Somatostatin Receptor Scintigraphy Research Articles

Diagnostic Dilemma of Elevated FGF23 in a Patient With Osteomalacia: A Case Report

Introduction: Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome due to FGF23 hypersecretion. It is mostly seen with benign mesenchymal tumors. Establishing the diagnosis could be challenging due to occult nature of the disease. Case: A 54-year-old female presented with right thigh and upper back pain. On presentation, she had hypophosphatemia (1.8 mq/dl), low 25-hydroxyvitamin D (23 ng/ml), normal ionized calcium and normal iPTH (53 pg/mL). CT scan showed healing right 10th rib fracture and right proximal femoral fracture. DEXA scan was remarkable for osteoporosis. 99m-Technetium nuclear bone scan displayed hyperactivity on bilateral femurs and multiple ribs concerning for stress fractures. Patient was thought to have osteomalacia from vitamin D insufficiency and started on ergocalciferol. Two months later, patient was diagnosed with invasive ductal carcinoma. She had unilateral mastectomy and adjuvant chemotherapy. Surveillance studies were negative for recurrence. Patient lost to follow up for 2 years until she returned with right hip and upper back pain. Her labs showed hypophosphatemia (1.2 mg/dL), normocalcemia, elevated iPTH (131 pg/mL), low 25-hydroxyvitamin D (26 ng/ml), low normal 1,25-dihydroxyvitamin D (25 pg/ml, normal: 18 -72) and elevated FGF23 (285 RU/ml, normal level <180). 24-hour urine studies showed phosphate of 330 mg and fractional phosphate excretion (FEPO4) of 12%. Nuclear bone scan reported subacute fractures in left 11th and right 6th ribs and right proximal femur. TIO was entertained as the unifying diagnosis. She was started on calcium, phosphate, ergocalciferol and calcitriol. Localizing studies with a PET scan showed FDG hyperactivity in the right vocal cord. Subsequent MRI showed asymmetric fat tissue between esophagus and left common carotid artery concerning for lipoma. She lost to follow up again during COVID-19 pandemic. Discussion: We present a case of elevated FGF23 with renal phosphate wasting concerning for TIO. This case represents the diagnostic dilemma of elevated FGF23 as well as difficulty in discerning the source in TIO. Although exact tumor source remained unclear in our patient, adipose tissue in the thoracic inlet was a potential culprit. Elevated FGF23 leads to urinary phosphate wasting and inhibition of 1α- hydroxylase. Daily urine phosphate excretion > 100 mg or FEPO4 > 5 % strongly suggest renal phosphate wasting. TIO and iron-induced hypophosphatemia are two most common acquired causes of high FGF23. TIO is mostly caused by benign soft tissue and bone tumors. It can take years to establish the diagnosis due to small size and obscure location of the tumors. Advanced investigation with FDG-PET, 68Ga-DOTATATE scan, octreotide scan and venous sampling of FGF23 can aid in diagnosis. Tumor resection is usually curative. Burosumab (anti-FGF23 monoclonal antibody) can be considered when the tumor is not amenable to resect.

Presyncope in a Woman With Incidental Bladder Mass: A Case of De Novo SDHB Mutation Bladder Paraganglioma

Background: Paragangliomas (PGLs) are catecholamine secreting neuroendocrine tumors originating from extra-adrenal neural crest cells. Urinary bladder paragangliomas (UBPGLs) are extremely rare, accounting for only 0.06% of all bladder tumors. Sporadic UBPGLs associated with Succinate Dehydrogenase B (SDHB) mutation have a higher malignant potential versus patients with a positive family history due to a lack of screening. We present a case of sporadic UBPGL detected early due to follow-up of an incidental bladder mass. Clinical Case: A 31 year-old female presented to the ER with presyncope and lower abdominal pain while running. On arrival she was mildly hypertensive with BP 140/88 mmHg, HR was 98 beats/min, other vital signs were stable. Denied headaches, diaphoresis, or weight loss. No known personal or family history of any endocrine disorders or cancer. CT abdomen pelvis performed for the evaluation of her abdominal pain revealed a large fibroid along with an unexpected finding of a 3 cm enhancing lesion in the right bladder wall, suggestive of a PGL. 24 hr urine total catecholamines and plasma total metanephrines were elevated at 284 mcg (normal range 26-121 mcg/24h), and 386 pg/mL (normal <205 pg/ml) respectively, confirming the diagnosis of UBPGL. Chromogranin A was within the normal range. Metastasis was ruled out with metaiodobenzylguanidine (MIBG) whole-body scan and octreotide scan which showed isolated uptake in the bladder. Pan CT scan was negative for other SBHB mutation associated tumors such as RCC (14% incidence), GIST, and thyroid carcinoma. Genetic testing with PGLNest revealed a heterozygous SDHB mutation (5’-3’ UTR_5’-3’ UTR deletion). Her parents were found to be negative for the mutation. During follow up she developed episodic palpitations. She was treated with alpha followed by beta blocker and underwent successful resection of the tumor with partial cystectomy, and of the fibroid with myomectomy on the same day (TAH was avoided to minimize manipulation of the uterus hence decreasing the risk of intra-abdominal HTN crisis). She has been tumor-free in the three years of follow up post-surgery with imaging and biochemical surveillance. Conclusion: This case illustrates the importance of following up on incidental radiographic findings and adds to the limited literature on sporadic UBPGLs, an uncommon, yet potentially life-threatening tumor. The diagnosis of these tumors is especially challenging when patients present with non-specific symptoms. Fortunately, in our case, the imaging study clued us into the possibility of a PGL. SDHB mutation associated PGLs, in particular, are notorious for their late presentation with metastasis and associated tumors. Hence, timely detection with close follow-up of these patients will likely have an impact on their mortality.

