Mild Uptake Research Articles

"Mini Brain" Appearance in Spinal Metastasis From Type A Thymoma Detected by 18F-FDG PET/CT.

A 66-year-old man presented with persistent dull pain in the lower back for over 7 months. An expansile lytic lesion in the L4 vertebral body showed a characteristic "mini brain" appearance on MRI, which is highly suggestive of plasmacytoma. 18F-FDG PET/CT scan revealed increased FDG uptake in the L4 lesion, with an additional finding of a mass in the anterior mediastinum that showed mild FDG uptake. Lumbar surgery and complete resection of the anterior mediastinum tumor confirmed spinal metastatic type A thymoma, which was classified as p-T1aN0M1b, stage IVb. The patient's condition improved postsurgery and chemotherapy, with long-term follow-up necessary due to recurrence risk.

After 30 Years of Remission, Recurrence With Renal Cell Carcinoma Metastasis Mimicking Pancreatic Neuroendocrine Tumor on 18F-FDG and 68Ga-DOTATATE PET/CT.

A 75-year-old man with a previous history of left nephrectomy for clear cell renal cell carcinoma in remission was underwent 68Ga-DOTATATE PET/CT imaging for evaluation of pancreatic body lesion. It showed a mass with intense 68Ga-DOTATATE uptake in the pancreatic corpus. During the follow-up of the patient who did not want to undergo surgery, 18F-FDG PET/CT scan was performed due to the increase in the size of the mass, and mild FDG uptake was detected in the pancreatic corpus lesion, and histopathological examination was confirmed as renal cell carcinoma metastasis.

Mildly Increased 68 Ga-Pentixafor Uptake in Hepatic Hemangioma.

68 Ga-pentixafor uptake in hemangioma is rare. We report 68 Ga-pentixafor PET/MRI findings of a hepatic hemangioma in a 54-year-old woman. The images revealed a hyperintense lesion in the right posterior liver on T2-weighted images, with mild pentixafor uptake. The lesion was consistent with typical presentations of a hemangioma on MRI and contrast-enhanced CT.

ThP8.2 - Degree of Lymphatic dysfunction in severe obesity

Abstract Aim Obesity can affect the lymphatic system through a multitude of ways with patients presenting to lymphoedema clinics. The aim of this present study is to assess the degree of lymphatic dysfunction through Lymphoscinigraphy (LSG) scans in severely obese patients. Methods All obese patients who presented with leg swelling and underwent LSG scans were included in the study. Based on NICE guidelines they were graded as class 1 (BMI of 30-34.9 kg/m2), class 2 (35-39.9 kg/m2) and class 3 (40 kg/m2 or more). Severity of their Lymphoedema were categorised as mild (uptake 5-8%), moderate (uptake 2-5%), and severe (Uptake <2%) in accordance with the worst affected leg. These two variables were then compared. Results Of the 133 patients with BMI provided, the average BMI was 37.18Kg/m2. 54.89% of patients with BMI provided were classed as Obese.19 (26.03%) of these patients were classed as class 1 obesity and of these 68% had severe Lymphoedema. 14 (19.18%) were classed as class 2 obesity and 28% had severe Lymphoedema. 40 (54.79%) were classed as class 3 obesity and 28% had severe Lymphoedema. Conclusion Majority (75%) of obese patients had lymphatic dysfunction on LSG scans. Majority (62%) had mild to moderate Lymphatic dysfunction. Only 38% of patients with severe Obesity (40 kg/m2 or more) had severe Lymphatic dysfunction. Lymphoedema in Obesity is often not constitutional lymphoedema.

Use of Laxative-Augmented Contrast Medium Increases the Accuracy in the Detection of Colorectal Neoplasms.

Colonic adenomas are considered a precursor of colorectal cancer. A 75-year-old woman had a history of post-operation left breast cancer. She received an excision when the left chest wall recurred. A later FDG PET/CT scan revealed a focal intense FDG accumulation in the sigmoid, a focal mild FDG uptake in the pericolic lymph node, and a focal increased FDG accumulation in the transverse colon. A delayed FDG PET/CT scan after the per-rectal administration of the laxative-augmented contrast medium revealed a filling defect with persistent FDG uptake in the sigmoid and transverse colon and mild FDG uptake in the pericolic lymph node. In addition, more lesions were observed in the rectum and descending colon. The pathology reports showed sigmoid adenocarcinoma with lymph node metastasis, and adenomas in the transverse colon, descending colon, and rectum.

Increase 68Ga-FAPI Uptake in Urogenital Tuberculosis.

