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This study aimed to see the impact of FDG PET/CT with somatostatin receptor PET (SSTR PET) in directing the treatment plan in lower-grade well-differentiated neuroendocrine tumors (NETs) with Ki67 index ≤5%.Sixty-three NET cases with Ki67 index ≤5% with both FDG PET and SSTR PET ( 68 Ga-DOTANOC PET) were included for this retrospective observational study. FDG PET findings were classified into positive, weakly positive, and negative based on a visual scale. Clinical factors considered while referring for FDG PET scan were audited from electronic medical records. The addition of chemotherapy was considered as FDG-directed change in treatment.Sixty patients showed intense SSTR expression in the primary and metastatic sites (if present). Three patients showed no evidence of SSTR expression, in whom the scans were done after resection of the primary tumor. The FDG PET was positive in 25 (39.6%), weakly positive in 11 (17.4%), and negative in 27 (42.8%). Specific clinical reason for doing FDG PET was found in 34 patients, and in the remaining 29, there was no justification or specific indication for doing the FDG study; 73.5% of patients from the former group was either FDG positive or weakly positive, and 26.5% were negative; in the other group, 62.1% were FDG-negative, and 37.9% were positive ( P = 0.004). Treatment-naive patients with symptom duration of ≤5 months were associated with more FDG positivity than patients with5 months' symptom duration ( P = 0.006). FDG PET/CT led to change in management in 17.4% of all the patients, 9.6% of grade 1, and 25% of grade 2 patients.In lower-grade NET, FDG positivity was seen in a sizable number of the cases, and this led to change in management in 17.4% of the cases. Specific clinical features could be utilized to successfully discriminate between FDG-avid and non-FDG-avid disease in lower-grade NETs, and this had impact in management change as well.

Sporadic cerebellar hemangioblastomas are rare with majority of these tumors presenting as a part of von Hippel-Lindau syndrome. We demonstrate an unusual case of a symptomatic sporadic cerebellar hemangioblastoma mimicking a meningioma on MRI and 68 Ga-DOTANOC PET imaging.

The incidence of congenital melanocytic nevi (CMNs) is 1% to 6% for small- to intermediate-size nevi to 1 in 500,000 for giant size nevi. Large and satellite CMNs are known to be associated with neurocutaneous melanosis and central nervous system malformations such as Dandy-Walker malformation, defects of the vertebra-skull, and intraspinal lipomas. We hereby present a case of CMN syndrome in an 18-year-old girl with leptomeningeal melanoma, evaluated with MRI, adequately staged, and screened with FDG PET.

We present the findings of 18 F-FDG PET and 68 Ga-fibroblast activation protein PET scans done in a case of bilateral breast carcinoma with 2 different histopathology, left breast tubulolobular carcinoma and right breast invasive breast carcinoma of no special type.

Spindle cell sarcoma is a connective tissue tumor usually involving bone or muscle. Penis is an unusual and very rare site for the primary involvement of the tumor, especially mesenchymal tumor. We here present a case of a 27-year-old man diagnosed with spindle cell sarcoma of penile origin in which FDG PET/CT was done as part of workup.

Delayed-onset radiation-induced myelitis is a rare but serious complication of radiation exposure to the spinal cord. In this report, we describe the 18 F-FDG PET/CT findings of radiation-induced myelitis in a patient with carcinoma of buccal mucosa treated with external beam radiotherapy.

Carcinoma of breast with neuroendocrine differentiation is an extremely rare entity, especially in male population. Although the "garden variety" of male breast cancers is often metastatic at presentation, with an aggressive course, there is hardly any literature about neuroendocrine variants. We report a case of a 57-year-old man who had pituitary symptoms, which on 68Ga-DOTANOC PET/CT imaging turned out to be a metastatic lesion, with somatostatin expressing primary in breast and other sites, with histopathological confirmation of neuroendocrine differentiation in breast cancer.

Mantle cell lymphoma is a rare and aggressive non-Hodgkin lymphoma with a high propensity for extranodal involvement, typically seen in the liver, marrow, and gastrointestinal system. Being an FDG-avid disease and a sensitive modality for detecting both nodal and extranodal disease, FDG PET/CT is recommended in the workup of mantle cell lymphoma. We present a rare pattern of cutaneous involvement of the head-neck region in a patient with mantle cell lymphoma, which can be described on FDG PET/CT as a "hood sign."