Late Onset of Abiraterone Severe Hypokalemia Due to Unsuspected ACTH-Secreting NEC

Clinical Case: 68-year-old male, Active smoker (30-40 packs/year), and moderate alcohol drinker. An increase in urinary frequency, nocturia, and a PSA of 116 µg/L led to the diagnosis of disseminated castration-sensitive prostate cancer (CSPC), advanced Gleason score (3 + 4 pT2), with bone and retroperitoneal metastases (CT). By 02/2018, he started androgen deprivation therapy (ADT) with Abiraterone (AB) 1000 mg, prednisone, and LHRH agonist. 15 months later, PSA levels decreased to 0.75 ng/ml without side effects and normal K+(3.7 mEq/L), when a CT scan revealed both liver and bone metastasis. During the progression study, two months later, the patient was admitted to the hospital for severe hypoK+ (1.7 mEq / L), normal renal function and metabolic alkalosis. Although abiraterone was discontinued, up to 460 mEq iv per day of K+ and spironolactone were required to maintain serum K+ above 2.5. 3 days later, the hormonal study revealed TSH 1.13 mU /L, ACTH 162 pmol/L, cortisol 258 nmol/L, aldosterone 105 pmol/L, renin (protein) 0.7 µU/mL and deoxycorticosterone 507 pmol/L. 11 days later, plasma cortisol was 967 nmol/L, ACTH 132pmol/L, and cortisoluria 1456 nmol/d. The suppression test with 1 mg of DXM for cortisol was 1162,5 nmol/L. DHEAS was < 407 nmol/L. Liver biopsy showed a small cell neuroendocrine carcinoma (NEC), chromogranin (+), synaptophysin (+), CD56 (+), TTF-1 (+), PSA (-), Ki-67 90% and the granular cytoplasmic ACTH (+). The octreotide scan (+) revealed pathological uptake in L4, multiple uptakes in the liver, and in the axial skeleton. Treatment with Carboplatin plus Paclitaxel for NEC was started, completing 3 weekly doses with good tolerance and clinical benefit, but with the persistence of severe hypoK+ (2.5 mEq/L). Treatment with lanreotide 120 mg every 4 weeks was added, following a feeling of clinical improvement, the disappearance of edema, asthenia, and normalization of plasma K+ (3,4mEq/L). The patient died two months later from respiratory sepsis. Discussion: Several clinical trials have demonstrated that the combination of AB plus ADT prolongs overall survival in DCSPC. The CYP17 inhibition by AB increases ACTH leading to early secondary mineralocorticoid excess with hypokalemia and hypertension while the cortisol levels remain normal or low. Cortisol serum levels increased after AB was discontinued, whereas aldosterone serum levels remained low due to K+ regulatory feedback. The hormonal profile and the pathological and radiological studies revealed an ACTH-producing small cell NEC. In this patient, the previous treatment with BA has masked the clinical and hormonal profile of an ectopic Cushing syndrome. Therefore, Cyp17 inhibitors can mask adrenal or extra-adrenal processes characterized by alterations in steroid metabolism. This case has suggested a more thorough assessment of the adrenal hormonal profile including ACTH during BA treatment.