Urogenital tuberculosis is one of common sites of extrapulmonary tuberculosis. A 60-year-old man with an elevated prostate-specific antigen level underwent multiparametric MRI, which revealed abnormal signals in the prostate. However, the 68Ga-PSMA PET/CT results were unrevealing. Subsequent 68Ga-FAPI PET/CT imaging revealed intense radioactivity uptake in the prostate and mild radioactivity uptake in the left kidney, which was eventually proven due to tuberculosis.

Multiple Bone Involvement in Low-grade Myofibroblastic Sarcoma Demonstrated on 18F-FDG PET/CT.

A 68-year-old woman with low back pain for 2 months was admitted. T2-weighted fat-saturated imaging revealed hyperintense lesions in multiple lumbar regions, suggesting the possibility of bone metastases. Multiple osteolytic and mixed osteolytic-osteoblastic lesions with significant 18F-fluorodeoxyglucose (18F-FDG) uptake, as well as multiple osteoblastic lesions with mild 18F-FDG uptake, were observed on subsequent 18F-FDG positron emission tomography/computed tomography without an identifiable primary lesion. This patient was pathologically diagnosed with low-grade myofibroblastic sarcoma (LGMS) after biopsy and surgery. Although multiple bone involvement in LGMS is extremely rare, this case suggests that it should be considered in the differential diagnosis of multiple bone metastases.

AL–AMYLOIDOSIS RELATED ADVANCED HEART FAILURE DIAGNOSED THROUGH F–18–FLUTEMETANOL PET SCAN

Abstract Background Systemic amyloidosis (SA) is a group of rare diseases in which abnormal misfolded proteins, amyloid fibrils, accumulate in tissue. The gold standard for diagnosis is tissue biopsy of the affected organ, but it is invasive and needs specific proteomic or immunohistochemistry analyses to characterize the involved protein. We report a case of a complex diagnosis of SA in an advanced heart failure (HF) patient. Methods and Results A 68–year–old woman with history of recurrent uveitis started to complain dyspnea in 2022, after Covid19. Since her symptoms worsened, in June 2023 she was diagnosed in another center with restrictive cardiomyopathy with preserved left ventricular (LV) ejection fraction. She underwent coronary angiography (unremarkable), cardiac MRI (aspecific fibrosis), and a FDG–PET scan which showed non–homogeneous LV fixation. The patient was treated with steroids for the suspicion of an immunologic–inflammatory disease, without benefit. Fourteen months after the initial presentation, she was admitted to our centre for advanced inotrope–dependent HF. She had mildly increased LV hypertrophy and severe systolic dysfunction with restrictive physiology and, notably, peri–orbital subcutaneous hemorrhages (Figure 1). Hematological screening for amyloidosis showed elevated serum free lambda light chains. Repeated cardiac MRI scan was consistent with infiltrative disease. A total–body PET scan with dual tracer was performed. The control session with F–18–FDG showed mild aspecific cardiac uptake in the basal septum and lateral wall (Figure 2), while off–label use of F–18–Flutemetanol, an Alzheimer‘s disease approved experimental tracer that binds to amyloid fibrils beta sheets with very high sensitivity and specificity, showed intense cardiac, hepatic, pulmonary and muscular uptake, with wash–out–timing diagnostic for AL–SA (Figure 3). Periumbilical fat biopsy confirmed the clinical suspicion of SA. Hematological investigations led to the diagnosis of stage I–A lambda micromolecular multiple myeloma, with systemic amyloidosis and a IIIb cardiac prognostic score. Conclusions Endomyocardial biopsy is an invasive procedure and periumbilical fat biopsy discriminates the amyloid protein type only by proteomic analysis, which is available in very few Italian centres. The off–label use of Alzheimers’ PET tracers could reduce the delay of cardiac AL–SA diagnosis, allowing early disease identification and prompting timely hematological therapy.

Clinical and Prognostic Implications of Right Ventricular Uptake on Bone Scintigraphy in Transthyretin Amyloid Cardiomyopathy.

