Anatomic and functional imaging of metastatic carcinoid tumors

Nuclear medicine imaging for bone metastases assessment: what else besides bone scintigraphy in the era of personalized medicine?

Accurate detection and reliable assessment of therapeutic responses in bone metastases are imperative for guiding treatment decisions, preserving quality of life, and ultimately enhancing overall survival. Nuclear imaging has historically played a pivotal role in this realm, offering a diverse range of radiotracers and imaging modalities. While the conventional bone scan using 99mTc marked bisphosphonates has remained widely utilized, its diagnostic performance is hindered by certain limitations. Positron emission tomography, particularly when coupled with computed tomography, provides improved spatial resolution and diagnostic performance with various pathology-specific radiotracers. This review aims to evaluate the performance of different nuclear imaging modalities in clinical practice for detecting and monitoring the therapeutic responses in bone metastases of diverse origins, addressing their limitations and implications for image interpretation.

The role of HMGA1 protein in gastroenteropancreatic neuroendocrine tumors

Neuroendocrine tumors (NETs) are neoplasms derived from neuroendocrine cells. One of their main features is to often remain asymptomatic and clinically undetectable. High Mobility Group A (HMGA) proteins belong to a family of non-histone chromatinic proteins able to modulate gene expression through the interaction with DNA and transcription factors. They are overexpressed in most of the human malignancies, playing a critical role in carcinogenesis. However, their expression levels and their role in neuroendocrine carcinogenesis has not been exhaustively evaluated until now. Therefore, in this study, we have addressed the validity of using the expression of HMGA1 as a diagnostic marker and have investigated its role in NET carcinogenesis. The expression of HMGA1 has been evaluated by qRT-PCR and immunohistochemistry, using NET tissue microarrays, in a cohort of gastroenteropancreatic (GEP)-NET samples. The expression levels of HMGA1 have been then correlated with the main clinical features of NET samples. Finally, the contribution of HMGA1 overexpression to NET development has been addressed as far as the modulation of proliferation and migration abilities of NET cells is concerned. Here, we report that HMGA1 is overexpressed in GEP-NET samples, at both mRNA and protein levels, and that the silencing of HMGA1 protein expression interferes with the ability of NET cells to proliferate and migrate through the downregulation of Cyclin E, Cyclin B1 and EZH2. These results propose the HMGA proteins as new diagnostic and prognostic markers.

Radiology of the neuroendocrine neoplasms of the gastrointestinal tract: a comprehensive review

Neuroendocrine neoplasms (NENs) are a group of neoplasms arising from the diffuse endocrine system (DES). The gastrointestinal tract (GIT) is the most common site of NEN. The WHO classification divides NEN into three broad categories viz. well-differentiated NENs, poorly differentiated NENs, and mixed neuroendocrine-non-neuroendocrine neoplasms. All GIT NEN have the potential to synthesize and secrete various bioactive substances which may lead to various clinical syndromes. The NEN may occur anywhere in the GIT and exhibit varying clinical presentation, prognosis, and metastatic potential. Further, some tumors show association with familial syndromes like multiple endocrine neoplasia type 1 and neurofibromatosis type 1. Ultrasonography, computed tomography (CT), magnetic resonance imaging, and positron emission tomography-CT are the imaging modalities useful in the diagnosis, localization, and staging of GIT NEN. Management depends on the site, size, grade, and stage of the tumor with interventional radiology playing a significant role in some cases. This imaging review describes the role of a radiologist in the management of GIT NEN.

Multimodality Imaging of Neuroendocrine Tumors

Neuroendocrine tumors are rare solid tumors with an estimated 12,000 people in the United States diagnosed each year. Neuroendocrine tumors can occur in any part of the body. There is a wide spectrum of disease, ranging from slow-growing and indolent tumors found incidentally to highly aggressive malignancies with a poor prognosis. Knowledge of neuroendocrine tumor pathology is essential in the diagnostic workup of these patients. This article focuses on the evaluation, detection, and staging of common neuroendocrine tumors with multiple imaging modalities; the information gained with a multimodality approach is often complementary and leads to image-guided treatment decision making.

Solitary late metastasis of primary renal cell carcinoid tumor to the extraocular muscles imaged with indium-111 octreotide

A 75-year-old male presented with right eye pain and proptosis. His history was significant for renal cell carcinoma treated with left nephrectomy 2 years previously. Computed tomography (CT) imaging demonstrated a 1.6-cm enhancing lesion in the right retrobulbar space. Surgical biopsy revealed a low-grade metastatic carcinoid tumor. At retrospective review, the primary renal lesion from 2 years prior was rediagnosed as consistent with a renal carcinoid tumor. Indium-111 octreotide single photon emission CT/CT imaging demonstrated a solitary metastasis within the right extraocular muscles. The patient subsequently developed additional metastases within the remaining right kidney and lung.

Population-based assessment of patient and provider characteristics influencing pediatric outpatient antibiotic use in a high antibiotic-prescribing state

OBJECTIVE

To identify patient and provider characteristics associated with high-volume antibiotic prescribing for children in Tennessee, a state with high antibiotic utilization.

DESIGN

Cross-sectional, retrospective analysis of pediatric (aged <20 years) outpatient antibiotic prescriptions in Tennessee using the 2016 IQVIA Xponent (formerly QuintilesIMS) database.

METHODS

Patient and provider characteristics, including county of prescription fill, rural versus urban county classification, patient age group, provider type (nurse practitioner, physician assistant, physician, or dentist), physician specialty, and physician years of practice were analyzed.

RESULTS

Tennessee providers wrote 1,940,011 pediatric outpatient antibiotic prescriptions yielding an antibiotic prescribing rate of 1,165 per 1,000 population, 50% higher than the national pediatric antibiotic prescribing rate. Mean antibiotic prescribing rates varied greatly by county (range, 39-2,482 prescriptions per 1,000 population). Physicians wrote the greatest number of antibiotic prescriptions (1,043,030 prescriptions, 54%) of which 56% were written by general pediatricians. Pediatricians graduating from medical school prior to 2000 were significantly more likely than those graduating after 2000 to be high antibiotic prescribers. Overall, 360 providers (1.7% of the 21,798 total providers in this dataset) were responsible for nearly 25% of both overall and broad-spectrum antibiotic prescriptions; 20% of these providers practiced in a single county.

