal uptake of F-fluorodeoxyglucose (F-FDG) on positron emission tomography/computed tomography (PET/CT) in the thyroid gland of oncology patients, the maximum standardized uptake value (SUV) of benign and malignant thyroid incidentalomas in these patients, and review the literature.

Methods: Seven thousand two hundred fifty-two F-FDG PET/CT studies performed over four years, were retrospectively reviewed. Studies with incidental focal F-FDG uptake in the thyroid gland were further analyzed.

Composite Cutaneous Lymphoma (Iatrogenic Immunodeficiency-Associated Lymphoproliferative Disorder) in a Patient with Rheumatoid Arthritis Treated with Methotrexate: Staging and Evaluation of Response to Therapy with F-FDG PET/CT.

A 67 year old woman with a 10 year history of rheumatoid arthritis (RA) treated with methotrexate and prednisone, presented with a 2 year history of worsening multiple cutaneous plaques of variable appearance. Two distinct skin lesions were biopsied to reveal a composite cutaneous lymphoma, possibly caused by long term methotrexate therapy. An [18F] fluoro-2-deoxy-D-glucose (F-FDG) positron emission tomography/computed tomography (PET/CT) was performed to stage the malignancy, and was later repeated to evaluate response to chemotherapy, which guided subsequent management.

Clinical Significance of F-Fluorodeoxyglucose Avid Prostate Gland Incidentalomas on Positron Emission Tomography/Computed Tomography.

Objective: The aim of this study was to evaluate the clinical significance of incidental focal uptake of F-fluorodeoxyglucose (F-FDG) on positron emission tomography/computed tomography (PET/CT) in the prostate glands of cancer patients.

Methods: A retrospective review of 3122 consecutive male patients who underwent F-FDG PET/CT studies with an oncologic indication, over the course of four years, was performed. Studies with incidental F-FDG uptake in the prostate gland were further analyzed.

Follicular lymphoma transforming into diffuse large B-cell lymphoma in spleen: Simultaneous appearance of both on F-FDG PET/CT and histology.

Low grade lymphoma may transform into a more aggressive lymphoma and this transformation is usually associated with a poor outcome. A 65year old man presented with two metabolically active splenic lesions on a staging [18F] fluoro-2-deoxy-d-glucose (F-FDG) positron emission tomography/computed tomography (PET/CT). Histologic evaluation post splenectomy confirmed the presence of two clonally related lymphomas: a follicular lymphoma (FL) and a diffuse large B-cell lymphoma (DLBCL).

Comparison of Prostate-Specific Membrane Antigen-Based 18F-DCFBC PET/CT to Conventional Imaging Modalities for Detection of Hormone-Naïve and Castration-Resistant Metastatic Prostate Cancer.

Unlabelled: Conventional imaging modalities (CIMs) have limited sensitivity and specificity for detection of metastatic prostate cancer. We examined the potential of a first-in-class radiofluorinated small-molecule inhibitor of prostate-specific membrane antigen (PSMA), N-[N-[(S)-1,3-dicarboxypropyl]carbamoyl]-4-(18)F-fluorobenzyl-l-cysteine ((18)F-DCFBC), to detect metastatic hormone-naïve (HNPC) and castration-resistant prostate cancer (CRPC).

Methods: Seventeen patients were prospectively enrolled (9 HNPC and 8 CRPC); 16 had CIM evidence of new or progressive metastatic prostate cancer and 1 had high clinical suspicion of metastatic disease.

Clinical significance of parotid gland incidentalomas on (18)F-FDG PET/CT.

The aim of this study was to evaluate the frequency and clinical significance of incidental focal uptake of (18)F-fluorodeoxyglucose (FDG) on positron emission tomography/computed tomography (PET/CT) in the parotid glands of cancer patients. A retrospective review of 7,252 oncologic PET/CT studies was done. FDG positive parotid incidentalomas occurred in 0.

Value of Fluorodeoxyglucose PET/Computed Tomography Patient Management and Outcomes in Thyroid Cancer.

"Fluorodeoxyglucose (FDG) PET/computed tomography (CT) is used most frequently in the surveillance of iodine-refractory differentiated thyroid cancer with increased thyroglobulin level after therapy. This article evaluates the impact of FDG-PET/CT on clinical management and the prognostic implications of a positive scan. In the studies reviewed, FDG-PET/CT changed the course of management in 14% to 78% of patients with suspected recurrence, and a positive scan was associated with poorer survival.

Head and neck PET/CT: therapy response interpretation criteria (Hopkins Criteria)-interreader reliability, accuracy, and survival outcomes.

Unlabelled: There has been no established qualitative system of interpretation for therapy response assessment using PET/CT for head and neck cancers. The objective of this study was to validate the Hopkins interpretation system to assess therapy response and survival outcome in head and neck squamous cell cancer patients (HNSCC).