The extent of myocardial bone tracer uptake with technetium pyrophosphate, hydroxymethylene diphosphonate, and 3,3-diphosphono-1,2-propanodicarboxylate in transthyretin amyloid cardiomyopathy (ATTR-CM) might reflect cardiac amyloid burden and be associated with outcome. Consecutive patients with ATTR-CM who underwent diagnostic bone tracer scintigraphy with acquisition of whole-body planar and cardiac single-photon emission computed tomography (SPECT) images from the National Amyloidosis Centre and 4 Italian centers were included. Cardiac uptake was defined according to the Perugini classification: 0=absent cardiac uptake; 1=mild uptake less than bone; 2=moderate uptake equal to bone; and 3=high uptake greater than bone. Extent of right ventricular (RV) uptake was defined as focal (basal segment of the RV free wall only) or diffuse (extending beyond basal segment) on the basis of SPECT imaging. The primary outcome was all-cause mortality. Among 1422 patients with ATTR-CM, RV uptake accompanying left ventricular uptake was identified by SPECT imaging in 100% of cases at diagnosis. Median follow-up in the whole cohort was 34 months (interquartile range, 21 to 50 months), and 494 patients died. By Kaplan-Meier analysis, diffuse RV uptake on SPECT imaging (n=936) was associated with higher all-cause mortality compared with focal (n=486) RV uptake (77.9% versus 22.1%; P<0.001), whereas Perugini grade was not associated with survival (P=0.27 in grade 2 versus grade 3). On multivariable analysis, after adjustment for age at diagnosis (hazard ratio [HR], 1.03 [95% CI, 1.02-1.04]; P<0.001), presence of the p.(V142I) TTR variant (HR, 1.42 [95% CI, 1.20-1.81]; P=0.004), National Amyloidosis Centre stage (each category, P<0.001), stroke volume index (HR, 0.99 [95% CI, 0.97-0.99]; P=0.043), E/e' (HR, 1.02 [95% CI, 1.007-1.03]; P=0.004), right atrial area index (HR, 1.05 [95% CI, 1.02-1.08]; P=0.001), and left ventricular global longitudinal strain (HR, 1.06 [95% CI, 1.03-1.09]; P<0.001), diffuse RV uptake on SPECT imaging (HR, 1.60 [95% CI, 1.26-2.04]; P<0.001) remained an independent predictor of all-cause mortality. The prognostic value of diffuse RV uptake was maintained across each National Amyloidosis Centre stage and in both wild-type and hereditary ATTR-CM (P<0.001 and P=0.02, respectively). Diffuse RV uptake of bone tracer on SPECT imaging is associated with poor outcomes in patients with ATTR-CM and is an independent prognostic marker at diagnosis.

P-20 Primary hyperparathyroidism associated with maltoma of the thyroid gland: imaging challenges

Abstract Introduction Primary hyperparathyroidism (PHP) and malignancies are the most common causes of hypercalcemia. Nevertheless, PHP might be observed in coexisting with malignancies. We aimed to present a patient who underwent surgery for PHP and was diagnosed with thyroid MALToma. Clinical Case A 65-year-old female presented with fatigue for one year. The patient's medical history was unremarkable. On examination, thyroid gland was non-palpable. On laboratory, serum calcium (Ca), phosphorus (P) and parathormone (PTH) levels were 11 mg/dL (R: 8.8-10.6), 2.4 mg/dL (R: 2.5-4.5) and 157 pg/mL, respectively; vitamin-D was 23.63 µg/L and increased urinary Ca (400 mg per-day). She was euthyroid, and thyroid antibody elevated. Ultrasound (US) revealed multiple hypoechoic areas and a lesion (18×14 mm) in the vicinity of inferior right thyroid gland. Parathyroid scintigraphy revealed significant increase of metabolic activity posterior to the right lobe of the thyroid. She underwent right thyroid lobectomy thyroidectomy. Pathology revealed mucosa-associated lymphoid tissue (MALT) lymphoma of the thyroid. No parathyroid lesion noted. Then she was referred to our clinic. US revealed hypoechoic areas at remaining thyroid with no extra finding. We performed tru-cut biopsy from thyroid lesion. On immunochemistry, lymphoid cells were diffusely immunoreactive for CD3, CD5, CD20 and CD43 in the ymphocytes. Ki-67 index was 40%. Hence, the diagnosis of MALT lymphoma of the thyroid gland in the background of Hashimoto's thyroiditis. PTH staining of patient's previous pathology specimen was unremarkable. Pretreatment baseline 18F-flurodeoxyglucose PET/CT (FDG) revealed increased uptake (SUVmax: 5.1) in hypodense nodular structure in the posterior left lobe of the thyroid gland (Figure 1). FDG was suggestive of stage IE. Mild 18F-FCH uptake was observed suspected as parathyroid lesion next to the inferior left lobe. 4D-CT showed similar results. All imaging methods and we examined patient via US that revealed hypoechoic lesion with polar blood supply in the left lobe inferior (parathyroid adenoma). The patient were under rituximab 375 mg/m2 per week for 4 cycles. At the end of treatment, there were no sign of residual disease. Reoperation has not been planned due to the improvement of the patient's symptoms, and lymphoma with indolent course. Conclusion 10% of PHP cases may have a concomitant malignancy, while association with lymphoma is even rarer. MALT lymphoma of the thyroid gland is a rare malignancy with an indolent course. The combination of these two rare conditions hard to orchestrate. As in our case, detection of parathyroid lesions becomes more difficult in the background of a low grade lymphoma. Indolent lymphomas have limited sensitivity with FDG. FCH could be more sensitive for discriminating parathyroid lesions and indolent lymphomas. It may be useful to confirm the localization of the PHP in such cases using multiple techniques involving FCH.Figure 1.Pre-treatment avid FCH uptake (A, B) and mild FDG uptake (C, D) related with thyroid MALToma; post-treatment complete remission shown in FDG (E, F); highly vascular paratracheal lesion at 4D-CT (G, H asterixis), the same lesion with mild FCH uptake (I-N arrows) and the same lesion with hypoechoic sonographic appearance evaluated as parathyroid adenoma (O arrow).