CONCLUSIONS

Fewer than 2% of providers account for 25% of pediatric antibiotic prescriptions. High antibiotic prescribing for children in Tennessee is associated with specific patient and provider characteristics that can be used to design stewardship interventions targeted to the highest prescribing providers in specific counties and specialties.

[Modern sonographic imaging of abdominal neuroendocrine tumors]

BACKGROUND

Radiological and nuclear medical diagnostics play an important role in the work-up of patients with gastroenteropancreatic neuroendocrine tumors (GEP-NET). The sonographic examination, including contrast-enhanced examination, depicts an initial imaging modality to screen for NET. This report describes the sonomorphological behavior of ileal and pancreatic NET as well as hepatic metastases from NET.

CLINICAL/METHODICAL ISSUE

Sonographic evaluation of NET of the small intestine, pancreas and neuroendocrine hepatic metastases.

STANDARD RADIOLOGICAL METHODS

Contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI), unenhanced ultrasonography.

METHODICAL INNOVATIONS

Contrast-enhanced ultrasound (CEUS).

PERFORMANCE

CEUS supports unenhanced ultrasound in the detection of NET and the differential diagnosis of unclear lesions, and is more sensitive for liver metastases (sensitivity according to the literature, 99% vs. 68%) PRACTICAL RECOMMENDATIONS: CEUS allows initial evaluation of NET and differentiation of benign vs. malignant lesions. Nevertheless, CEUS cannot replace more elaborate imaging modalities like CT or MRI for thorough staging examinations.

CT detection of primary and metastatic ileal carcinoid tumor: rates of missed findings and associated delay in clinical diagnosis

PURPOSE

To determine the rate of missed CT findings of ileal carcinoid tumor prior to pathologic diagnosis and the resultant diagnostic delay.

METHODS

Initially, 74 patients with abdominal and pelvic CT prior to pathologically-proven diagnosis of ileal carcinoid were identified. Patients were excluded when the original CT study (n = 6) or report (n = 4) was not available, resulting in a final cohort of 64 patients (mean age, 58.3 years; 29 M/35F); 27 (42%) patients had more than one abdominal CT prior to diagnosis. All available CT studies prior to diagnosis were retrospectively reviewed for the presence of the primary ileal tumor and metastatic disease (mesenteric and hepatic).

RESULTS

Primary ileal tumors were prospectively missed on at least one CT scan in 64% (32/50) of patients with retrospectively identifiable disease. CT findings of mesenteric spread were missed at least once in 46% (25/54) of cases where present in retrospect. By the final pre-operative CT, hepatic metastases and bowel wall thickening were present in 55% (35/64) and 52% (33/64) of cases, respectively. In patients with missed ileal and/or mesenteric findings resulting in diagnostic delay, mean delay was 40 months (range 4-98 months).

CONCLUSION

Initial presentation of ileal carcinoid tumor, even with mesenteric involvement, is often missed prospectively at abdominal CT, leading to delay in diagnosis until bowel or mesenteric findings become more obvious, or hepatic metastatic disease manifests. Radiologists should make a concerted effort to evaluate the bowel and mesentery in patients with long-standing vague abdominal symptoms.

Demystifying the mesenteric root lesions

OBJECTIVE

The aim of this article is to describe the normal anatomy of the root of the small bowel mesentery (RSBM) as well as the multidetector computed tomography (MDCT) features of the various primary and secondary lesions that affect the RSBM.

RESULTS

The small bowel mesentery attaches the jejunum and ileum to the posterior abdominal wall, the line of attachment forming the RSBM. Several primary as well as secondary lesions involve the RSBM. The RSBM has anatomical contiguity with the mesocolon and other peritoneal ligaments, which forms a route for the spread of infection, neoplasms as well as several other abdominal pathologies. MDCT plays an important role in the evaluation of mesenteric root lesions.

CONCLUSION

Familiarity with the lesions involving the RSBM and their characteristic appearances on MDCT is important in giving thoughtful differential diagnosis and guiding the treating physician in further management.

A case of pseudocystic liver metastases from an atypical lung carcinoid tumor

Metastatic neuroendocrine tumors of the liver typically appear as solid, hypervascular masses on imaging. Pseudocysts mimicking simple cysts are extremely rare. A 42-year-old Japanese woman was referred with a single pulmonary mass in the left lower lobe. No metastatic lesion was detected and no occupying lesion in the liver was observed. The lung tumor was diagnosed as an atypical carcinoid. Postoperative investigation revealed new hepatic simple cysts in the liver, which increased in size over time and changed into hemorrhagic cysts. Fluorodeoxyglucose positron emission tomography and somatostatin receptor scintigraphy using 111In-octreotide demonstrated no accumulation in the liver. Our patient did not have symptoms consistent with carcinoid syndrome. The patient underwent partial resection of the cystic lesions of the liver. Gross examination of the tumors demonstrated thin-wall cavitated lesions with hemorrhage which were metastases from the atypical carcinoid of the lung. When a growing cystic lesion with intracystic hemorrhage is found in the liver of a patient with a history of carcinoid tumors, pseudocysts caused by degeneration of a carcinoid metastasis should be considered as a differential diagnosis.

Multimodality Imaging of Ileal Neuroendocrine (Carcinoid) Tumor

OBJECTIVE. The purpose of this article is to provide a multimodality imaging review of ileal carcinoid tumor. CONCLUSION. Ileal carcinoid tumors display a variety of radiologic findings. Delay in diagnosis is common because of initial nonspecific symptoms and subtle imaging findings. Reviewing the multimodality imaging appearance of the primary tumor, metastatic disease, and associated ancillary findings can help improve patient care.

Extra-pulmonary primary small-cell neuroendocrine carcinoma arising from the duodenum: rare tumor, unusual location

Small‐cell neuroendocrine carcinoma is a high‐grade carcinoma rarely encountered in extra‐pulmonary sites. A 40‐year‐old lady presented with epigastric pain and was noted to have an ulcerated small‐cell neuroendocrine carcinoma in her duodenum with liver metastases. She underwent palliative chemotherapy but unfortunately passed away. Duodenal SCNC is an unusual malignancy with an aggressive phenotype.

The role of pre-operative imaging and double balloon enteroscopy in the surgical management of small bowel neuroendocrine tumors: Is it necessary?