68 Ga-PSMA PET/CT is one of the most common imaging uses for prostate cancer imaging. Although initially thought to be specific for prostate cancer, there are many evidences that are coming of its concentration in many other neoplastic and nonneoplastic pathologies. Helicobacter pylori is the most common bacteria causing gastric inflammation and usually presents with gastroduodenal ulcer. Here we present one unusual case of benign gastric mass formation caused by H. pylori infection with PSMA concentration.

Medulloblastomas, especially the sonic hedgehog subgroup, are treated aggressively with surgery and chemoradiotherapy, as they are associated with high local site recurrence rate and poor overall survival. Radiation-induced meningioma is the most common delayed complication of craniospinal irradiation. This needs to be differentiated from meningeal or ependymal metastases as the later need aggressive management. We report one such rare case, in a patient who completed treatment for medulloblastoma 11 years ago, was in remission, and now presented with dural-based lesions.

Sunitinib is one of the most commonly used multikinase inhibitors for metastatic renal cell carcinoma. Myositis is one of the rarest known adverse effects of sunitinib. Presenting herewith one such case with its relevant imaging findings on FDG PET/CT and ultrasound.

Introduction The event-free survival in pediatric anaplastic large cell lymphoma (ALCL) remains at 70% irrespective of the diverse chemotherapy regimens used. There is lack of valid prognostic factors identifying high-risk patients. We investigated the prognostic value of baseline metabolic parameters and interim response on F-FDG PET/CT in pediatric ALCL patients. Methods We retrospectively reviewed 40 pediatric ALCL patients with paired F-FDG PET/CT and treated uniformly on vinblastine-based institution protocol. The SUVmax, SUVmean, metabolic tumor volume (MTV), and total lesion glycolysis of the lymphomatous lesion were measured. Continuous PET parameters were stratified by their median values. Deauville scoring system was used to assess response to chemotherapy in the interim scan. Prognostic factors for overall survival (OS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method, log-rank test, and Cox proportional hazards model. Results At median follow-up of 52 months, 13 patients died and 13 had recurrence. On univariate analysis, higher whole-body MTV (WBMTV) and partial response on interim scan were statistically associated with OS. High-risk features, WBMTV, and partial response were statistically associated with DFS. On multivariate analysis combining baseline characteristics and interim response, interim response (hazard ratio, 3.56; P = 0.034) was statistically significant for OS. Multivariate analysis for DFS using only baseline characteristics revealed WBMTV as statistically significant (hazard ratio, 4.08; P = 0.035), but none of the parameters was statistically significant when baseline characteristics and interim response were evaluated together. Conclusions Whole-body tumor burden assessment with MTV and interim response may help to identify high-risk patients who might get benefitted from intensive therapy.

We herein present a case of carcinosarcoma gallbladder with osteosarcomatous differentiation in a middle-aged woman. This is seen on 18F-FDG PET/CT study as an intensely FDG-avid mass in the gallbladder with foci of calcification due to the presence of osteoid. This is a rare malignancy with poor prognosis.

Secondary involvement of inferior vena cava is a common presentation in aggressive solid malignancies, especially arising from kidneys, adrenals, and hepatobiliary system, mostly resulting from local infiltration. Rarely, primary tumors are seen arising from vascular tissue. The Ewing family of tumors commonly arises from bone, but there is a high propensity of these tumors to originate from nonosseous sites of mesenchymal cell origin. We would herewith demonstrate a rare presentation of Ewing sarcoma, seen originating from inferior vena cava, presenting as extensive intravascular tumor thrombosis, evaluated on FDG PET/CT imaging in a 12-year-old girl.

A 23-year-old man with metastatic osteosarcoma, with disease progression on conventional chemotherapy, was treated with regorafenib, a multikinase inhibitor. After treatment for 6 months with regorafenib, 18F-FDG PET/CT scan demonstrated FDG uptake in a necrotic space-occupying lesion involving tail of pancreas. After imaging, patient described symptoms of epigastric pain with elevated serum amylase and lipase levels, confirming diagnosis of regorafenib-induced pancreatitis, because patient had no other causative factors of pancreatitis. Physicians should be aware of rare and possibly clinically silent adverse effects of tyrosine kinase inhibitors, like acute pancreatitis, and recognize the 18F-FDG PET/CT findings to guide appropriate clinical management.