Abstract 15619: Prevalence of Transthyretin Cardiac Amyloidosis in Elderly Subjects From the General Population: The Catch Study

Introduction: The exact prevalence of transthyretin cardiac amyloidosis (ATTR-CA) in the general population has never been defined. Methods: We conducted a population screening in an area of Tuscany (Italy) where there is no cluster of variant ATTR. Six general practitioners proposed study participation to a total of 2,566 subjects aged ≥65 years, with 1,000 accepting. All subjects underwent first-line exams searching the following elements of suspicion of CA: high sensitivity-troponin T ≥14 ng/L, interventricular septal thickness ≥12 mm, any echocardiographic, ECG or clinical red flag. Individuals with any of these elements were referred to the search for a monoclonal protein and bone scintigraphy. Results: Step two exams (bone scintigraphy and search for a monoclonal protein) were proposed to 346 subjects, and 216 (62%) accepted. Three patients were ultimately diagnosed with ATTR-CA (a 79-year-old woman, an 85-year-old and a 74-year-old man), and the diagnosis was deemed likely in another patient (an 83-year-old woman with mild bone tracer uptake but intense uptake in the inferior wall, not willing to undergo endomyocardial biopsy). No patient had a monoclonal protein nor TTR gene mutations. All patients with ATTR-CA had left ventricular wall thickening and complained of dyspnea on moderate effort. The prevalence of ATTR-CA was 3 out of 870 (654 [Step two not proposed] + 216 [Step two performed]) = 0.34%, or 0.46% if considering also the fourth case. Conclusions: The prevalence of wild-type ATTR-CA in the elderly population is 0.34% (established diagnoses) or 0.46% (established or likely diagnoses).

SAT487 A Case of Mistaken Identity: A Rare Presentation of Ectopic Thyroid Tissue

Abstract Disclosure: N. Doshi: None. R. Azimzade: None. A. Rajpal: None. Background: Ectopic thyroid tissue (ETT) lateral to the midline is very rare, and its presence at the carotid bifurcation is exceedingly unique. Paraganglioma is the most common primary tumor at the carotid bifurcation, often called a carotid body tumor. We hereby present a case of lateral ETT with radiological features similar to paraganglioma. Case Description: A 72-year-old female with history of GERD was referred to us for evaluation of a well-circumscribed, slightly tender left neck mass. She has had the mass for approximately 15 years with previous evaluation with ultrasound in Yemen, where she was told to undergo surgery to remove it. She did not pursue surgery at that time. She moved to the U.S. one year ago and was re-evaluated for the neck mass. On examination, a firm mass was noted on the left side of the neck, followed by an ultrasound which demonstrated a 4.5 cm mass at the left carotid bifurcation and an enlarged right thyroid lobe of the same echogenicity with no tissue in the left thyroid bed. She had no clinical symptoms suggesting of hypo or hyperthyroidism. Laboratory examination showed suppressed TSH with elevated T3 suggesting thyrotoxicosis. CT neck was obtained for further characterization of the left neck mass which showed a hyper-enhancing, lobular soft tissue mass at the carotid bifurcation extending from the mandible to the level of the thyroid isthmus, concerning for carotid body paraganglioma or schwannoma. An I-123 scan demonstrated 24% (increased) uptake in the right thyroid lobe and minimal uptake in the carotid bifurcation tissue. The patient is currently being treated medically for thyrotoxicosis. Based on its ultrasonographic appearance, mild uptake on the I-123 scan, and no clinical suggestion of paraganglioma, the left neck mass is presumed to be ETT and no surgical intervention is being pursued. It is possible that the right lobe is thyrotoxic, suppressing iodine uptake in the ectopic tissue. Conclusion: This case demonstrates a unique presentation of ETT in the left carotid bifurcation with a thyrotoxic right lobe. It is difficult to distinguish the precise composition of neck masses at the carotid bifurcation, which has important implications for management. Often, an official diagnosis of thyroid tissue is made with histopathology only after the mass is surgically excised. Most ETT is benign in nature, and many times it is the only thyroid tissue available, thus surgery is not indicated. It is especially difficult to distinguish between ETT and paraganglioma on imaging itself. Somatostatin receptor scintigraphy, Ga-68/PET scanning, or iodine uptake scan can be useful to distinguish ETT from paraganglioma. Despite its rarity, lateral ETT must be included in the differential diagnosis of carotid body paraganglioma. Presentation Date: Saturday, June 17, 2023