BACKGROUND AND OBJECTIVES

Pre-operative localization of small bowel neuroendocrine tumors (SBNET) is important for operative planning. The aim was to determine the effectiveness of pre-operative imaging and double-balloon enteroscopy (DBE) in identifying extent of disease.

METHODS

Database review identified 85 patients with primary SBNET between 2006 and 2013. Analysis included patients who underwent imaging, endoscopy, and surgery at our institution.

RESULTS

Average age was 60.7 years. Sixty-six (77.1%) patients had a primary NET in the ileum. Seventy-two patients (67.3%) underwent CT, 47 (46.7%) had MRI, 44 (46.7%) had somatostatin receptor imaging (SRI), and 41 (39.3%) underwent DBE. The sensitivity of each in identifying the NET was 59.7% for CT, 54% for MRI, 56% for SRI, and 88.1% for DBE. Eighteen (21.2%) patients had primary tumors not identified on imaging. Of these 18, 13 underwent DBE, and 12 of 13 (92.3%) DBEs identified the primary lesion. DBE was significantly better at identifying the primary NET than CT, MRI or SRI (P = 0.004, 0.007, and 0.012).

CONCLUSIONS

Most SBNETs are identified with a combination of imaging modalities. In those with unidentified primary tumors after imaging, DBE should be considered as it may provide valuable information as to the location of the primary tumor.

Primary hepatic neuroendocrine tumors: multi-modal imaging features with pathological correlations

BACKGROUND

Primary hepatic neuroendocrine carcinomas (PHNECs) are rare and asymptomatic, and are therefore difficult to distinguish radiologically from other liver carcinomas. In this study, we aimed to determine the computed tomography (CT), magnetic resonance imaging (MRI), and digital subtraction angiography (DSA) features of PHNECs.

METHODS

A retrospective analysis of 11 patients with pathologically proven PHNECs was performed from January 2009 to September 2014. The CT, MRI, and DSA image features were analysed.

RESULTS

Ten of the eleven patients exhibited two or more lesions, and one patient exhibited a single lesion. Abdominal CT of 8 cases revealed multiple round or oval-shaped masses with well-defined borders, which were heterogeneous and hypodense on precontrast CT images. Significant diffuse heterogeneous enhancement was observed during the arterial phase in 8 cases, and the enhancement was slightly higher than the attenuation of the surrounding normal liver parenchyma and indistinct edges of small lesions during the portal phase. Well circumscribed (11 cases), lobulated (5 cases) or multiple nodular masses (4 cases), nodule (1 case) and irregular masses (1 case) of high signal intensity were observed on T2WI and DWI of MR images. The masses were well circumscribed, heterogeneous, and hypointense on T1WI, with significant enhancement of the solid carcinoma portion in the early arterial phase and continued enhancement in the portal venous phase. Characteristic lobulated or multiple nodular masses were observed in MRI. DSA showed multiple hypervascular carcinoma-staining lesions with sharp edges in the arterial phase.

CONCLUSION

The CT, MRI, and DSA images of PHNECs exhibit specific characteristic features. Appropriate combinations of the available imaging modalities could therefore optimize the evaluation of patients with PHNECs.

Sarcoidosis mimicking metastatic progression of pancreatic neuroendocrine tumor: A case report

RATIONALE

Pancreatic neuroendocrine tumors (PNETs) account for less than 5% of all pancreatic tumors. PNETs develop from pancreatic endocrine islet cells and have a variable range of malignant potential. These neoplasms tend to have a slower growth rate than exocrine tumors and may remain undetectable for years. Achieving a correct diagnosis and staging is of key importance for the optimal management of the disease and requires experience with the disease, an accurate clinical status evaluation and a critical interpretation of the radiological findings derived from morphological and functional imaging techniques as well as an integrated multidisciplinary approach. The possibility that some clinical data and radiological findings encountered during the diagnostic and staging procedures may not be related to PNETs but to concomitant clinical conditions should always be taken into consideration. This is mandatory as an incorrect stadiation may lead to patients' mis-management.

PATIENT CONCERNS

We report the case of a 34-year-old female, with a past medical history of idiopathic acute pancreatitis, presenting with a severe upper abdominal pain, steady and radiating to the back.

DIAGNOSES

Initial investigations incidentally detected a nonfunctioning pancreatic neuroendocrine tumor (NF-PNET) of intermediate grade G2. Subsequent investigations aimed at determining a correct tumor staging showed a negative indium-111- OctreoScan but an increased 18F-labeled fluorodesossiglucose (18F-FDG) uptake in multiple bilateral nodules in the lungs and in 1 nodular lesion located in the right gluteal subcutaneous tissue. An early tumor progression of a G2 NF-PNET that had to be treated with chemotherapy was suspected.

INTERVENTIONS

The histological examination of the gluteal subcutaneous nodule showed noncaseating granulomas, disproving the initial clinical suspect and allowing the diagnosis of active sarcoidosis in the G2 NF-PNET patient.

LESSONS

A misdiagnosis and a consequent therapeutic mismanagement were avoided with the support of an integrated multidisciplinary team.

Primary lung carcinoid metastatic to the breast

Lung carcinoid tumors account for approximately 2% of lung cancers, with 10% of the tumors represented by the atypical type. While atypical carcinoids are metastatic to intrathoracic lymph nodes in approximately half of the cases on the initial presentation, distant metastases are seen in only 20% of the patients and are found most frequently in bones, liver, adrenal glands, and brain. We present a case of an unusual metastatic disease to the breast in 51-year-old female who developed a new breast mass 2 years after left lower lobectomy due to atypical carcinoid tumor. Atypical pulmonary carcinoid metastases to the breast are exceptionally uncommon, yet they are important considerations for appropriate management, especially with an anamnesis of this neoplasm.

Pediatric Neuroendocrine Carcinoid Tumors: Review of Diagnostic Imaging Findings and Recent Advances

OBJECTIVE

Although rare, pediatric neuroendocrine tumors including carcinoid tumor have increased in incidence over the past few decades. Despite increased recognition, survival rates have not significantly improved. Earlier detection of these tumors is necessary to improve clinical outcomes. This article discusses imaging approaches for detecting pediatric carcinoid tumors including anatomic imaging methods such as CT and MRI as well as functional imaging methods targeting the somatostatin receptor including ¹¹¹In-labeled octreotide and newer ⁶⁸Ga-based radiotracers that may hold promise in hybrid PET/CT or PET/MRI.