The Diagnosis and Management of a Rare ACTH-Producing Neuroendocrine Tumor Causing Cushing’s Syndrome

A 57-year-old woman presented with a three-month history of worsening lethargy, weight gain, central adiposity, proximal muscle weakness, and hypokalemic hypertension. Initial investigations were consistent with ACTH-dependent Cushing’s Syndrome. 24-hour urine cortisol: 711nmol/day (normal<275), cortisol after 1 mg dexamethasone suppression test 960nmol/L (normal<50)), 2-day dexamethasone suppression cortisol: 575 and ACTH: 19 pmol/L. MRI sella was normal. She required several hospital admissions for worsening proximal muscle weakness and falls. She was started on ketoconazole and spironolactone. Basal insulin was started for dysglycemia. Petrosal vein sampling indicated ectopic ACTH production. CT scan of chest/abdomen/pelvis showed no intrathoracic or intra-abdominal abnormality. Thyroid ultrasound and whole-body octreotide scan showed no abnormalities. A Gallium 68-dotatate PET scan showed focal tracer uptake in the pancreatic tail suspicious for a well-differentiated neuroendocrine tumor (NET). MRI pancreas showed a slightly truncated pancreatic tail with no discrete lesion. We proceeded with Endoscopic Ultrasound (EUS) which revealed an irregular hypoechoic mass in the pancreatic tail. EUS–guided fine-needle biopsy (EUS-FNB) using a 22G SharkCore needle, revealed a neuroendocrine neoplasm staining positively for ACTH. She underwent distal pancreatectomy with pathology showing a 1.4cm well-differentiated NET, staining positive for ACTH with a Ki67 index of 10%. Postoperatively, her ketoconazole, spironolactone, and insulin were discontinued. Her dysglycemia, hypertension and other clinical symptoms gradually improved. Immediately post-operatively, her AM cortisol was 403 and her 24-hour urine cortisol was elevated 959nmol/day. Repeat AM cortisol and 24-hour urine cortisol one-month post-surgery were 392 nmol/L and 72 nmol/day respectively, confirming biochemical remission. Discussion: ACTH-producing pancreatic NETs are rare, accounting for less than 15% of reported cases of EAS. They are often aggressive, with 78.7% of reported cases having distant metastasis at diagnosis (1). They are associated with significant morbidity and mortality. Diagnosis and management can be difficult and require multiple investigations and multidisciplinary team involvement. In our case, we utilized endoscopic ultrasound to ensure a correct preoperative localization. We discuss the systematic approach for diagnosis and the management of an ACTH-producing pancreatic NET.

Coexistent CYP24A1 and PHEX Gene Mutations With Hypervitaminosis D Plus Hypercalcemia Treated With Fluconazole

Background: CYP24A1 and PHEX gene mutations are rare and can cause hypercalcemia, hypervitaminosis D and elevated FGF23 levels. Fluconazole, an antifungal medication, has shown therapeutic benefit in achieving normocalcemia plus normalisation of vitamin D levels in this case report. Clinical Case: A 42 year old man was referred to the endocrine clinic with a history of severe nephrocalcinosis and recurrent nephrolithiasis requiring surgical intervention and gradual decline in kidney function over 20 years. Biochemical investigations revealed hypercalcaemia with adjusted calcium levels of 2.83 mmol/L (R 2.2–2.6 nmol/L) and suppressed PTH 1.1 pmol/L(R 1.6–6.9 pmol/L). Twenty-four hour urine calcium/creatinine clearance ratio was above 0.0578 mmol/mmol indicating hypercalciuria. Vitamin D metabolites 25 OH Vitamin D was elevated at 201 nmol/L, (R 50–120 nmol/L) along with intermittently elevated 1,25 OH Vitamin D 147 pmol/L(R 55–139 pml/L). 24,25 Vitamin D was low at 2.0 nmol/L producing a 25:24,25 dihydroxyvitamin D ratio of 80 (n<25). This biochemical data was highly suggestive of a loss of function mutation in the CYP24A1 gene that codes for the enzyme 24-hydroxylase, which is responsible for conversion of 1,25 vitamin D to 24,25 vitamin D. A pathogenic variant (heterozygous c.756G>A) was confirmed on genetic testing.Plasma FGF23 (immutopics) was raised (with a peak of 596 RU/mL, n<100 RU/mL) but a full body octreotide scan did not reveal malignancy or other paraneoplastic syndromes such as oncogenic osteomalacia. A pathogenic variant in his PHEX gene (homozygous c.1874A>T) was also identified that has been associated with increased levels of FGF23 plus hypophosphataemia. Fluconazole at 50 mg once daily was initiated. Azoles inhibit cytochrome P450 enzymes and have been used in sarcoidosis to block vitamin D-synthesizing enzymes such as 25-hydroxylases and 1-α-hydroxylase that are P450 dependent. Few cases of CYP24A1 gene defects have been treated with fluconazole, which has a favourable side effect profile and yields good results. Adjusted calcium reduced to 2.62 nmol/L, 25 OH Vitamin D normalised to 111 nmol/L and 24:24,25 dihydroxyvitamin D ratio is now 17. Patient’s liver functions and full blood count has been monitored regularly during the course of treatment and the drug was well tolerated. Conclusion: Genetic causes of hypercalcemia can be left undiagnosed for long periods and there is a lack of proven or definitive therapeutic agents for correction of elevated calcium. Here fluconazole has been shown to reduce the hypercalcaemic burden and effectively lowered the Vitamin D levels in this case of a CYP24A1 mutation. This study augments fluconazole use in these cases but further studies are needed to elucidate the long term safe usage.

