Benign adrenal and suprarenal retroperitoneal schwannomas can mimic aggressive adrenal malignancies: case report and review of the literature.

The suprarenal retroperitoneum and adrenal gland is a rare site of origin for benign schwannomas which frequently present as larger and more aggressive lesions than schwannomas identified elsewhere. These tumors are often surgically excised. We present a case of an 81-year-old asymptomatic man presenting with an incidental 10 cm left suprarenal retroperitoneal mass identified on CT. The mass was indiscernible from the adrenal gland, demonstrating heterogeneous enhancement with a centrally cystic/necrotic core, and punctate calcifications. Subsequent core needle biopsy demonstrated a benign adrenal schwannoma. The lesion has been managed conservatively with imaging follow up and without complication. DISCUSSION: Our review of the literature identifies 121 reported in vivo benign adrenal and suprarenal schwannomas published to date with imaging features available for 90 cases (74%). All cases were encapsulated with the average size measuring over 6.5 cm. Fifteen percent (13/84) of reported lesions measured over 10 cm at presentation. Punctate calcification was present in 50% (26/52) of reporting cases. Nearly 50% (40/86) of cases demonstrate cystic/necrotic appearances on imaging. Despite aggressive appearances, our case demonstrates that biopsy and surveillance may represent a reasonable alternative to surgery in suboptimal surgical candidates.

Pancreatic pseudocyst-portal vein fistula with refractory hepatic pseudocyst: Two cases treated with EUS cyst-gastrostomy and review of the literature.

Background and study aims Pseudocysts are the most common pancreatic cystic lesions and they usually develop in association with pancreatitis of at least 4 weeks' duration. Extra-pancreatic pseudocysts, although reported, are relatively uncommon. Secondary liver pseudocysts are recognized within the literature, and most patients described have required percutaneous or surgical drainage due to infection or symptoms. The mechanism of hepatic pseudocyst formation is not entirely clear but it is postulated that this phenomenon may occur through pseudocyst-portal vein fistulization. We describe two cases of patients presenting with pancreatic pseudocysts invading the portal venous system with embolization of pancreatic fluid to the liver and subsequent hepatic pseudocyst formation. Interestingly, liver pseudocyst resolution was incomplete with antibiotics and percutaneous drainage alone, and only occurred following endoscopic ultrasonography-guided pancreatic cyst-gastrostomy and metal stent insertion. We have reviewed the current literature on the diagnosis and management of pseudocyst-portal vein fistula formation and we believe that our cases represent the first published within the literature to describe this treatment approach.

The utility of thyroid ultrasonography in the management of thyroid nodules.

BACKGROUND: Ultrasonography for thyroid nodules is one of the most common imaging tests performed in the general population. Details from ultrasound reports guide biopsies and surgery. This study quantifies the completeness of these reports based on Thyroid Imaging and Reporting System (TI-RADS) criteria and considers their utility in predicting malignant disease. METHODS: We retrospectively reviewed ultrasound reports for 329 thyroidectomy patients and extracted data elements using the TI-RADS criteria: nodule size, echogenicity, margins, vascularity, solid/cystic composition and the presence or absence of microcalcifications and the halo sign. We assessed the reports to determine whether individual or multiple criteria were associated with malignancy. RESULTS: More than 97% of reports document nodule size; however, more than 90% of the reports noted only 3 or fewer of the 6 remaining TI-RADS criteria. The presence of microcalcifications was the most sensitive marker of malignancy (> 90%), whereas the documentation of irregular margins was the most specific indicator of malignancy (88%). Overall it was clear that microcalcifications, hypoechogenicity, irregular margins and solid nodules were significantly more likely to be found in malignant neoplasms; their absence predicted benign disease. Because so few reports consistently documented all criteria, the overall ability of thyroid ultrasonography to discriminate between lowerand higher-risk nodules is limited. CONCLUSION: Although the accuracy of thyroid ultrasonography is good, few ultrasound reports contain the necessary information, as defined by TI-RADS, to predict malignancy and guide management. When reported, microcalcifications and/or irregular margins are the best predictors of malignancy.