CONCLUSION

Improvements in functional imaging with novel somatostatin receptor-specific radiotracers along with fused functional and anatomic imaging have substantially improved the clinical detection of carcinoid tumors. Although rare, these tumors are encountered in children, and an awareness of the appropriate use of various imaging methods is essential for pediatric specialists. Further research is needed to ascertain the diagnostic value of newer imaging methods and radiotracer-based treatment approaches, especially in the pediatric population.

An Incidental Solitary Plasmacytoma of Bone Mimicking Neuroendocrine Tumor Metastasis on 68Ga-DOTATATE Positron Emission Tomography/Computed Tomography

A 54-year-old woman with suspicion of neuroendocrine tumor (NET) was referred for ⁶⁸Ga-DOTATATE positron emission tomography/computed tomography (CT) imaging due to clinical findings. A well-defined osteolytic lesion on the corpus of the third lumbar vertebra was evident on CT images with mild uptake of ⁶⁸Ga-DOTATATE, which led to suspicion of NET metastasis. Histopathologic examination revealed solitary plasmacytoma of the bone. The patient received local external radiotherapy for plasmacytoma. This case indicatesthat other diseases expressing somatostatin receptors may be inaccurately reported as tumor recurrence and highlights the importance of meticulous evaluation of positive findings.

Systematic review reveals lack of quality in reporting health-related quality of life in patients with gastroenteropancreatic neuroendocrine tumours

BACKGROUND

Gastroenteropancreatic neuroendocrine tumours (GEP-NET) are often slow-growing and patients may live for years with metastasised disease. Hence, along with increasing overall and progression-free survival, treatments aim at preserving patients' well-being and health-related quality of life (HRQoL). However, studies on systematic HRQoL assessment in patients with GEP-NET are scarce. Therefore, the purpose of the current review is to systematically evaluate the methodological quality of the identified studies.

METHODS

A targeted database search was performed in PubMed, EMBASE, and CENTRAL. Data extraction was conducted by two independent researchers according to predefined criteria. For study evaluation, the Minimum Standard Checklist for Evaluating HRQoL Outcomes in Cancer Clinical Trials and the CONSORT Patient-Reported Outcome extension were adapted.

RESULTS

The database search yielded 48 eligible studies. We found the awareness for the need of HRQoL measurement to be growing and application of cancer-specific instruments gaining acceptance. Overall, studies were too heterogeneous in terms of patient characteristics and treatment interventions to draw clear conclusions for clinical practice. More importantly, a range of methodological shortcomings has been identified which were mainly related to the assessment and statistical analysis, as well as the reporting and interpretation of HRQoL data.

CONCLUSION

Despite an increasing interest in HRQoL in GEP-NET patients, there is still a lack of knowledge on this issue. A transfer of HRQoL results into clinical practice is hindered not only by the scarceness of studies, but also by the often limited quality of HRQoL processing and reporting.

A rare case of a primary hepatic neuroendocrine tumor

Neuroendocrine tumors are well-differentiated low grade malignant neoplasms. Their pathogenesis is thought to be secondary to the unrestricted proliferation of neuroendocrine cells. They most commonly arise in the bronchopulmonary or gastrointestinal tract but can originate from almost any organ. While the liver is a common site of metastases, primary hepatic neuroendocrine tumors are an exceedingly rare pathology, of which fewer than 100 cases have been described in world literature. Thus, there exists a paucity of data regarding the clinical presentation, diagnosis and management of this disease. We present a case of a 35-year-old patient who presented to our facility for evaluation of a cough and cervical lymphadenopathy. Two biopsies of the lymph nodes were negative, however on workup for an occult malignancy a hypodense heterogeneous hypervascular lesion measuring 3.7 cm × 2.7 cm in segment IVb of the liver was noted on computer tomography (CT) scan. The levels of laboratory studies such as liver enzymes, alkaline phospatase, chromogranin A, 24-hour 5 hydroxyindoleacetic acid (5-HIAA) and tumor markers including alpha fetoprotein were not elevated. An MRI confirmed the mass, and the patient underwent CT guided biopsy of the hepatic lesion. Staining from the biopsy resulted in cells reactive for synaptophysin, chromogranin, anti-Cytokeratin (CAM 5.2), MOC31, CD 56 and mucin glycoprotein (MUC) confirming a nonsecretory neuroendocrine tumor. Patient underwent octreotide scan, PET scan, CT chest, MRI head along with EUS, EGD and colonoscopy to evaluate for a primary source, however, none was found. The well localized presentation without extensive hepatic invasion made the patient a candidate for surgical resection which was successfully performed. The patient remains disease free over 36 months after initial presentation. Primary hepatic neuroendocrine tumors are an exceedingly rare entity whose variable presentation necessitates provider familiarity with this condition. Once identified, excluding other primary locations with thorough investigation and treatment with surgical resection has been shown to provide the most patient benefit.

Case Report of Contrast-Enhanced Ultrasound Features of Primary Hepatic Neuroendocrine Tumor: A CARE-Compliant Article

Primary hepatic neuroendocrine tumors (PHNETs) are very rare and their clinical features and treatment outcomes are not well understood. It is difficult to reach a proper diagnosis before biopsy or resection. The aim of this study was to analyze the imaging features of PHNETs on contrast-enhanced ultrasound (CEUS). The clinical characteristics, CEUS findings, pathological features, treatment and prognosis of 6 patients with PHNET treated in our hospital were retrospectively analyzed.Most PHNETs occurred in middle-aged patients, and the most common clinical manifestation was right upper quadrant palpable mass and abdominal pain. Multiple small anechoic intralesional cavities occurred frequently in PHNET. Multilocular cystic with internal septation or monolocular with wall nodule could also be detected. On contrast-enhanced ultrasonography (CEUS), heterogeneous hyperenhancement in the arterial phase and wash-out hypoenhancement were observed in most patients, while computed tomography scanning yielded similar results. Diagnosis of PHNET was confirmed by immunohistochemical result and follow-up with the absence of extrahepatic primary sites. Five patients received surgical resection and 2 cases exhibited recurrence. Transcatheter arterial chemoembolization was performed in 1 patient with recurrence. Only 1 patient received conservative care. The median overall survival in 5 patients who underwent surgical treatment was 27 months (18-36 months). PHNET is a rare tumor, and its diagnosis is difficult. The CEUS features reported in this series may enrich the knowledge base for characterization of PHNET.