SAT572 Concomitant Metastatic Hurthle Cell Carcinoma And Rectal Cancer, Challenges In Diagnosis And Management

Abstract Disclosure: D. Khurram: None. R. Pansare: None. S.L. Mokshagundam: None. Hurthle cell carcinomas (HCC) are aggressive tumors and account for 5% of follicular cell thyroid malignancies. Tumor size, extra-thyroid extension and distant metastases indicate poor prognosis. 20-30% of HCCs have mets at initial diagnosis, frequent sites being lungs and bones. Metastatic HCCs are exceedingly difficult to manage. Detecting two primary cancers concomitantly is uncommon and poses additional challenges in diagnosis and management. We present an interesting case of HCC with mets to the manubrium, vertebrae, lungs and concomitant rectal adenocarcinoma. A 69-year-old male had MRI spine for back pain which showed multiple lytic osseous lesions within T3 and L1 vertebrae. Further imaging revealed a large lesion in the manubrium. Manubrial mass biopsy was positive for poorly differentiated carcinoma, immunohistochemical staining for CAM5.2, cytokeratin, CD 138, CD56 and TTF-1 (weak). He underwent 6 cycles of palliative chemotherapy with carboplatin and Taxol for carcinoma of unknown origin. PET scan following chemotherapy showed a large heterogenous thyroid mass with intense FDG uptake, along with a suspicious rectal mass. Left thyroid nodule FNA reported Bethesda IV follicular neoplasm, Hurthle cell type. Rectal mass biopsy reported moderately differentiated adenocarcinoma. Histology after total thyroidectomy showed unifocal oncocytic HCC, with lymphovascular invasion but no extrathyroidal extension. Molecular markers showed low TMB, stable microsatellite status, negative PDL-1, negative NTRK fusion and positive ATM E839. He received suppressive dose levothyroxine. Radio-iodine ablation was postponed owing to prioritization of radiation therapy for rectal cancer. Thyroglobulin level increased from 53 ng/ML to 216 ng/ML. He received 149 milli Curies of I131 after Thyrogen stimulation. There was mild radioiodine uptake in the thyroid bed, but the metastatic lesions were not radioiodine avid. Follow-up scans showed multiple bilateral pulmonary nodules with worsening osseous mets. Endoscopic biopsy was consistent with HCC, TTF-1 and PAX8 positive. He was started on Lenvatinib but developed diarrhea, hence switched to Pembrolizumab. Thyroglobulin level improved on Pembrolizumab but was complicated by adrenal insufficiency. For rectal cancer, he received radiation therapy and capecitabine. Our case is interesting for several reasons. Firstly, although bone mets are commonly seen in HCC, manubrial mets, especially as the presenting feature is rare. Secondly, concomitant rectal cancer delayed the treatment of the thyroid cancer. Thirdly, there is no major consensus regarding management of HCC, especially metastatic HCC. HCCs are often not radioactive iodine avid. Combination therapy with Lenvatinib and Pembrolizumab is currently under trial for aggressive thyroid malignancy. It will be interesting to follow the clinical outcomes in this individual. Presentation: Saturday, June 17, 2023