Debulking surgery for functional pleural dissemination of parathyroid carcinoma-case report

BackgroundA rare cause of primary hyperparathyroidism (PHPT) is a parathyroid carcinoma. Hypercalcemia with an elevated parathyroid hormone (PTH) level seen in recurrent and metastasis disease cases is often refractory to medical therapy, thus surgical resection is recommended when possible. We performed debulking surgery for pleural dissemination of parathyroid cancer for improvement of symptoms in a patient with hypercalcemia.Case presentationA 30-year-old male with hypercalcemia was diagnosed with parathyroid cancer. Following surgery, intact PTH level elevation and hypercalcemia progression due to recurrent disease were noted. An active status of functional left pleural dissemination was revealed in 99mTc-methoxyisobutylisonitrile and somatostatin receptor scintigraphy results, but not in the area of pulmonary metastasis, and debulking surgery was performed. Thereafter, the PTH level was decreased temporarily and activities of daily living improved.ConclusionAggressive resection of metastatic disease in patients with a parathyroid carcinoma is taken into consideration to control hypercalcemia.

Combined primary hepatic neuroendocrine carcinoma and hepatocellular carcinoma: case report and literature review

BackgroundHepatocellular carcinoma (HCC) can grow in a mosaic pattern, often combined with various non-hepatocellular cells. However, HCC combined with a neuroendocrine carcinoma (NEC) component is rarely reported, and its clinical features, origin, diagnosis, and behavior have not been established. In the literature, mixed HCC–NEC tumors are categorized as either collision type or combined type, depending on their microscopic features. Here, we report a patient with a combined-type HCC–NEC tumor.Case presentationAn asymptomatic 84-year-old woman was found to have a solid mass in the right lobe of the liver. Laboratory and radiologic examinations showed typical findings of HCC, including arterial-phase enhancement, and portal- and delay-phase washout. She was treated by partial laparoscopic hepatectomy of segment 5. Pathological examination showed that the tumor was predominantly HCC, partly admixed with an NEC component. A transitional zone between the HCC and NEC tissues was also observed. The tumor was finally diagnosed as a combined-type primary mixed NEC–HCC tumor. After the preoperative diagnosis, the patient underwent somatostatin receptor scintigraphy to detect the primary NEC lesion, but no accumulation was found in any other part of her body. She has been free of recurrence for 9 months since the surgery.ConclusionMixed HCC–NEC tumors are extremely rare, and correct diagnosis requires multidisciplinary collaboration. The accumulation of further cases is needed to help understand the exact pathology, diagnosis, and treatment of this disease.

A rare case of ectopic ACTH syndrome caused by primary renal neuroendocrine tumor.

SummaryEctopic adrenocorticotropic hormone (ACTH) secretion is responsible for 5–15% of Cushing’s syndrome (CS). Neuroendocrine tumor (NET) is a common cause of ectopic ACTH syndrome (EAS). However, primary renal NET is exceedingly rare. Fewer than 100 cases have been reported and only a few cases presented with CS. Because of its rarity and lack of long-term follow-up data, clinical manifestations, biological behavior and prognosis are not well understood. Here, we report the case of a 51-year-old man who presented with clinical and laboratory findings compatible with EAS. CT scan revealed a lesion of uncertain nature at the lower pole of the left kidney. Octreotide scan found a filling defect at the lower pole of left kidney. It was difficult to determine if this finding was the true etiology or an incidental finding. Unfortunately, the patient’s clinical status rapidly deteriorated with limited medical treatment. The patient underwent left nephrectomy and left adrenalectomy. Histopathological examination confirmed NET with oncocytic features. Immunohistochemistry staining was positive for ACTH. The patient’s condition gradually improved. Additionally, glucocorticoid replacement was required only 6 months during a gradual recovery of hypothalamic pituitary adrenal axis achieved approximately three years after tumor removal. Although extremely rare, primary renal NET should be considered as a cause of EAS particularly in a patient with rapid clinical deterioration. Thorough investigation, early diagnosis and careful management are crucial to reduce morbidity and mortality.Learning pointsPrimary renal NET is an extremely rare cause of ectopic ACTH syndrome.Ectopic ACTH syndrome has a rapid onset with severe clinical manifestations. In this case, the patient’s condition deteriorated rapidly, resulting from severe hypercortisolism. Resection of the tumor is the most effective treatment.Localization of ectopic ACTH-secreting tumors is very challenging. Multimodality imaging including CT, MRI, octreotide scan, and positron emission tomography plays a crucial role in identifying the tumors. However, each imaging modality has limitations.