Duodenal neuroendocrine tumors: retrospective evaluation of CT imaging features and pattern of metastatic disease on dual-phase MDCT with pathologic correlation

PURPOSE

The purpose of the study is to evaluate the CT appearance and pattern of metastatic disease of patients with surgically resected well-differentiated duodenal neuroendocrine tumors who underwent pre-operative dual-phase CT.

METHODS

Clinical and pathologic records and CT images of 28 patients (average age 58.0 years) following Whipple procedure were retrospectively reviewed. The size, morphology (polypoid, intraluminal mass or wall thickening, intramural mass), location, CT attenuation in the arterial and venous phases, and the presence of lymph node or liver metastases were recorded.

RESULTS

On CT, 19 patients (67.8%) had neuroendocrine tumors manifested as polypoid or intraluminal masses (38 lesions, multiple tumors in 3 patients), 4 patients (14.3%) had tumors manifested as wall thickening or intramural masses, and in 5 patients (17.9%), the primary tumor was not visualized. Lesions not seen at CT were less than 0.8 cm on pathologic diagnosis. The mean size of polypoid tumors on CT was 1.2 cm (range 0.3-3.8 cm); 24 tumors were 1.0 cm or smaller, and 14 tumors were larger than 1.0 cm. Most lesions were hypervascular in the arterial phase (19/23 patients) with an increase in tumor enhancement in the venous phase in 14 patients (60.9%), decrease in enhancement in 7 patients (30.4%), and no change in enhancement in 2 patients (8.7%). Thirteen patients (46.4%) had metastatic disease from carcinoid tumor, most commonly regional enhancing lymphadenopathy.

CONCLUSION

Duodenal carcinoid tumors commonly appear as an enhancing mass in either the arterial or venous phases. If a primary tumor is not seen in the duodenum, adjacent enhancing lymphadenopathy can be a clue to the presence of a duodenal carcinoid tumor.

De-misty-fying the mesentery: an algorithmic approach to neoplastic and non-neoplastic mesenteric abnormalities

Mesenteric abnormalities are often incidentally discovered on cross-sectional imaging performed during daily clinical practice. Findings can range from the vague "misty mesentery" to solid masses, and the possible etiologic causes encompass a wide spectrum of underlying pathologies including infectious, inflammatory, and neoplastic processes. Unfortunately, the clinical and imaging findings are often non-specific and may overlap. This article discusses the various diseases that result in mesenteric abnormalities. It provides a framework to non-invasively differentiate these entities, when possible.

Case 227: Endobronchial Carcinoid Tumor with Incidental Metastatic Breast Cancer Detected with Somatostatin Receptor Scintigraphy ((111)In Pentreotide)

HISTORY

A 30-year-old woman with polycystic ovarian syndrome who was undergoing hormone replacement therapy presented with a 6-month history of a nonproductive cough and a 1-day history of hemoptysis (approximately 20 mL). Intravenous contrast material-enhanced (100 mL of Omnipaque 350; GE Healthcare, Princeton, NJ) computed tomographic (CT) pulmonary angiography was performed to evaluate for pulmonary embolism. On the basis of the CT pulmonary angiographic findings, chromogranin A and 5-hydroxyindoleacetic acid levels were measured and were 7 nmol/L (343 µg/L) (high) and 2.9 mg per 24 hours (15.167 µmol/d) (normal), respectively. This patient underwent bronchoscopy and biopsy. After these tests, she was referred for whole-body scintigraphy, which revealed an unexpected finding that was further investigated with fluorine 18 ((18)F) flurodeoxyglucose (FDG) positron emission tomography (PET) and CT.

Bronchopulmonary Neuroendocrine Neoplasms and Their Precursor Lesions in Multiple Endocrine Neoplasia Type 1

OBJECTIVE

The prevalence and clinical behavior of bronchopulmonary neuroendocrine tumors (bNET) associated with multiple endocrine neoplasia type 1 (MEN1) are not well defined. This study aimed to determine the prevalence, potential precursor lesions and prognosis of bNET in patients with MEN1.

METHODS

A database of 75 prospectively collected MEN1 cases was retrospectively analyzed for bNET. Patient characteristics, imaging and treatment were evaluated. Resection specimens of operated patients were reassessed by two specialized pathologists. Available CT scans of the whole cohort were reviewed to determine the prevalence of bronchopulmonary nodules.

RESULTS

Five of the 75 MEN1 patients (6.6%; 2 male, 3 female) developed histologically confirmed bNET after a median follow-up of 134 months. The median age at diagnosis of bNET was 47 years (range 31-67), and all patients were asymptomatic. Four patients underwent anatomic lung resections with lymphadenectomy; the remaining patient with multiple lesions had only a wedge resection of the largest bNET. Tumor sizes ranged from 7 to 32 mm in diameter, and all bNET were well differentiated. Two patients had lymph node metastases. Two of 4 reevaluated resection specimens revealed multifocal bNET, and 3 specimens showed tumorlets (up to 3) associated with multifocal areas of a neuroendocrine cell hyperplasia within the subsegmental bronchi. One bNET-related death (1.3%) occurred during long-term follow-up. Review of the available CT scans of the patients without proven bNET revealed small bronchopulmonary lesions (≥3 mm) in 16 of 53 cases (30.2%).

CONCLUSIONS

bNET in MEN1 might be more common than previously recognized. Their natural course seems to be rather benign. Multifocal tumorlets and multifocal neuroendocrine cell hyperplasia might represent their precursor lesions.

