Radiologic anatomy of the superior mesenteric vein and branching patterns of the first jejunal trunk: evaluation using multi-detector row CT venography

The purpose of this study was to describe radiologic anatomy of the superior mesenteric vein (SMV) and to evaluate branching patterns of the first jejunal trunk on axial CT images and multi-detector row CT (MDCT) venography in adults. Two hundred and twenty consecutive patients who underwent abdominal CT examinations were enrolled in this study. Appearance of the SMV, branching patterns of the first jejunal trunk, and drainage site of the inferior mesenteric vein (IMV) were assessed on axial CT images and MDCT venography. The SMV and first jejunal trunk were identified in all patients. A single trunk of the SMV was present in 95% (210/220) and absent in 5% (10/220). First jejunal trunk crossed dorsal to the superior mesenteric artery (SMA) towards the left abdomen in 64% (141/220) and first jejunal trunk crossed ventral to the SMA in 19% (41/220). First jejunal trunk crossed dorsal to the SMA and abruptly turned towards the right abdomen in 17% (38/220). Among these 38 patients, biliary-enteric bypass surgery (n = 9) and large hematoma in left abdomen (n = 1) were present. The IMV was identified in 213 patients and was observed to drain into splenic vein in 112 patients (53%), SMV in 67 (31%), splenoportal confluence in 26 (12%), and first jejunal trunk in 8 (4%). In conclusion, the first jejunal trunk, abruptly turning toward the right abdomen, may be an anatomic variant or indirect finding of biliary-enteric anastomosis. The IMV may drain into the first jejunal trunk as well as splenic vein, splenoportal confluence, and SMV.     

The first experience of robot assisted spleen-preserving laparoscopic distal pancreatectomy in Korea

Spleen-preservation has recently been emphasized in benign and borderline malignant pancreatic diseases requiring distal pancreatectomy. Reports to suggest that laparoscopic distal pancreatectomy is feasible and safe have been increasingly published. Robotic surgical system has been introduced and is expected to provide unique advantages in laparoscopic surgery. However, robot-assisted pancreatic surgery has not yet been performed by many surgeons. A 45-year-old female patient with abdominal discomfort was found to have pancreatic cyst in the body of the pancreas. Mucinous cystic tumor of the pancreas was the most favourable preoperative diagnosis. She underwent spleen-preserving laparoscopic distal pancreatectomy by using da Vinci surgical robot system. Splenic artery and vein were so tightly adherent to the pancreatic cyst that segmental resection of splenic vessels was required. Postoperative course was uneventful. She was able to come home in 5 days after surgery. Postoperative follow up color doppler ultrasound scan, taken on 2 weeks after surgery, showed minimal fluid collection around surgical field and no evidence of splenic infarction with good preservation of splenic perfusion. Robot-assisted spleen preserving distal pancreatectomy is thought to be feasible and safe. Several unique advantages of robotic system are expected to enhance safer and more precise surgical performance in near future. More experiences are mandatory to confirm real benefit of robot surgery in pancreatic disease.     

Relationship between diseases of the pancreas and hyperplasia of Brunner's glands

Summary Examination of 105 duodeno-pancreatectomy specimens showed that 75.7% of the cases of chronic pancreatitis (n = 74) manifested diffuse hyperplasia of Brunner's glands. In pancreatitis involving part of the pancreas in the presence of ducts of the embryonic type (n = 6), in segmental pancreatitis (n = 16), and in pancreatic cancer (n = 23), no significant difference in the thickness of the layer of Brunner's glands was found as compared with normal specimens.There was no statistically significant correlation between the degree of hyperplasia of Brunner's glands and the degree of scarring of the exocrine pancreatic parenchyma. Nor was there any correlation between existence and extent of scarring of the duodenal wall, inflammatory infiltration of the duodenal mucosa, duration of disease, consumption of alcohol and history of gall stones and ulcers in patients with and without hyperplasia of Brunner's glands. Diffuse hyperplasia of the duodenal glands is probably an adaptive reaction to the exocrine insufficiency of the pancreas or the changes in gastric function (hyperacidity, accelerated emptying of the stomach) caused by chronic pancreatitis. A fact which supports this statement is that the inhibitor hormone urogastrone — an inhibitor of gastric acid secretion — is formed in Brunner's glands. The question is also discussed whether chronic pancreatitis and hyperplasia of Brunner's glands might not also develop simultaneously in the presence of disturbances of the gastrointestinal hormones, themselves either primary or due to alcohol consumption.     