Somatostatin receptors: an alternative treatment target for advanced Merkel cell carcinoma.

Merkel cell carcinoma (MCC) is a rare but aggressive skin cancer with a high risk of returning and spreading. It affects about 2500 new patients every year in the USA. Current effective treatments for advanced MCC include immunotherapy and chemotherapy. Immunotherapy helps a patient's immune system fight against cancer, but only half of MCC patients have long-term benefit. Chemotherapy works initially, but the cancer starts growing again after an average of 90 days. Moreover, chemotherapy can cause severe side-effects. Therefore, we need newer treatments for advanced MCC. Somatostatin analogues (SSAs), a therapy targeted to cancer cells that have somatostatin receptors (SSTRs) on their surface, works well in some cancers. In our study, we tested whether MCC cells have SSTRs on their surface, which would allow SSAs to bind, and whether SSAs fight well against MCC tumours. We first needed to know how often MCC tumours have SSTRs within the tumour cells because SSAs need to bind to SSTRs to work. We checked this by using somatostatin receptor scintigraphy (a special type of radiologic scan) in 40 patients and by pathologic staining (colouring the tumour cells on a biopsy with a dye for better visibility). Thirty-three of 39 (85%) patients had some level of SSTRs in their tumours. We then treated 19 of these patients with SSA, and about 40% of patients benefitted without bad side-effects. Our data supports that targeting SSTRs should be tested further in advanced MCC. Linked Article:Akaike et al. Br J Dermatol 2021; 184:319-327.

Somatostatin Receptor Scintigraphy in a Patient with Myocarditis

We report a case of myocarditis imaged with technetium-99m octreotide cardiac single-photon emission computed tomography which showed diffuse uptake in the myocardium, indicating inflammatory reaction to myocardial damage. Somatostatin receptor scintigraphy of the heart could be considered in patients with suspected cardiac inflammation. This could facilitate early diagnosis and guide appropriate treatment.

Recurrence of a neuroendocrine tumor of adrenal origin: a case report with more than a decade follow-up

BackgroundNeuroendocrine tumor (NET) with adrenocorticotropic hormone (ACTH) secretion are very rare. To our knowledge, no follow-up study is published for ACTH-secreting NET, regardless of the primary site, to show second occurrence of tumor after a long follow-up, following resection of primary tumor.Case presentationHere, we describe a 49-year-old-man with cushingoid feature, drowsiness and quadriparesis came to emergency department at December 2005. Laboratory tests revealed hyperglycemia, metabolic alkalosis, severe hypokalemia, and chemical evidence of an ACTH-dependent hypercortisolism as morning serum cortisol of 57 μg /dL without suppression after 8 mg dexamethasone suppression test, serum ACTH level of 256 pg/mL, and urine free cortisol of > 1000 μg /24 h. Imaging showed only bilateral adrenal hyperplasia, without evidence of pituitary adenoma or ectopic ACTH producing tumors. Importantly, other diagnostic tests for differentiating Cushing disease (CD) from ectopic ACTH producing tumor, such as inferior petrosal sinus sampling (IPSS), corticotropin releasing hormone (CRH) stimulation test, octreotide scan or fluorodeoxyglucose (FDG)-positron emission tomography (PET) scan were not available in our country at that time. Therefore, bilateral adrenalectomy was performed that led to clinical and biochemical remission of hypercortisolism and decreased ACTH level to < 50 pg/mL, findings suggestive of a primary focus of NET in adrenal glands. After 11 years uncomplicated follow up, the ACTH level elevated up to 341 pg/mL and re-evaluation showed a 2 cm nodule in the middle lobe of the right lung. Surgical excision of the pulmonary nodule yielded a carcinoid tumor with positive immunostaining for ACTH; leading to decrease in serum ACTH level to 98 pg/mL. Subsequently after 7 months, serum ACHT levels rose again. More investigation showed multiple lung nodules with metastatic bone lesions accompanied by high serum chromogranin level (2062 ng/mL), and the patient managed as a metastatic NET, with bisphosphonate and somatostatin receptor analogues.ConclusionThis case of surgically-treated NET showing a secondary focus of carcinoid tumor after one decade of disease-free follow-up emphasizes on the importance of long-term follow-up of ACTH-secreting adrenal NET.