Role of computed tomography angiography in detection and staging of small bowel carcinoid tumors

Small-bowel carcinoid tumors are the most common form (42%) of gastrointestinal carcinoids, which by themselves comprise 70% of neuroendocrine tumors. Although primary small bowel neoplasms are overall rare (3%-6% of all gastrointestinal neoplasms), carcinoids still represent the second most common (20%-30%) primary small-bowel malignancy after small bowel adenocarcinoma. Their imaging evaluation is often challenging. State-of-the-art high-resolution multiphasic computed tomography together with advanced postprocessing methods provides an excellent tool for their depiction. The manifold interactive parameter choices however require knowledge of when to use which technique. Here, we discuss the imaging appearance and evaluation of duodenal, jejunal and ileal carcinoid tumors, including the imaging features of the primary tumor, locoregional mesenteric nodal metastases, and distant metastatic disease. A protocol for optimal lesion detection is presented, including the use of computed tomography enterography, volume acquisition, computed tomography angiography and three-dimensional mapping. Imaging findings are illustrated with a series of challenging cases which illustrate the spectrum of possible disease in the small bowel and mesentery, the range of possible appearances in the bowel itself on multiphase data and extraluminal findings such as the desmoplastic reaction in mesentery and hypervascular liver metastases. Typical imaging pitfalls and pearls are illustrated.

An Unusual Location of Neuroendocrine Tumour: Primary Hepatic Origin

Although neuroendocrine tumours (NETs) of primary hepatic origin are extremely rare, most of NETs present with liver metastasis. When a NET is found in the liver, it must be treated to exclude metastasis from extrahepatic primary sites. The patient was a 38-year-old female. Abdominal ultrasound showed an 8 cm tumour in liver during a routine examination. Liver biopsy was done. The tumour was first considered a metastatic hepatic tumour on histopathological examination. No clues to the origin of a primary tumour were found. Upper and lower endoscopy of the GI tract and chest CT were performed to search for a primary tumour and were negative for any tumour. One month later, more extensive areas of the tumour were seen on histopathological examination of second liver biopsy with the same morphologic characteristics as the first biopsy. Immunohistochemically, there was positive staining for synaptophysin, CD 56, and S-100 in the tumour cells. These findings suggested the diagnosis of NET. The diagnosis of primary liver NET was considered in a multidisciplinary meeting. Then, left hepatectomy was performed. The final pathologic diagnosis of the tumour in the resected liver specimen was Grade II NET. The patient was doing well at postoperative 28-month follow-up.

Primary hepatic neuroendocrine tumor with multiple liver metastases: A case report with review of the literature

We herein present a case involving a 41-year-old woman in whom ultrasound examination revealed multiple liver hemangiomas more than 3 years ago. Follow-up ultrasound examination revealed that the masses had significantly increased; the largest was located in the right lobe (about 8.2 cm × 7.4 cm × 6.0 cm). Abdominal multidetector computed tomography revealed multiple well-circumscribed, heterogeneous, hypodense masses (largest, 6.4 cm × 6.3 cm × 5.0 cm) with significant contrast enhancement during the arterial and portal phases and with contrast wash-out and peripheral enhancement during the delayed phases. Magnetic resonance images demonstrated multiple well-circumscribed, heterogeneous, hypointense hepatic masses with significant contrast enhancement (largest, 6.4 cm × 6.5 cm × 5.1 cm); multiple enlarged porta lymph nodes; and multiple slightly enlarged retroperitoneal lymph nodes. Histological and immunohistochemical examination of the right mass biopsy specimen suggested a malignant neoplasm that had originated from a neuroendocrine cell type (grade 2 well-differentiated neuroendocrine carcinoma). After performing a systemic examination to exclude metastasis from an extrahepatic primary site, we considered that the masses had arisen from a primary hepatic neuroendocrine tumor with multiple liver metastases. The patient underwent transcatheter arterial chemoembolization using a combination of oxaliplatin (150 mg) mixed with one bottle of gelatin sponge particles (560-710 μm) and lipiodol (6 mL). Primary neuroendocrine tumors of the liver are extremely rare. This case is interesting because of the rarity of this neoplasm and previous misdiagnosis as multiple liver hemangiomas. Previously reported cases in the literature are also reviewed.

Should mesenteric tumor deposits be included in staging of well-differentiated small intestine neuroendocrine tumors?

Well-differentiated small intestine neuroendocrine tumors can give rise to mesenteric tumor deposits, which are not included in the current American Joint Committee on Cancer staging system for small intestine neuroendocrine tumors, and their impact on patient prognosis is unknown. Seventy-two small intestine neuroendocrine tumors resections were identified in our files with slides, reports, and follow-up data available. Cases were assessed for T-category and for the presence of mesenteric tumor deposits, lymph node metastases, lymphovascular invasion, and liver metastases. Mesenteric tumor deposits were defined as discrete mesenteric tumor nodules ≥1 mm with an irregular growth profile. Similar lesions clearly resulting from extranodal extension or direct contiguous spread by the primary lesion were excluded. Forty-three of the 72 cases had mesenteric tumor deposits (60%). The deposits were significantly associated with lymphovascular invasion (P=0.001), pT3 or pT4 disease (P=0.001), nodal metastases (P=0.040), and liver metastases (P<0.001) at the time of surgery. In addition, four of six cases with tumor deposits and no nodal disease had liver disease. Tumor deposits were associated with an increased incidence of disease progression and death due to the disease (P=0.001). Finally, the presence of tumor deposits at the time of surgery was associated with an increase in hazard of progression or death due to disease (hazard ratio: 4.0; 95% confidence interval: 1.3, 12.5; P=0.016). Mesenteric tumor deposits are present in the majority of cases of small intestine neuroendocrine tumors and are indicators of poor prognosis for this disease. Therefore, they may have a place in staging of small intestine neuroendocrine tumors, perhaps as analogous to lymph node disease.

Case 200: Gastric enterochromaffinlike cell tumors in a patient with type 1 multiple endocrine neoplasia

History A 55-year-old man presented with chronic epigastric pain lasting for about 1 year and without fever or vomiting. The abdomen was soft and tender at physical examination. Laboratory tests revealed unremarkable liver function, normal hemoglobin level, and normal amylase level. White blood cell count was normal, and there was no inflammatory syndrome. The patient's medical history included pancreatic gastrinoma resected by means of left pancreatectomy 31 years before, hyperparathyroidism treated with subtotal parathyroidectomy 24 years before, and a slowly growing lung mass known for 9 years. Esophagogastroduodenoscopy was performed because of a suspected gastroduodenal ulcer. The results showed numerous small (<10 mm) gastric and duodenal ulcers and multiple 10-15-mm polypoid gastric masses. Contrast material-enhanced dual-phase multidetector row computed tomography (CT) of the chest and abdomen was performed with a 64-section CT scanner (LightSpeed VCT; GE Healthcare, Milwaukee, Wis). Technical parameters for CT were as follows: pitch, 0.98; section thickness and reconstruction interval, 1.25 mm; 120 kVp; and variable milliamperage determined by x-, y-, and z-axis dose modulation. After an unenhanced abdominal scan, iobitridol, a nonionic iodinated contrast agent containing 350 mg of iodine per milliliter (Xenetix 350; Guerbet, Aulnay-sousbois, France), was administered intravenously through a 16-18-gauge catheter. A 120-mL dose of the contrast agent was injected via an antecubital vein at a rate of 4 mL/sec. No oral contrast medium was administered. After preliminary unenhanced abdominal scanning, arterial and portal venous phase acquisitions were obtained 45 and 80 seconds after initiation of contrast medium injection.