Dorsal pancreas agenesis: computed tomography appearance with three-dimensional volume rendering reconstruction

We report a case of a very rare congenital variant consisting in a dorsal (or left) pancreas agenesis due to the lack of development of the dorsal embryonic bud of the gland. This variant is characterized using helical computed tomography (CT). Three-dimensional (3D) computed tomography reconstruction, especially using the volume rendering technique, is very helpful for assessing this entity, which it is important to recognize due to its potential clinical implication (diabetes mellitus). Associated variants of abdominal vessels were also clearly seen in our patient with this technique, including a hepatomesenteric trunk and left retro-aortic renal vein.     

Malignant solid pseudopapillary tumor of pancreas causing sinistral portal hypertension

Solid pseudopapillary tumor (SPT) of the pancreas is a rare benign or low-grade malignant epithelial tumor that occurs mainly in young females in second to fourth decades of life. Pathologic and imaging findings include a well-defined, encapsulated pancreatic mass with cystic and solid components with evidence of hemorrhage. We report a 23-year-old female who presented with upper abdominal pain of long duration and epigastric mass on palpation. Multidetector-row CT (MDCT) demonstrated a large well-defined heterogeneous attenuation mass, containing hyperdense areas of hemorrhage mixed with solid enhancing and cystic non-enhancing areas, arising from the pancreatic body and tail. Splenic vein thrombosis was present with dilated splenoportal collateral vessels between splenic hilum and portal/superior mesenteric veins, with dilated vessels seen in the gastric wall, with patent portal vein, compatible with sinistral portal hypertension. Typical imaging features and age and sex of the patient suggested a diagnosis of SPT of pancreas complicated by segmental portal hypertension due to splenic vein thrombosis. Histopathology of the biopsy material was confirmatory.     

Accessory spleen presenting as a mass in the tail of the pancreas

In this case report, we describe an accessory spleen that presented as a mass in the tail of the pancreas and mimicked a neoplasm. Intrapancreatic accessory spleen have a relatively high prevalence and can be mistaken for tumors. We present a case of intrapancreatic accessory spleen in a 40-year-old man, which was discovered incidentally during a workup for an aortic dissection. Computerized axial tomography and magnetic resonance imaging scans demonstrated a hypervascular mass in the tail of the pancreas. The clinical and radiological differential diagnosis included pancreatic mucinous cystic neoplasm, pancreatic endocrine neoplasm, solid pseudopapillary tumor, ductal adenocarcinoma, and metastasis. After a distal pancreatectomy was completed, microscopic examination revealed heterotopic splenic tissue.     

The structure of the Graafian follicle as revealed by microdissection

Summary A study of the developing spleen in thirty-three embryos of the Gecko, Gymnodactylus kotschyi, revealed the fact that four phases occurred. In thefirst phase the spleen anlage appears as a plate of cells on the peritoneal surface of the dorsal mesentery, just above the primordial stomach. Thesecond phase shows the spleen as a brick-shaped protuberance in which the first capillaries (believed to be arterial) appear. The blood drains through the dorsal pancreas to enter the ductus venosus. Thethird phase shows the spleen as an oval with a more extensive system of capillaries which still seem to be arterial in nature. The blood still drains into the dorsal pancreas, thence to the ductus venosus. Thefourth phase persists to the time of hatching and reveals a change in the circulatory system of the spleen. The capillaries within the spleen are of two sizes. Those closest to the splenic artery are smaller in diameter than those which lead to the splenic vein. The former seem to be arterial and the latter venous in type. The splenic vein enters the ductus venosus direct. The intermediate pathway through the pancreas has now been dicontinued. The cells of the spleen are very small and almost entirely nuclear in the later embryonic stages.