FRI264 A Case Of Composite Pheochromocytoma And Ganglioneuroma

Abstract Disclosure: D. He: None. J. Pullman: None. S. Stefan: None. B.Y. Wong: None. Background: Pheochromocytomas are catecholamine-secreting tumors that arise from chromaffin cells in the adrenal medulla or paraganglia. Representing 1-9% of pheochromocytomas, composite pheochromocytomas are rare tumors composed of pheochromocytoma and neural tumor components such as neuroblastoma, ganglioneuroblastoma, ganglioneuroma or peripheral nerve sheath tumor1. We present a case of composite pheochromocytoma and ganglioneuroma. Clinical Case: A 69-year-old man presented with recurrent dyspnea at rest, diaphoresis and tachycardia. He was diagnosed with heart failure with reduced ejection fraction and management included metoprolol 50 mg daily. On work-up, he was incidentally found to have a 1.2 cm left upper lobe lung lesion and an indeterminate 2.4 cm right adrenal mass on CTA chest. PET/CT scan showed an intensely avid left upper lobe lung nodule and a right adrenal mass with mild FDG uptake (SUV max 3.8). MRI abdomen demonstrated a 3.1 cm right adrenal lesion with a mildly thickened enhancing rim and a central enhancing nodular component suspicious for pheochromocytoma, metastases, schwannoma or ganglioneuroma. He then had a stroke with mild residual right-sided weakness. Oncological work-up of his lung and adrenal lesions eventually directed tissue sampling to biopsy of the adrenal lesion and pathology was consistent with pheochromocytoma. Subsequent biochemical evaluation revealed elevated plasma metanephrines of 194 pg/mL (&amp;lt;= 57 pg/mL), plasma normetanephrines of 474 pg/mL (&amp;lt;= 148 pg/mL), 24-hour urine metanephrines of 389 mcg (90-315 mcg) and 24-hour urine normetanephrines of 428 mcg (122-676 mcg). Pre-operatively, he was placed on phenoxybenazmine 10 mg twice daily and metoprolol 62.5 mg every 8 hours. The patient then underwent right adrenalectomy. The tumor nodule was adherent to and dissected off the inferior vena cava. Pathology showed composite pheochromocytoma with a small component of ganglioneuroma. Conclusion: This rare case of a composite pheochromocytoma with ganglioneuroma was diagnosed through histopathology as composite pheochromocytomas are clinically and radiographically indistinguishable from pheochromocytomas1. Management of composite pheochromocytomas with ganglioneuroma is similar to the management of pheochromocytomas, and surgical resection remains the first line treatment. Combined alpha and beta-adrenergic blockade is recommended to prevent intraoperative hypertensive crisis. However, more studies are needed to further understand these rare composite pheochromocytomas.

SAT163 Title: Adult-onset Hyperinsulinemic Hypoglycemia Due To An Activating Mutation In Glucokinase

Abstract Disclosure: S. Vaid: None. R. Ghosh: None. H. Elenius: None. C. Cochran: None. R. Chang: None. N. Nilubol: None. R. Muniyappa: None. Introduction: Glucokinase (GK), the key β-cell glucose sensor, determines the threshold for glucose-stimulated insulin secretion. Activating mutations of GK are infrequent causes (prevalence of 1.2%) of congenital hyperinsulinemic hypoglycemia (HH). Adult-onset of severe hypoglycemia due to GK-HH is extremely rare. Clinical Case: A 26-year-old well-nourished female (BMI, 27 kg/m2) with a recent history of dizziness, tremulousness, fatigue, sweating, and hunger, associated with weight gain presented for further workup. Hypoglycemia was noted, and Whipple's triad was confirmed. She had no family history of endocrine disease or hypoglycemia. Supervised fasting promptly produced symptomatic hypoglycemia with hyperinsulinemia. Laboratory studies revealed a low glucose level at 44 mg/dL; a plasma insulin level at 93 μIU/mL (&amp;lt;3 μIU/ml); a C-peptide level at 8.1 ng/mL (&amp;lt;0.6 ng/mL); pro-insulin at 266 pmol/L (&amp;lt;5 pmol/L); and beta-hydroxybutyrate &amp;lt;2.7 mmol/L. IGF2/IGF-1 ratio was 3.1 (&amp;lt;10) and renal and liver function was normal. Interestingly, a mixed meal also provoked significant hypoglycemia within an hour of consumption of a meal. Urine for sulfonylurea screen was negative, and so were anti-insulin antibodies. Imaging of the pancreas with computed tomography (CT), magnetic resonance imaging (MRI), and endoscopic ultrasound revealed a 1.2x0.8cm nodule on the superior margin of the body of the pancreas. 68Ga-DOTATATE​​ PET/CT (targeting somatostatin receptors) showed mild uptake coinciding with the nodule on the CT scan. Arteriography with calcium stimulation and venous sampling (ASVS) was non-localizing. The patient subsequently underwent laparoscopic exploration with intraoperative ultrasound (IOUS) of the pancreas followed by the enucleation of the pancreatic nodule. Histopathology of the nodule revealed a normal pancreatic tissue with no evidence of a neuroendocrine tumor. Change to multiple small meals, addition of cornstarch to diet, continuous blood glucose monitoring (CGM), diazoxide (70 mg oral, three times a day), and monthly octreotide LAR (30 mg) has allowed the patient to avoid hypoglycemia. Genetic testing by analysis of the genes known to cause hypoglycemia revealed a heterozygous GCK variant [c.1367C&amp;gt;T (p.Ala456Val), which was predicted to be a pathological mutation. This mutation is known to increase affinity for glucose, which leads to exaggerated insulin secretion. Conclusion: Our study highlights that in adults with non-insulinoma pancreatogenous hypoglycemia, genetic causes of HH should be considered in the differential diagnosis. Presentation: Saturday, June 17, 2023