Free somatostatin receptor fraction predicts the antiproliferative effect of octreotide in a neuroendocrine tumor model: implications for dose optimization

Somatostatin receptors (SSTR) are highly expressed in well-differentiated neuroendocrine tumors (NET). Octreotide, an SSTR agonist, has been used to suppress the production of vasoactive hormones and relieve symptoms of hormone hypersecretion with functional NETs. In a clinical trial, an empiric dose of octreotide treatment prolonged time to tumor progression in patients with small bowel neuroendocrine (carcinoid) tumors, irrespective of symptom status. However, there has yet to be a dose optimization study across the patient population, and methods are currently lacking to optimize dosing of octreotide therapy on an individual basis. Multiple factors such as total tumor burden, receptor expression levels, and nontarget organ metabolism/excretion may contribute to a variation in SSTR octreotide occupancy with a given dose among different patients. In this study, we report the development of an imaging method to measure surface SSTR expression and occupancy level using the PET radiotracer (68)Ga-DOTATOC. In an animal model, SSTR occupancy by octreotide was assessed quantitatively with (68)Ga-DOTATOC PET, with the finding that increased occupancy resulted in decreased tumor proliferation rate. The results suggested that quantitative SSTR imaging during octreotide therapy has the potential to determine the fractional receptor occupancy in NETs, thereby allowing octreotide dosing to be optimized readily in individual patients. Clinical trials validating this approach are warranted.

Primary carcinoid tumor of the cavernous sinus

BACKGROUND

Intracranial carcinoid tumors belong to the class of neuroendocrine tumors and their incidence is extremely rare. The pathogenesis and clinical manifestations of carcinoid tumors of the skull base are outlined in this case report.

CASE DESCRIPTION

A 61-year-old multimorbid woman presented with transient memory loss. Computed tomographic and magnetic resonance imaging scan of the brain demonstrated a left cavernous sinus mass extending into the infratemporal fossa. The lesion was biopsied using the Caldwell-Luc approach, and histology showed a low-grade neuroendocrine tumor. The tumor was subtotally resected with a neurosurgery/head and neck combined preauricular infratemporal and subtemporal extradural approaches to the cavernous sinus. Further histologic evaluation revealed that the tumor was of carcinoid differentiation with no other primary or metastatic sites detectable.

CONCLUSION

Primary intracranial carcinoid tumors, though rare, should be included in the differential diagnosis of extradural and dural-based lesions.

A spectrum of SPECT/CT image fusion applications in daily clinical practice

Direct multimodality image correlation optimizes interpretation and diagnostic confidence, thereby enriching the radiologist's role in guiding clinical management. The primary advantages of SPECT/CT image fusion are more accurate identification and localization of disease and improved specificity. As illustrated here, software-based SPECT/CT image fusion enhances diagnosis for a variety of clinical presentations using the armamentarium of common radiopharmaceuticals, but without the costs of hybrid systems.

Primary hepatic neuroendocrine tumor: gadoxetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging

We present a case of a 71-year-old man with prostate cancer who had no prior underlying liver disease. During metastatic evaluation, a solid mass in the liver was identified by computed tomography and ultrasound. Gadoxetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging demonstrated a well-defined, peripheral enhancing hepatic mass containing small cystic component. This lesion was diagnosed as hepatic neuroendocrine tumor. Primary neuroendocrine tumors of the liver are extremely rare. This case is interesting because of the rarity of this neoplasm and the unique radiologic findings despite its small size. Reviews of previously reported cases in the literature are also presented.

Staging of neuroendocrine tumours: comparison of [⁶⁸Ga]DOTATOC multiphase PET/CT and whole-body MRI

Purpose: In patients with a neuroendocrine tumour (NET), the extent of disease strongly influences the outcome and multidisciplinary therapeutic management. Thus, systematic analysis of the diagnostic performance of the existing staging modalities is necessary. The aim of this study was to compare the diagnostic performance of 2 whole-body imaging modalities, [⁶⁸Ga]DOTATOC positron emission tomography (PET)/computed tomography (CT) and magnetic resonance imaging (MRI) in patients with NET with regard to possible impact on treatment decisions. Materials and methods: [⁶⁸Ga]DOTATOC-PET/CT and whole-body magnetic resonance imaging (wbMRI) were performed on 51 patients (25 females, 26 males, mean age 57 years) with histologically proven NET and suspicion of metastatic spread within a mean interval of 2.4 days (range 0–28 days). PET/CT was performed after intravenous administration of 150 MBq [⁶⁸Ga]DOTATOC. The CT protocol comprised multiphase contrast-enhanced imaging. The MRI protocol consisted of standard sequences before and after intravenous contrast administration at 1.5 T. Each modality (PET, CT, PET/CT, wbMRI) was evaluated independently by 2 experienced readers. Consensus decision based on correlation of all imaging data, histologic and surgical findings and clinical follow-up was established as the standard of reference. Lesion-based and patient-based analysis was performed. Detection rates and accuracy were compared using the McNemar test. P values <0.05 were considered significant. The impact of whole-body imaging on the treatment decision was evaluated by the interdisciplinary tumour board of our institution. Results: 593 metastatic lesions were detected in 41 of 51 (80%) patients with NET (lung 54, liver 266, bone 131, lymph node 99, other 43). One hundred and twenty PET-negative lesions were detected by CT or MRI. Of all 593 lesions detected, PET identified 381 (64%) true-positive lesions, CT 482 (81%), PET/CT 545 (92%) and wbMRI 540 (91%). Comparison of lesion-based detection rates between PET/CT and wbMRI revealed significantly higher sensitivity of PET/CT for metastatic lymph nodes (100% vs 73%; P < 0.0001) and pulmonary lesions (100% vs 87%; P = 0.0233), whereas wbMRI had significantly higher detection rates for liver (99% vs 92%; P < 0.0001) and bone lesions (96% vs 82%; P < 0.0001). Of all 593 lesions, 22 were found only in PET, 11 only in CT and 47 only in wbMRI. The patient-based overall assessment of the metastatic status of the patient showed comparable sensitivity of PET/CT and MRI with slightly higher accuracy of PET/CT. Patient-based analysis of metastatic organ involvement revealed significantly higher accuracy of PET/CT for bone and lymph node metastases (100% vs 88%; P = 0.0412 and 98% vs 78%; P = 0.0044) and for the overall comparison (99% vs 89%; P < 0.0001). The imaging results influenced the treatment decision in 30 patients (59%) with comparable information from PET/CT and wbMRI in 30 patients, additional relevant information from PET/CT in 16 patients and from wbMRI in 7 patients. Conclusion: PET/CT and wbMRI showed comparable overall lesion-based detection rates for metastatic involvement in NET but significantly differed in organ-based detection rates with superiority of PET/CT for lymph node and pulmonary lesions and of wbMRI for liver and bone metastases. Patient-based analysis revealed superiority of PET/CT for NET staging. Individual treatment strategies benefit from complementary information from PET/CT and MRI.