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Zusammenfassung Eine Untersuchung über die Entwicklung der Milz von 33 Embryonen des Gecko (Gymnodactylus kotschyi) zeigt, daß der Vorgang in vier Zeitabschnitten stattfindet.In demersten Abschnitt erscheint die Anlage der Milz als eine Platte von Zellen an der peritonealen Oberfläche des dorsalen Mesenteriums, nahe über dem primordialen Magen.Während deszweiten Abschnittes erscheint die Milz in der Form einer ziegelsteinartigen Hervorragung in welcher die ersten Capillaren (wahrscheinlich arterielle Capillaren) zum Vorschein kommen. Das Blut geht durch die dorsale Pankreas und tritt in den Ductus venosus ein.Derdritte Abschnitt zeigt die Milz als ein Oval mit einem weitverzweitgten Capillarsystem, welches noch immer arteriell zu sein schcint. Das Blut nimmt denselben Weg im zweiten Abschnitt.Dervierte Abschnitt dauert bis zum Zeitpunkt des Ausschlüpfens und gibt einen Einblick in die Veränderung des Blutkreislaufs der Milz. Die Capillaren in der Milz sind von zweierlei Größe. Die Capillaren in der Nähe der Milzarterie sind kleiner als die, welche in die Vene führen. Die ersteren scheinen arteriell zu sein, während die letzteren veneus sind. Die Vene der Milz tritt direkt in den Ductus venosus ein. Der Umweg durch die Pankreas ist nun vermieden. Die Zellen der Milz sind sehr klein und bestehen in späteren embryonischen Stufen beinahe nur aus dem Zellkern.

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Course of the short gastric veins and their suitability for pancreatic islet transplantation

Experience is being gained with pancreatectomy for patients with chronic pancreatitis suffering intractable pain. Transplantation of pancreatic islets isolated from the patient's own pancreas reduces the amount of injected insulin required, and research aims to develop treatments to make such patients independent of administered insulin. Claims have been made that the uppermost short gastric vein runs directly to the upper pole of the spleen in about 90% of subjects and that infusion of pancreatic islets by this route would allow them to settle in the spleen. This study investigates these claims. The findings suggest that the short gastric veins are inappropriate as a route of islet administration. Most short gastric veins, including the most superior, drain to tributaries of the splenic vein. Short gastric veins passing to the spleen itself without extra-splenic connections to the splenic vein and its tributaries are relatively rare. Only four examples in 12 specimens were found, and only two of these were the most superior short gastric vein. The short gastric veins run in the fat of the gastrosplenic ligament and are most readily visible as they leave the stomach. In our 12 dissecting room specimens, the short gastric veins ranged in number from 3-17, and in diameter from 0.5-4.5 mm (mean = 1.7 mm; SD = 0.7 mm). The four short gastric veins that drained directly to the spleen ranged in diameter from 0.5-1 mm, significantly narrower than those draining to the splenic vein or its tributaries and small for cannulation.     

Quantitative immunocytochemical analysis of the endocrine pancreas of the Nile crocodile

Four major pancreatic hormones were immunolocalized at the light and electron microscopic levels in the pancreas of the Nile crocodile, Crocodilus niloticus. Immunogold was used for electron microscopy, and peroxidase-antiperoxidase was used for light microscopy. Somatostatin-positive D-cells and pancreatic polypeptide-containing F-cells accounted for about 60% of the immunoreactive cells in the ventral pancreas. Glucagon-positive A-cells were the least frequent cell type in the ventral pancreas, about 15%, but were the predominant cell type, about 40%, in the pancreas that was dorsal in character. An expanded population of D-cells (relative to mammals and other higher vertebrates) in association with two very different numbers of A-cells can be expected to have important consequences for the homotropic control of secretory activity of the endocrine pancreas as well as for the function of the acinar pancreas. F-cells were absent from the dorsal part of the pancreas, whereas insulin-containing B-cells were slightly more abundant in this portion of the pancreas. The regional character of the endocrine pancreas was related to the complex looping of the proximal small intestine. Without immunolabeling, only B-granules were morphognomonic in electron micrographs. The insulin-reactive B-granules were the smallest (370 nm) of the secretory granules and were followed in size by somatostatin-positive D-granules (380 nm). The pancreatic polypeptide-containing secretory granules were the largest (580 nm). Glucagon-reactive A-granules (430 nm) sometimes exhibited a protuberance or extension of secretory granule matrix and limiting membrane. Such a morphological feature has previously been associated with secretion of glucagon and the initiation of insulin secretion. Taken together these studies indicate that protuberances have a significant, but as yet undefined, role in pancreatic endocrine cells.     