Ga prostate-specific membrane antigen (PSMA) PET/CT is used in the staging, evaluation of biochemical recurrence, and response assessment of patients with prostate cancer. In addition to the PSMA-expressing prostate cancer cells, Ga-PSMA binds to the neovasculaature of various other solid tumors and benign lesions. We report a case of a 72-year-old man with recently diagnosed adenocarcinoma of prostate, incidentally found to have pleomorphic sarcoma on the staging Ga-PSMA PET/CT.

Ventriculoperitoneal shunt malfunction is common in patients after shunt surgery. Imaging is done to reveal the underlying cause and confirm the diagnosis. Shunt infection is one of the common causes of shunt malfunction. FDG PET CT is an accepted infection imaging tool and can be used to diagnose shunt infection accurately in a patient with high clinical suspicion.

Osteosarcoma is the most common bone sarcoma in adolescents and children. Tumor thrombus arising from osteosarcoma is rare. We describe the case of a 13-year-old girl with osteosarcoma of the right femur, in whom the F-NaF PET/CT was done for initial staging to look for skeletal metastases. The scan showed abnormal increased tracer uptake in the primary tumor and the right common femoral and external iliac vein representing a tumor thrombus. Our case emphasizes the importance of extraosseous findings on F-NaF PET/CT, which may result in important management changes.

Extramedullary involvement in multiple myeloma is rare, but carries poor prognosis. We describe the FDG PET-CT findings of rare adrenal involvement in a case of multiple myeloma.

AIDS-related dementia complex is the most severe form of cognitive dysfunction in a patient infected with human immunodeficiency virus. The use of FDG PET/CT to diagnose AIDS-related dementia complex has been studied previously and shows various specific metabolic patterns from striatal hypermetabolism in early asymptomatic stage to global hypometabolism in advanced stages. We present a case of a 49-year-old patient with long-standing human immunodeficiency virus infection, where global brain hypometabolism was noted coincidentally on FDG PET/CT done for initial staging of primary pulmonary non-Hodgkin lymphoma.

We report the imaging findings in extra-articular chondrocalcinosis in a 53-year-old man with swelling and pain in right scapular area for 1 year. Plain radiography showed a right scapular area calcific mass. The clinical suspicion was of a soft tissue sarcoma. As a part of diagnostic workup, a bone scan and a PET/CT scan were done. Bone scan revealed intense MDP uptake in the right scapular area. FDG PET/CT revealed intense FDG uptake in the mass. The biopsy revealed chondrocalcinosis. This is an addition to our long list of causes of extraosseous uptake of MDP.

Radiotherapy for gynecologic malignancies puts the pelvic bones and the sacrum at risk for insufficiency fractures. Symptoms of sacral insufficiency fractures are nonspecific and can be mimicked by degenerative diseases and metastasis; the diagnosis thus is essentially based on imaging. We

Mesenteric lymphomas are commonly seen as bulky hypermetabolic nodal masses on F-FDG PET/CT. Very rarely, these are seen as mesenteric haziness due to localized hyperattenuation of fat, known as "misty mesentery", which morphological imaging-wise has other differentials as well. We report a unique imaging finding of segmental misty mesentery with hypermetabolic mesenteric nodes on FDG PET/CT in a patient who was kept on observation due to inconclusive biopsy, which on follow-up imaging progressed to extensive lymphomatous involvement. Thus, in retrospect, this imaging feature on baseline PET/CT was diagnostic for mesenteric lymphoma.

To study the role of PET-CT in evaluating sarcomatous transformation in osteochondromas.This was a retrospective analysis of a prospective data base of 12 patients from 2005 to 2007 with a clinical diagnosis of an osteocartilaginous lesion who were referred for a FDG PET-CT study to evaluate for possible malignant transformation. Imaging was performed on a GE Discovery ST PET-CT system after intravenous injection of 370 MBq (10 mCi) of F-18 FDG.Seven patients with histopathological evidence of a sarcomatous transformation to grade II chondrosarcoma showed moderate to high FDG uptake (SUV 3.3-6.9), whereas 1 patient with a dedifferentiated chondrosarcoma showed a focus of very intense uptake (SUV 11.4). Four patients with histopathological and/or clinical or follow-up diagnosis of a benign osteocartilaginous lesion showed low grade FDG uptake (SUV 0.8-1.3). FDG uptake was also noted in an asymptomatic osteochondroma which on histopathology revealed a grade II chondrosarcoma.Whole body FDG PET-CT is an important adjunct to conventional morphologic imaging in evaluating suspected malignant transformation in osteochondromas. Increased glucose metabolism can help diagnose sarcomatous transformation at the suspected sites as well as detect early malignant change at clinically unsuspected sites. Moreover, its ability to detect a focus of dedifferentiation can be useful for prognostication and to plan adjuvant treatment. A small cohort limits statistically sound conclusions to be drawn from this study, however further prospective trials based on these findings can help explore the potential application of FDG PET-CT in this clinical condition.