Does Octreoscan add value in the differential diagnosis of parapharyngeal space lesions?

ObjectiveWe sought to evaluate the added value of complementary functional imaging in the differential diagnosis of parapharyngeal space lesions, as well as the benefit of performing a structured evaluation of diagnostic cross-sectional examinations.Materials and MethodsThis was a retrospective study of 16 patients with parapharyngeal space lesions who were referred to our facility following a cross-sectional imaging study listing head and neck paraganglioma as a possible diagnosis. Each patient underwent somatostatin receptor scintigraphy with111In-pentetreotide (Octreoscan) prior to surgical resection of the lesion. In addition, the initial computed tomography (CT) or magnetic resonance imaging (MRI) scans were reviewed by two radiologists specializing in head and neck imaging, working independently, according to predefined diagnostic criteria.ResultsIncreased somatostatin receptor expression was observed in 14 of the 16 lesions evaluated. Histopathology of the surgical specimens showed that 11 of those 14 lesions were paragangliomas. Upon review, none of the three lesions for which there was a false-positive scintigraphy result (one intravascular meningioma and two schwannomas) were found to meet enough of the conventional imaging criteria for a diagnosis of paraganglioma.ConclusionStructured analysis of imaging data increases the accuracy of the diagnosis of indeterminate parapharyngeal space lesions. Because of its high sensitivity, functional evaluation by somatostatin receptor scintigraphy should be considered a useful complementary tool for the detection of head and neck paraganglioma, provided that its limited specificity is taken into account.

Carcinoid Syndrome in a Patient with Duodenal Carcinoid Tumor

Duodenal carcinoid tumors accounts for 5% of all Gastrointestinal Neuroendocrine Tumors (GI-NETs). Only 4% of all duodenal carcinoid tumors present with a full-blown carcinoid syndrome. We report a case of duodenal carcinoid tumor presenting as carcinoid syndrome in a 58 year old man, who presented with upper abdominal discomfort, diarrhoea, hot flushes and occasional wheezing. Histopathology following endoscopic resection of the tumor and 24 hour urinary 5-Hydroxyindolacetic acid (5-HIAA) confirmed the diagnosis. Duodenal carcinoid tumors are one of the rarest tumors of gastrointestinal tract and their association with a typical carcinoid syndrome is not that common. A high level of suspicion is required for an early diagnosis. With proper resection (endoscopic or surgical) of a localized tumor, recurrence and progression of the disease can be halted. Symptoms of carcinoid syndrome should be controlled by antidiarrheal agents, inhaled β-adrenergic agonist bronchodilators and somatostatin analogs (octreotide, lanreotide). Patients should be advised to avoid stress and conditions or substances that precipitate these symptoms. Dietary supplementation with nicotinamide can help in this regard. Patients with hepatic metastases are treated with synthetic analogues of somatostatin (octreotide, lanreotide). Systemic chemotherapy is not recommended in metastatic disease by the current guidelines. Patients should be followed up by monitoring serum chromogranin and urinary 5-HIAA. EUS, CT, MRI & somatostatin receptor scintigraphy can also be used for following up the patients.

A Case of Lateral Lymph Node Metastasis from a Rectal Neuroendocrine Tumor Detected by Somatostatin Receptor Scintigraphy

A Case of Lateral Lymph Node Metastasis from a Rectal Neuroendocrine Tumor Detected by Somatostatin Receptor Scintigraphy

Somatostatin Receptor Scintigraphy: Blazing in Indium and Quenching in Gallium.

In contemplating peer-reviewed information and the business of science divulgation, in which we all are immersed, one may wonder what legacy a very quoted article will hand down to posterity and what core of knowledge will stand the tests of time, of fashion, and of planned obsolescence of

Clinical Challenges in Diagnosis, Tumor Localization and Treatment of Tumor-Induced Osteomalacia: Outcome of a Retrospective Surveillance.