Multiple lipoma in a stray donkey (first report in veterinary literature)

Lipoma is a common benign tumor of well-differentiated adipocytes, which seen in most domestic animals. A 5-year-old male stray donkey was necropsied for educational purposes in the veterinary hospital of Shahid Bahonar University of Kerman. The animal was cachectic, but normal in the other respects. At necropsy, the tumors were well-circumscribed, unencapsulated, soft white to yellow masses very similar to normal fat tissue. These masses were attached to stomach, small intestine, and pancreas. Microscopic findings indicated that the cells of the tumor were identical to those in normal fat tissue. Large vacuoles replaced the cytoplasm, with peripheralization of the nuclei. No necrosis, inflammation, dystrophic calcification, and fibrosis were seen. Based on the aforementioned macroscopic and histopathologic findings multiple lipoma was diagnosed. Based on author’s knowledge, multiple lipoma in various organs such as the stomach, intestine, and pancreas has not been reported in animals, especially in donkey. In conclusion, we report here a very rare case of multiple lipoma (lipomatosis) with no clinical signs in a stray donkey.     

Multidetector computed tomography for preoperative evaluation of vascular anatomy in living renal donors

Background  Currently, multidetector computed tomographic (MDCT) angiography has become a noninvasive alternative imaging modality to catheter renal angiography for the evaluation of renal vascular anatomy in living renal donors. In this study, we investigated the diagnostic accuracy of 16-slice MDCT in the preoperative assessment of living renal donors. Methods  Fifty-nine consecutive living renal donors (32 men, 27 women) underwent MDCT angiography followed by open donor nephrectomy. All MDCT studies were performed by using a 16-slice MDCT scanner with the same protocol consisting of arterial and nephrographic phases followed by conventional abdominal radiography. The MDCT images were assessed retrospectively for the number and branching pattern of the renal arteries and for the number and presence of major or minor variants of the renal veins. The results were compared with open surgical results. Results  The sensitivity and specificity of MDCT for the detection of anatomic variants of renal arteries including the accessory arteries (n = 9), early arterial branching (n = 7) and major renal venous anomalies including the accessory renal veins (n = 3), late venous confluence (n = 4), circumaortic (n = 2) or retroaortic (n = 3) left renal veins were 100%. However, the sensitivity for identification of minor venous variants was 79%. All of three ureteral duplications were correctly identified at excretory phase conventional abdominal radiography. Conclusion  Sixteen-slice MDCT is highly accurate for the identification of anatomic variants of renal arteries and veins. Dual-phase MDCT angiography including arterial and nephrographic phases followed by conventional abdominal radiography enables complete assessment of renal donors without significant increase of radiation dose. However, the evaluation of minor venous variants may be problematic because of their small diameters and poor opacification.     

Endocrine cells in intraductal papillary-mucinous neoplasms of the pancreas

 The endocrine cells in intraductal papillary-mucinous neoplasms (IPN) of the pancreas have rarely been investigated. In the normal pancreatic ducts of normal pancreases (n=5) there were a few endocrine cells: argyrophil in 5 (100%), chromogranin A in (100%), pancreatic polypeptide (PP) in 3 (60%), and insulin in 7 (20%). These endocrine cells were scattered, and located in the basal portions of pancreatic ducts. In IPN of the pancreas (n=9), there were many endocrine cells: argyrophil in 7 (78%), argentaffin in 8 (89%), chromogranin A in 8 (89%), PP in 7 (78%), serotonin in 7 (78%), insulin in 4 (44%), and gastrin in 5 (56%). In invasive ductal adenocarcinoma of the pancreas (n=6), many endocrine cells were also detected: argyrophil cells in (67%), chromogranin A in 3 (50%), insulin in 3 (50%), glucagon in 4 (67%), and somatostatin in 3 (50%). In positive cases, endocrine cells were situated under or among the neoplastic cells and the proportion of endocrine cells in IPN was less than 5% of the total neoplastic cell population. These data show that normal pancreatic ducts contain endocrine cells and that IPN frequently contain argyrophil, argentaffin, chromogranin A, and hormone-containing endocrine cells. These data also suggest that endocrine differentiation occurs during neoplastic transformation and progression of IPN of the pancreas. Received: 3 December 1996 / Accepted: 25 February 1997     