Fatty infiltration of the liver is not an uncommon imaging finding with modalities like ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI). However, when it manifests as a focal fatty change or areas of focal fat sparing, an appearance of a mass lesion is produced. F

Fibrodysplasia ossificans progressiva (FOP) is a genetic disorder of the skeletal system which, due to its rarity, is frequently misdiagnosed for a malignancy (Kitterman et al. Pediatrics. 2005;116:e654–e661). Consequently, these patients are subjected to multiple invasive diagnostic and therapeutic procedures which instead can aggravate the disease (Kitterman et al. Pediatrics. 2005;116:e654–e661). Recognition of the computed tomography appearance of FOP is thus vital, as these patients are likely to be referred for a positron emission tomography/computed tomography (PET/CT) to stage a misdiagnosed cancer. In this study, the PET/CT features of FOP are demonstrated in a child who was referred for staging of an erroneously diagnosed lymphoma.

Primary carcinoma of gall bladder is a highly aggressive malignancy, most often detected in late stage in majority of the affected patients. It commonly spreads to the adjacent liver parenchyma and, via lymphatics, to mesenteric nodes. Extra-abdominal metastatic sites are extremely rare, with lung being the commonest site. We report a rare occurrence of isolated asymptomatic bone marrow metastases from gall bladder cancer, in the absence of locoregional adenopathy, detected on whole-body F-FDG PET/CT at initial staging.

Von Hippel-Lindau (VHL) disease is a rare, inherited, multisystem disorder that is characterized by development of a variety of benign and malignant tumors. We report an incidental detection of clinically occult pancreatic malignancy on FDG PET/CT in a patient of VHL who underwent restaging for a previously treated endolymphatic sac tumor.

Extramedullary hematopoiesis refers to the presence of hematopoietic elements in locations other than the bone marrow medullary space. It occurs as a compensatory mechanism to impaired hematopoiesis resulting from a variety of pathological conditions. Because of the hazards of biopsy of a highly vascular hematopoietic mass, it is desirable to establish the diagnosis noninvasively. We report a case where 18F-fluoro-3'deoxy-L-thymidine PET/CT and 99mTc-SC scintigraphy were used as a noninvasive modality to diagnose extramedullary hematopoiesis.

One of the main limitations of 18F-fluoro-2-deoxy-glucose positron emission tomography/computed tomography (FDG PET/CT) is false-positive tracer uptake by physiological and inflammatory conditions. Continuing FDG accumulation occurs in tumors, but not in inflammatory lesions, and dual time-point FDG PET can be useful for differentiating benign from malignant conditions. Experience is rather limited, and its application in the assessment of tumors inside peritoneal cavity has been rarely reported. We present 2 cases where dual time-point FDG PET imaging proved essential in differentiating intense physiological tracer uptake from peritoneal deposits in patients with intestinal obstruction.

Secondary sarcomas arising on the background of a bone infarct are extremely uncommon. Based on the knowledge of classic imaging patterns, however, lesions like bone infarcts can be recognized during positron emission tomography/computed tomography studies, which are now being performed increasingly in cancer patients. We demonstrate the detection of this rare entity on positron emission tomography/computed tomography and its correlation on magnetic resonance imaging in a 56-year-old man with asymptomatic multifocal osteonecrosis secondary to steroid treatment for polymyositis.

Positron emission tomography (PET) using flourodeoxyglucose (FDG) is routinely used for initial staging and restaging of colorectal cancers. However FDG PET studies can suffer from false-positive tracer uptake due to a variety of physiological and inflammatory conditions arising in the abdo

A 62-year-old woman who had surgery for carcinoma of the left breast (infiltrating duct cell carcinoma grade III) and was postchemotherapy and local radiotherapy presented after 10 years with severe pain in the left shoulder and left arm. Routine follow-up investigations in these 10 years h

The standard care for muscle-invasive carcinomas of the urinary bladder is neoadjuvant chemotherapy followed by radical cystectomy and a urinary diversion procedure. Recurrence of urothelial cancer in an ileal conduit is known, but is exceedingly rare, with only a few cases reported thus fa