Methods: The study included 214 biopsy-proven HNSCC patients who underwent a posttherapy PET/CT study, between 5 and 24 wk after completion of treatment.

Gastric neuroendocrine carcinoma staged and followed with (18)F-FDG PET/CT--a report of 3 cases.

Gastric neuroendocrine carcinomas (NEC) are very rare, aggressive tumors of the stomach that are distinct from the more benign neuroendocrine tumors, sometimes referred to as "gastric carcinoids." We present 3 cases of gastric NEC representing various histological subtypes that were successfully staged and followed with F-FDG PET/CT, impacting therapeutic management in each case.

Infectious and inflammatory complications of surgical management of cancer patients imaged with 18F-FDG PET/CT: a pictorial essay.

The aim of this pictorial essay was to highlight the usefulness of fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in evaluating incidental infection or inflammation in cancer patients, related to surgical management. A retrospective review of 10,985 consecutive oncologic PET/CTs was done, and nine cases with suspected FDG positive infectious or inflammatory processes were selected for further review. PET/CT helped identify infections and inflammatory processes related to surgical management of cancer patients, define the extent of infection or inflammation, guide the management and, in some cases, evaluate response to therapy.

Spectrum of malignant renal and urinary bladder tumors on 18F-FDG PET/CT: a pictorial essay.

A wide variety of malignant renal and urinary bladder diseases can be detected on (18)F-FDG PET/CT. Although the PET/CT findings are often nonspecific, the aim of this atlas was to demonstrate that the spectrum of renal and urinary bladder malignancy that can be evaluated with PET/CT is much broader than current medical literature would suggest. PET/CT readers and oncologists should be aware of the variety of urological tumor types that can be detected on PET/CT and some of the patterns of (18)F-FDG uptake that can be observed in these cases.

Spectrum of gastric malignancy on 18F-FDG PET/CT: a pictorial essay.

A wide variety of malignant gastric diseases can be detected, staged, and followed on (18)F-FDG PET/CT. Although the PET/CT findings are often nonspecific and some can be seen in certain benign gastric diseases, the aim of this atlas was to demonstrate that the wide histological spectrum of gastric tumors that can be evaluated, staged, and followed with PET/CT is much broader than current medical literature would suggest. PET/CT readers and oncologists should be aware of the utility of PET/CT in these tumors and the imaging characteristics and patterns of (18)F-FDG uptake that can be demonstrated in these cases.

Spectrum of malignant pleural and pericardial disease on FDG PET/CT.

Objective: The purpose of this article is to illustrate a wide spectrum of malignant primary and secondary pleural and pericardial diseases imaged with (18)F-FDG PET/CT.

Conclusion: A wide variety of malignant pleural and pericardial diseases can be detected, staged, and monitored by FDG PET/CT. Although the PET/CT findings are often nonspecific, the aim of this atlas is to show that the spectrum of pleural and pericardial disease that can be evaluated with PET/CT is much broader than current literature would suggest.

Lung Adenocarcinoma Staged as an Unknown Primary Presenting with Symptomatic Colon Metastases: Staging by 18F-FDG PET/CT.

A 66-year-old man, who presented with bright red blood per rectum, was referred for an (18)F-FDG PET/CT after colonoscopy showed two suspicious colon masses, which were biopsied to reveal an adenocarcinoma of unknown origin. PET/CT showed two intensely FDG-avid colon masses as well as an unsuspected FDG-avid lung mass, which was biopsied to reveal a primary lung adenocarcinoma. Immunohistochemistry confirmed the two colon metastases were of pulmonary origin.

Incidental Bilateral Renal Oncocytoma in a Patient with Metastatic Carcinoma of Unknown Primary: a Pitfall on (18)F-FDG PET/CT.

Bilateral renal masses are uncommon but can raise a strong suspicion of primary or secondary malignancy, especially during the initial work-up of an oncology patient. Renal oncocytomas are benign renal tumors that are commonly discovered incidentally on diagnostic imaging with a small percentage occurring bilaterally. Although (18)F-FDG uptake in renal oncocytomas has been described, a case of a bilateral (18)F-FDG-avid renal oncocytoma has not been previously reported in the literature.

Plasmablastic lymphoma of the oral cavity in an HIV-positive patient: staging with 18F-FDG PET/CT.

Plasmablastic lymphoma of the oral cavity is a very rare and only recently recognized entity that has been identified almost exclusively in HIV-infected individuals. It has a predilection for the oral cavity, often exhibits very aggressive behavior and has a poor prognosis. The use of 18F-FDG PET/CT in the evaluation of HIV-associated lymphomas is a recent development, and its use in the staging of plasmablastic lymphoma of the oral cavity has not been previously reported.