Neuronally mediated anion secretion induced by short-chain fatty acids in the rat distal small intestine

The short-chain fatty acids acetate, propionate and butyrate induced a concentration-dependent increase of short-circuit current (I_sc) in the rat distal small intestine in vitro. They were ineffective in the proximal small intestine. The increase of I_sc in the distal small intestine was dependent on the presence of Cl^- and HCO^-₃ ions. It was blocked by the inhibitor of the Na⁺-K⁺-Cl^--cotransporter, bumetanide, and by the Cl^- channel blocker, 5-nitro-2-(3-phenylpropylamino)-benzoate, indicating that short-chain fatty acids evoke an anion secretion. The secretion induced by propionate was blocked by the neurotoxin, tetrodotoxin, and inhibited by the muscarinic antagonists, atropine. In contrast, indomethacin, a cyclooxygenase inhibitor, or nordihydroguaiaretic acid, a lipoxygenase inhibitor, were ineffective. These results indicate that short-chain fatty acids stimulate chemosensitive neurones in the rat small intestine in a region-specific manner, which induce anion secretion by the release of mainly acetylcholine.     

Clinical Comparison of Distal Pancreatectomy with or without Splenectomy

The spleen may be preserved during distal pancreatectomy (DP) for benign disease. The aim of this study was to compare the perioperative and postoperative courses of patients with conventional DP and spleen-preserving distal pancreatectomy (SPDP) for benign lesions or tumors with low-grade malignant potential occurred at the body or tail of the pancreas. A retrospective analysis was performed for the hospital records of all the patients undergoing DP and SPDP between January 1995 and April 2006. One-hundred forty-three patients underwent DP and 37 patients underwent SPDP. There were no significant differences in age, sex, indications of operation, estimated blood loss, operative time, and postoperative hospital stay between the two groups. Pancreatic fistula occurred in 21 (13.3%) patients following DP and in 3 (8.1%) following SPDP without a significant difference (p=0.081). Portal vein thrombosis occurred in 4 patients after DP. Splenic infarction occurred in one patient after SPDP. Overwhelming postosplenectomy infection was observed in one patient after DP. SPDP can be achieved with no increase in complication rate, operative time, or length of postoperative hospitalization as compared to conventional DP. Additionally, it has the advantage of reducing the risk of overwhelming postsplenectomy infection and postoperative venous thrombosis.     

Loss of GATA4 causes ectopic pancreas in the stomach

Pancreatic heterotopia is defined as pancreatic tissue outside its normal location in the body and anatomically separated from the pancreas. In this work we have analyzed the stomach glandular epithelium of Gata4 ^flox/flox; Pdx1-Cre mice (Gata4KO mice). We found that Gata4KO glandular epithelium displays an atypical morphology similar to the cornified squamous epithelium and exhibits upregulation of forestomach markers. The developing gastric units fail to form properly, and the glandular epithelial cells do not express markers of gastric gland in the absence of GATA4. Of interest, the developing glands of the Gata4KO stomach express pancreatic cell markers. Furthermore, a mass of pancreatic tissue located in the subserosa of the Gata4KO stomach is observed at adult stages. Heterotopic pancreas found in Gata4-deficient mice contains all three pancreatic cell lineages: ductal, acinar, and endocrine. Moreover, Gata4 expression is downregulated in ectopic pancreatic tissue of some human biopsy samples. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Pancreatographic investigation of the pancreatic duct system