Clinical practice guidelines for multiple endocrine neoplasia type 1 (MEN1)

OBJECTIVE

The aim was to provide guidelines for evaluation, treatment, and genetic testing for multiple endocrine neoplasia type 1 (MEN1).

PARTICIPANTS

The group, which comprised 10 experts, including physicians, surgeons, and geneticists from international centers, received no corporate funding or remuneration.

PROCESS

Guidelines were developed by reviews of peer-reviewed publications; a draft was prepared, reviewed, and rigorously revised at several stages; and agreed-upon revisions were incorporated.

CONCLUSIONS

MEN1 is an autosomal dominant disorder that is due to mutations in the tumor suppressor gene MEN1, which encodes a 610-amino acid protein, menin. Thus, the finding of MEN1 in a patient has important implications for family members because first-degree relatives have a 50% risk of developing the disease and can often be identified by MEN1 mutational analysis. MEN1 is characterized by the occurrence of parathyroid, pancreatic islet, and anterior pituitary tumors. Some patients may also develop carcinoid tumors, adrenocortical tumors, meningiomas, facial angiofibromas, collagenomas, and lipomas. Patients with MEN1 have a decreased life expectancy, and the outcomes of current treatments, which are generally similar to those for the respective tumors occurring in non-MEN1 patients, are not as successful because of multiple tumors, which may be larger, more aggressive, and resistant to treatment, and the concurrence of metastases. The prognosis for MEN1 patients might be improved by presymptomatic tumor detection and undertaking treatment specific for MEN1 tumors. Thus, it is recommended that MEN1 patients and their families should be cared for by multidisciplinary teams comprising relevant specialists with experience in the diagnosis and treatment of patients with endocrine tumors.

Cross-Sectional Imaging of Small Bowel Malignancies

Small bowel malignancies are rare neoplasms, usually inaccessible to conventional endoscopy but detectable in many cases by cross-sectional imaging. Modern multidetector computed tomographies permit accurate diagnosis, complete pretreatment staging, and follow-up of these lesions. In this review, we describe the cross-sectional imaging features of the most frequent histologic subtypes of the small bowel malignancies.

[Multidetector computed tomography assessment of the degree of differentiation of bronchial carcinoid tumors]

OBJECTIVE

To define the CT findings for bronchial carcinoid tumors and to determine whether these findings enable these tumors to be classified as typical or atypical.

MATERIAL AND METHODS

We reviewed the chest CT studies performed between 1 January 2001 and 31 December 2009 in patients at our hospital diagnosed with bronchial carcinoid tumors. The sample consisted of 52 patients (23 women and 29 men) with a mean age of 47 years (range 11-77 years). The 52 cases were classified as typical or atypical on the basis of the following radiological findings: size, location, focality, type of growth, calcifications, signs secondary to bronchial obstruction, and the presence of significant lymph node enlargement or metastases. These findings were then compared with the histological findings.

RESULTS

Typical carcinoid tumors were the most prevalent (46 cases). The variables associated with atypical tumors were: male sex, advanced age at onset, and size >3cm. The accuracy of CT in classifying atypical tumors correctly increased with the number of variables indicative of atypical carcinoid tumors. A negative result for atypical nature made it possible to rule out an atypical carcinoid tumor in 95% of the cases.

CONCLUSION

CT is useful for defining and characterizing carcinoid tumors into typical or atypical, although a precise formula for differentiating between the two types remains to be defined.

Neuroendocrine neoplasms of the gut and pancreas: new insights

Neuroendocrine neoplasms arise in almost every organ of the body and are variably defined according to the site of origin. This Review focuses on neuroendocrine neoplasms of the digestive tract and pancreas. The 2010 WHO classification of tumors of the digestive system introduces grading and staging tools for neuroendocrine neoplasms. A carcinoid is now defined as a grade 1 or 2 neuroendocrine tumor and grade 3, small-cell or large-cell carcinomas are defined as neuroendocrine carcinoma. Epidemiological data show a worldwide increase in the prevalence and incidence of gastroentero-pancreatic neuroendocrine tumors in the past few decades, which is probably due to improved methods of detection of these tumors. The current diagnostic procedures and treatment options for neuroendocrine neoplasms are defined and summarized in the Review, although evidence-based data are lacking. Surgery remains the treatment mainstay and somatostatin analogues the basis for both diagnosis and therapy as the only 'theranostic' tool. Emerging compounds including chemotherapeutic agents, small molecules and biological therapies may provide new hope for patients.

Standard imaging techniques for neuroendocrine tumors

Several diagnostic imaging techniques have been used successfully for evaluating patients with neuroendocrine tumors (NETs). These techniques include computed tomography (CT), magnetic resonance imaging, positron emission tomography/CT, single-photon emission CT (SPECT), and SPECT/CT. This article reviews the various imaging methods and their respective advantages and limitations for use in different types of NETs, in particular carcinoid tumors.