Bone and joint disease – Not always a rheumatological diagnosis

Abstract A 17-year-old female presented with a 7-day history of joint pains involving the bilateral knee, ankle and small joints of the hands and feet symmetrically, associated with bilateral knee joint swelling and early morning stiffness and bilateral red eyes. General examination was normal except for pallor. Musculoskeletal system examination revealed bilateral swollen and tender knee joints with restriction of movement along with tenderness in the bilateral shoulder, elbow, ankle joints and spine from T3 to T7 thoracic vertebral levels. Examination of other systems was normal. Investigations showed anaemia, elevated urea and creatinine. Skeletal survey showed multiple lytic lesions. Positron emission tomography revealed multiple punched-out lytic lesions in skull bones, scapulae, sternum, clavicles, ribs on both sides, vertebrae at multiple levels and in pelvic girdle bones. Few lesions showed mild 18fluorodeoxyglucose (18FDG) uptake, metaphyseal moth-eaten lysis in long bones with mild FDG uptake. Bone marrow biopsy and immunohistochemistry confirmed the diagnosis of acute B-cell lymphoblastic leukaemia. The terminology is according to 2016 revision of WHO classification of myeloid neoplasms and acute leukemia.

Radiation Induced Lumbar Plexopathy (RILP) in Patients of Cancer Cervix Treated by IMRT Technique: A Study of Dosimetry and Clinical Correlation

To assess the Dosimetric parameters of lumbo sacral plexus in carcinoma cervix patients treated with concurrent chemo-radiation by Intensity modulated radiotherapy (IMRT) technique & to clinically correlate these Dosimetric parameters with the lumbo sacral plexus toxicity. Total twenty-four patients were included in this study between December 2020 to December 2021. They were all treated by Intensity modulated radiotherapy (IMRT) technique. Radiotherapy dose delivered was 50Gy in 25 fractions at 2Gy/#, it was followed by 3 applications of intracavitary brachytherapy of 7Gy/ fraction each. The lumbo-sacral plexus was delineated according to guidelines given by Sun and Xi et al. No dose constraint was prescribed to the lumbo-sacral plexus prior to the treatment. Magnetic resonance imaging (MRI) of bilateral lumbo-sacral plexus test was done prior to the treatment and 12 months' post treatment. Dose received by the lumbo-sacral plexus was calculated DVH parameters was evaluated. The lumbo-sacral plexus toxicity was assessed by the 10-point questionnaire pre-treatment & post treatment and was compared. Assessment of toxicity was done by RTOG (Radiation Therapy Oncology Group) scoring criteria. Out of the 24 patients treated, 7 patients had gross nodes which were treated with a boost dose of 60 Gy. Out of these patients 9 patients (37.5%) developed signs and symptoms of radiation induced lumbar plexopathy (RILP). Among these patients, the most common symptom was weakness in the lower limbs followed by impaired leg movement and activities interfering daily activities such as walking, squatting and getting up from the chair. Other positive findings included stiffness, lower limb pain, lower back ache radiating the lateral aspect of the thigh and numbness of the lower limbs. Total prescribed dose to 95% of the planned target volume ranged from 49.2Gy - 61.9 Gy (median - 57 Gy). The mean volume of the LS plexus was 128 cc (range, 92- 143 cc). The mean of the D-max of LS plexus was 56.2 Gy (range, 43.2 Gy- 61.9 Gy). The V30 Gy was received by 84 % of LS plexus, whereas V40, V50, V60 was received by 64 %, 13 % and 4%. The most common significant findings on MRI post treatment were unilateral thickening of the nerve roots followed by hyperintensity in T2 weighted image and STIR sequencing. Mild contrast uptake and edema were present in the nerve roots. Radiation induced lumbar plexopathy (RILP) is one of the late complications after chemoradiotherapy in patients of carcinoma cervix, which is often misdiagnosed or missed on follow up. Therefore, lumbar plexus must be contoured in all pelvic malignancies which are treated by chemoradiotherapy with IMRT technique as it prevents dose dumping in that region. Further studies with longer follow up are needed.