Tumor-induced osteomalacia (TIO) is an acquired fibroblast growth factor 23 (FGF23)-related hypophosphatemic osteomalacia caused by phosphaturic mesenchymal tumors (PMTs) developed in the bone or soft tissue. Diagnostic delay should be addressed, and ideal techniques to localize PMTs and efficient treatment options should be explored to improve the outcomes of this rare disease. To clarify the detailed clinical course and outcomes of TIO patients, retrospective questionnaire surveys were conducted among physicians from the Japanese Society for Bone and Mineral Research (JSBMR) and the Japan Endocrine Society (JES). The primary survey collected the number of TIO patients between January 2007 and December 2018. The secondary survey aimed to obtain the detailed characteristics, laboratory data, and outcomes. Eighty-eight patients (52 males, mean: 52 years old) were included, and 24 patients were clinically diagnosed with TIO without localized PMTs. The median duration from the onset to detection of high FGF23 levels was 3.4 years, with 77 patients being initially misdiagnosed. Among the methods used to detect small, localized PMTs (≤10 mm), fluorine-18-fluorodeoxyglucose-positron emission tomography/computed tomography and somatostatin receptor scintigraphy were less sensitive than somatostatin receptor positron emission tomography/computed tomography (SRPET/CT). Systemic venous sampling (SVS) of FGF23 was performed in 53 patients; among them, SVS was considered useful for detecting localized PMTs in 45 patients with diverse tumor sizes. Finally, 45 patients achieved biochemical remission by surgery, 39 patients continued pharmaceutical treatment, including burosumab (11 patients), and four patients died. These results encouraged us to further increase the awareness of TIO and to improve the accessibility of SRPET/CT and SVS. Further evidence about the efficacy of new pharmaceutical treatments is awaited. © 2022 American Society for Bone and Mineral Research (ASBMR).

Small Cystic Pancreatic Neuroendocrine Neoplasm with Huge Liver and Bone Metastases

Pancreatic neuroendocrine neoplasms occasionally have a cystic component. We herein report a case of multiple hepatic tumors, including a huge one and a 24-mm sized pancreatic cystic lesion. The hepatic tumor showed an enhancement pattern consistent with hepatic adenoma. The pancreatic cystic lesion revealed a thickened outside border and a solid inside component, which was enhanced following a contrast study, suggesting cystic pancreatic neuroendocrine neoplasm. Surgical resection was performed. After the surgery, somatostatin receptor scintigraphy detected an occult lumbar spine metastasis. Huge multiple liver and bone metastases of the neuroendocrine neoplasm G2 component were seen, with a G1 small primary lesion.

Clinical relevance of 18F-FDG PET/CT in the postoperative follow-up of patients with history of medullary thyroid cancer.

BackgroundThe aim of the study was evaluation of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography with computed tomography (PET/CT) in the detection of active disease in the patients with suspected recurrence of the medullary thyroid carcinoma (MTC).Patients and methods18F-FDG PET/CT investigation was performed in 67 patients, investigated from 2010 to 2019. _ Follow up was performed from 6 to 116 months after surgery (median 16.5 months, x± SD = 29±28.9 months). Twenty five of 67 patients underwent 99mTc-dimercaptosuccinic acid (99mTc-DMSA) scintigraphy, 11 underwent somatostatin receptor scintigraphy (SRS) with 99mTc-HYNIC TOC while 11 123I-metaiodobenzylguanidine (MIBG) scintigraphy.ResultsFrom 67 patients, 35 (52.2%) had true positive 18F-FDG PET/CT findings (TP). Average maximal standardized uptake value (SUVmax) for all TP lesions was 5.01+3.6. In 25 (37.3%) patients findings were true negative (TN). Four (6%) patients had false positive (FP) findings while three (4.5%) were false negative (FN). Thus, sensitivity of the 18F-FDG PET/ CT was 92.11%, specificity 86.21%, positive predictive value 89.74%, negative predictive value 89.29% and accuracy 89.55%. In 27 patients (40%) 18F-FDG PET/CT finding influenced further management of the patient.Conclusions18F-FDG PET/CT has high accuracy in the detection of metastases/recurrences of MTC in patients after thyroidectomy as well as in evaluation and the appropriate choice of the therapy.