CONTEXTE: L'échographie des nodules thyroïdiens est l'une des épreuves d'imagerie les plus souvent effectuées dans la population générale. Les détails fournis par l'échographie guident les biopsies et la chirurgie. Cette étude quantifie l'exhaustivité des rapports d'échographie selon les critères TI-RADS (Thyroid Imaging and Reporting System) et en mesure l'utilité pour prédire les cancers. MÉTHODES: Nous avons passé en revue de façon rétrospective les rapports d'échographie de 329 patients ayant subi une thyroïdectomie et nous en avons extrait les éléments sous l'angle des critères TI-RADS : taille des nodules, échogénicité, marges, vascularité, composition solide c. kystique, présence ou absence de microcalcifications et signe du halo. Nous avons évalué les rapports afin de déterminer si certains critères individuels ou multiples pouvaient être associés au cancer. RÉSULTATS: Plus de 97 % des rapports mentionnent la taille des nodules; mais, plus de 90 % des rapports ne font état que de 3 critères ou moins sur les 6 autres critères TI-RADS. La présence de microcalcifications a été le marqueur tumoral le plus sensible (> 90 %), tandis que la présence de marges irrégulières a été le marqueur tumoral le plus spécifique (88 %). Dans l'ensemble, les microcalcifications, l'hypoéchogénicité, les marges irrégulières et les nodules solides ont sans contredit été significativement plus susceptibles d'être observés en présence de malignité; et en revanche, leur absence permettait de prédire une maladie bénigne. Étant donné que si peu de rapports ont documenté avec constance tous les critères, la capacité globale de l'échographie de la thyroïde à distinguer entre nodules de risque faible et élevé est limitée. CONCLUSION: Même si la précision de l'échographie thyroïdienne est bonne, peu de rapports d'échographie renferment les renseignements nécessaires, selon les critères TI-RADS, pour prédire un cancer et orienter sa prise en charge. Lorsqu'elles sont signalées, les microcalcifications ou les marges irrégulières sont les meilleurs prédicteurs de cancer.

Insulinoma or non-insulinoma pancreatogenous hypoglycemia? A diagnostic dilemma.

Insulinoma is the most common cause of endogenous hyperinsulinemic hypoglycemia in adults. An alternate etiology, non-insulinoma pancreatogenous hypoglycemia (NIPH), is rare. Clinically, NIPH is characterized by postprandial hyperinsulinemic hypoglycemia, negative 72-h fasts, negative preoperative localization studies for insulinoma and positive selective arterial calcium infusion tests. Histologically, diffuse islet hyperplasia with increased number and size of islet cells is present and confirms the diagnosis. Differentiating NIPH from occult insulinoma preoperatively is challenging. Partial pancreatectomy is the procedure of choice; however, recurrence of symptoms, although less debilitating, occurs commonly. Medical management with diazoxide, verapamil and octreotide can be used for persistent symptoms. Ultimately, near-total or total pancreatectomy may be necessary. We report a case of a 67-year-old male with hypoglycemia in whom preoperative workup, including computerized tomography abdomen, suggested insulinoma, but whose final diagnosis on pathology was NIPH instead.

The value of "liver windows" settings in the detection of small renal cell carcinomas on unenhanced computed tomography.

OBJECTIVE: To assess if "liver window" settings improve the conspicuity of small renal cell carcinomas (RCC). METHODS: Patients were analysed from our institution's pathology-confirmed RCC database that included the following: (1) stage T1a RCCs, (2) an unenhanced computed tomography (CT) abdomen performed ≤ 6 months before histologic diagnosis, and (3) age ≥ 17 years. Patients with multiple tumours, prior nephrectomy, von Hippel-Lindau disease, and polycystic kidney disease were excluded. The unenhanced CT was analysed, and the tumour locations were confirmed by using corresponding contrast-enhanced CT or magnetic resonance imaging studies. Representative single-slice axial, coronal, and sagittal unenhanced CT images were acquired in "soft tissue windows" (width, 400 Hounsfield unit (HU); level, 40 HU) and liver windows (width, 150 HU; level, 88 HU). In addition, single-slice axial, coronal, and sagittal unenhanced CT images of nontumourous renal tissue (obtained from the same cases) were acquired in soft tissue windows and liver windows. These data sets were randomized, unpaired, and were presented independently to 3 blinded radiologists for analysis. The presence or absence of suspicious findings for tumour was scored on a 5-point confidence scale. RESULTS: Eighty-three of 415 patients met the study criteria. Receiver operating characteristics (ROC) analysis, t test analysis, and kappa analysis were used. ROC analysis showed statistically superior diagnostic performance for liver windows compared with soft tissue windows (area under the curve of 0.923 vs 0.879; P = .0002). Kappa statistics showed "good" vs "moderate" agreement between readers for liver windows compared with soft tissue windows. CONCLUSION: Use of liver windows settings improves the detection of small RCCs on the unenhanced CT.

Out of Africa and into an ice age: on the role of global climate change in the late Pleistocene migration of early modern humans out of Africa.

The results from two climate model simulations are used to explore the relationship between North Atlantic sea surface temperatures and the development of African aridity around 100,000 years ago. Through the use of illustrative simulations with an Earth System Climate Model, it is shown that freshwater fluxes associated with ice sheet surges into the North Atlantic, known as Heinrich events, lead to the southward shift of the intertropical convergence zone over Africa. This, combined with the overall increased aridity in the cooler mean climate, leads to substantial changes in simulated African vegetation cover, particularly in the Sahel. We suggest that Heinrich events, which occurred episodically throughout the last glacial cycle, led to abrupt changes in climate that may have rendered large parts of North, East, and West Africa unsuitable for hominin occupation, thus compelling early Homo sapiens to migrate out of Africa.