18F-FDG PET/CT Findings in Monkeypox Infection in an HIV Patient.

A 29-year-old man diagnosed with monkeypox infection underwent an 18F-FDG PET/CT for the study of organic involvement in the context of a nonsatisfactory clinical evolution. He had a history of HIV (with undetectable viral load). FDG PET/CT showed multiple hypermetabolic lymphadenopathies and bilateral pulmonary nodules with mild 18F-FDG uptake.

Positron emission tomography assessment of metacarpal/metatarsal condylar fractures post surgical repair: Prospective study in 14 racehorses.

To assess 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) findings associated with metacarpal/metatarsal condylar fractures at the time of fracture repair and through healing. Prospective descriptive study. Fourteen Thoroughbred racehorses. 18F-NaF PET was performed within 4 days of surgical metacarpal/metatarsal condylar fracture repair, on both the injured and contralateral limb. Follow-up PET scans were offered at 3- and 5-months post fracture repair. Areas of abnormal uptake were assessed using a previously validated grading system. Eight fractures were located in the parasagittal groove (PSG) (six lateral and two medial) and six fractures were located abaxial to the PSG (non-PSG) through the palmar/plantar condyle (all lateral). All horses in the latter group had uptake in the lateral palmar condyle of the contralateral limb suggestive of stress remodeling. Three horses with PSG fractures had uptake in a similar location in the contralateral limb. Horses with lateral condylar fracture only presented minimal or mild uptake in the medial condyle, which is considered atypical in the front limbs for horses in full training. Four horses developed periarticular uptake in the postoperative period suggestive of degenerative joint disease, three of these horses had persistent uptake at the fracture site. These four horses did not return to racing successfully. The findings of this study provide evidence of pre-existing lesions and specific uptake patterns in racehorses suffering from metacarpal/metatarsal condylar fractures. PET has a possible role in the prevention, diagnosis, and postoperative monitoring of metacarpal/metatarsal condylar fractures in racehorses.

Rate of benign nodule resection in a lung cancer screening program

PurposeScreening with low dose computed tomography (CT) can reduce lung cancer related death at the expense of unavoidable false positive results. The purpose of this study is to measure the rate of surgery for benign nodules, and evaluate characteristics of those nodules. Materials and methodsIn this study, we evaluated patients in the Lung Cancer Screening (LCS) program across a large tertiary healthcare network from 5/2015 through 10/2021 who underwent surgical resection for a lung nodule. We reviewed the pathology reports and subsequent follow-up to establish whether the nodule was benign or malignant. Imaging characteristics of the nodules were evaluated by a radiology fellow, and we recorded Lung-RADS category, nodule status (baseline, stable, new, growing), FDG uptake on PET/CT, and calculated the risk from the Brock model. ResultsDuring this time period, a total of 21,366 LCS CT was performed in 9050 patients, and 260 patients underwent a following surgical resection. Review of the pathology results revealed: 220 lung cancer (85%), 2 other malignancies (1%), and 38 benign findings (15%). Pathology of the benign nodules was as follows: 12 with scarring/fibrosis, 5 with benign neoplasms, 14 with infection/inflammation, and 7 with other diagnoses. Lung-RADS category was as follows: 4 (11%) Lung-RADS 2, 2 (5%) Lung-Rad 3, 11 (29%) Lung-RADS 4A, 13 (34%) Lung-RADS 4B, and 8 (21%) Lung-RADS 4X. The size of the nodules ranged from 4 to 41 mm with a median of 13 mm. 2 (5%) were ground glass, 10 (26%) were part-solid, and 26 (68%) were solid. FDG-PET/CT was performed in 19 out of 38 cases, of which: 2 (11%) had no uptake, 10 (53%) had mild uptake, 3 (16%) had moderate uptake, and 4 (21%) had intense uptake. Risk assessment by Brock calculator revealed that 9 (24) had <5% (very low) risk; 27 (71%) had 5–65% (low-intermediate) risk, and 2 (5%) had >65% (high) risk. ConclusionSurgical resection of benign nodules is unavoidable despite application of Lung-RADS guidelines in a modern screening program, with approximately 15% of surgeries being done for benign lesions.