Primary hepatic gastrinoma being diagnosed preoperatively: a case report and literature review

BackgroundA majority of gastrinomas causing Zollinger–Ellison syndrome are located in the duodenum or pancreas. Primary hepatic gastrinomas are rare and difficult to diagnose. We report a rare case of primary hepatic gastrinoma, which could be diagnosed preoperatively.Case presentationA 29-year-old man with a 55-mm tumor in segments 5 and 6 (S 5/6) of the liver was admitted to our hospital. After thorough investigations, he was treated for a suspected inflammatory pseudotumor and advised to undergo routine follow-up. Two years later, he revisited our hospital with a complaint of abdominal pain, vomiting, and diarrhea. Upper gastrointestinal endoscopy revealed multiple duodenal ulcers. His serum gastrin level was 2350 pg/mL (normal: 37–172 pg/mL), suggesting Zollinger–Ellison syndrome. Abdominal computed tomography showed a 78-mm hypervascular tumor with cystic degeneration in the S 5/6 region of the liver, with a potential to increase over time. The tumor showed hypointensity on T2-weighted and hyperintensity on diffusion-weighted abdominal contrast-enhanced magnetic resonance imaging. Somatostatin receptor scintigraphy (SRS) only detected a hepatic tumor. No tumors in the gastrinoma triangle were detected by endoscopic ultrasonography. Hence, selective arterial calcium injection (SACI) test was performed to determine the location of the gastrinoma. The serum gastrin concentration increased from 4620 pg/mL to 23,600 pg/mL at 20 s after calcium gluconate injection into the proper hepatic artery. Conversely, no effect on serum gastrin level was observed after the injection into any other arteries. Extended right hepatic lobectomy and cholecystectomy were performed after percutaneous transhepatic portal vein embolization. A histopathological examination of the liver tumor revealed a gastrinoma. The patient’s serum gastrin concentration on postoperative day 1 decreased to 65 pg/mL.ConclusionWe report a surgical case of primary hepatic gastrinoma correctly diagnosed preoperatively. The patient underwent extended right hepatic lobectomy, resulting in a histological definitive diagnosis of primary hepatic gastrinoma.

Follicular Lymphoma Masquerading As a Neuroendocrine Tumor

A 73 y/o Caucasian female presented with abdominal pain for 2 years, gradually worsening in the recent past. The pain was more severe at night, especially while sleeping on her abdomen. An A/P CT scan showed a mid-abdominal mesenteric mass measuring 8 x 4 cm, which was new since prior examinations. The new mass was accompanied by prominent retro-peritoneal lymph nodes, the largest along the left paraaortic region measuring 1.9 x 1.6 cm. She reported good appetite and denied fever, chills, night sweats or unexplained weight loss. She admitted to a 6-month history of diarrhea consisting of 2-3 loose stools daily. Her clinical presentation was felt to be concerning for Carcinoid tumor. A GA-68 dotatate PET/CT showed uptake within the known mesenteric mass, most likely representing carcinoid tumor. Minimal uptake observed in retroperitoneal lymph nodes felt to represent early metastatic disease. The patient underwent laparotomy, small bowel resection and retroperitoneal lymph node resection. Pertinent laboratory studies - Chromogranin level, pre op - 625 (ref 25 - 140) Chromogranin level post op - 54 Pathology showed grade 2, follicular lymphoma. The neoplastic cells predominantly composed of small, irregular cleaved centrocytes mixed with a minor population of centroblasts (less than 15 per high-power field). Neoplastic follicles were diffusely positive for CD20, PAX5, CD10, BCL6, and BCL2. Ki67 showed 10-20% proliferation index. Cyclin D1 was negative. Flow cytometry identified monoclonal B-cell population positive for CD10, CD19 (dim), and CD20, which expressed dim monotypic lambda light chain. CD5 negative. Discussion: There is evidence that lymphoma cells express somatostatin receptors (SSTR). Octreotide scan (111In-pentetreotide - binds to SSTR2 and SSTR5) uptake has been described in lymphomas with variable degree of avidity. Gallium Dotatate scan (68Ga-Dotatate - binds selectively to SSTR2) uptake has been previously described in a patient with large cell lymphoma. Here we describe a case of follicular lymphoma presenting with symptoms suggestive of carcinoid that showed uptake on Gallium Dotatae scan. This finding therefore warrants recognition by clinicians for potential of lymphoma presenting with positive Gallium Dotatate scan. Ruuska et al* have shown that 62% of various PET positive lymphomas (DLBCL, follicular and Hodgkin's) were also 68Ga-DOTONAC PET/CT positive and there was concordance between SSTR2 positivity by IHC and 68Ga-DOTONAC PET/CT. If this finding is confirmed in further studies, perhaps this may lead to a possible therapeutic application for 177Lu-DOTA-TATE in management of some refractory lymphomas. *Tina Ruuska et al, Acta Oncologica, 2018, vol 57, no. 2. 283-289 Figure Disclosures No relevant conflicts of interest to declare.