Background Embryologically, the pancreatic duct system develops by the fusion between the dorsal and ventral pancreatic bud ducts. It has been suggested that the proximal part of the main dorsal pancreatic duct partially regresses to form the accessory pancreatic duct (APD). Aim of this study was to clarify the anatomy of the pancreatic duct system of the head of the pancreas and investigate the embryology of the normal pancreatic duct system. Methods We reviewed endoscopic retrograde pancreatography of normal pancreatic heads (n = 256) and pancreas divisum (n = 36), focusing on long inferior branches arising from the APD and the main pancreatic duct (MPD). The accessory pancreatograms were divided into two patterns of course and shape, the long type (171 cases) and the short type (85 cases) according to the length of the MPD from the orifice to the junction with the APD. The long-type APD formed a straight line and joined the MPD at the neck portion of the pancreas. The short-type APD joined the MPD near its first inferior branch. Results The shape of the long-type APD was quite similar to that of the dorsal pancreatic duct of pancreas divisum. The short-type APD was less likely to have a long inferior branch arising from the APD. The length of the APD from the orifice to the first long inferior branch was similar in the long-type APD (19.4 ± 4.0 mm) and in the short-type APD (18.8 ± 4.2 mm). The first long inferior branch from the long-type APD passed though the MPD near the origin of the inferior branch from the MPD, whereas the short-type APD joined the MPD near its inferior branch. Conclusions There are two types of APD. The long-type APD was quite similar to the shape of the dorsal pancreatic duct of pancreas divisum, and seems to represent a continuation of the main duct of the dorsal pancreatic bud. The short-type APD was less likely to have a long inferior branch, and seems to be formed by the most proximal part of the main duct of the dorsal pancreatic bud and its long inferior branch.     

Lipoteichoic acid may affect the pathogenesis of PBC-like bile duct damage and might be involved in systemic multifocal epithelial inflammations in chronic colitis-harboring TCRα−/−×AIM−/− mice

Background: Chronic colitis-harboring TCRα^{? / ?} × AIM^{? / ?} mice showed PBC-like bile duct damage in the liver. Bacterial infection is one of the candidates for the pathogenesis of PBC. We demonstrated that the bacterial cell wall component lipotheicoic acid (LTA) was detected at sites of inflammation around damaged bile ducts in PBC patients. The aim of this study was to investigate the pathophysiology of the liver and other organs in TCRα^{? / ?} × AIM^{? / ?} mice.

Methods: Thirteen female TCRα^{? / ?} × AIM^{? / ?} mice were sacrificed at 24 weeks of age. The liver, stomach, small intestine, colon, pancreas, kidney and spleen were studied for pathological examination. Using anti-LTA antibody as the primary antibody, an immunohistochemical study was carried out.

Results: In the liver, LTA was mainly detected in the portal area with inflammation, and some of the cytoplasm of hepatocytes. Inflammations were also observed in the stomach, intestine, pancreas and kidney. Throughout the gastrointestinal tract, from the stomach to the colon, LTA was detected in the epithelium at sites of inflammation. Furthermore, LTA was detected around both pancreatic ducts with inflammation and distal renal tubules with inflammation.

Conclusions: The development of inflammations in the liver as well as extensive organs, strongly suggests a close relationship between bile duct damage and systemic multifocal epithelial inflammations, perhaps involving bacterial LTA, in TCRα^{? / ?} × AIM^{? / ?} mice.     

Appl1 is essential for the survival of Xenopus pancreas,duodenum, and stomach progenitor cells

An understanding of the molecular mechanisms governing the survival of organ progenitor cells in vivo is crucial for in vitro tissue regeneration. Here, we have found that Xenopus appl1 and akt2 share a similar embryonic expression pattern, showing characteristic expression in the central nervous system as well as in the pancreas and part of the stomach/duodenum (SD) at tadpole stages of development. Specific knockdown of appl1 in endoderm or inhibition of akt activity did not affect the formation of endodermal organ primordia at tail bud stages of development, but led to a gut‐coiling defect, strong apoptosis in endodermal organs, and pancreas and SD hypoplasia or even aplasia at tadpole stages of development. Furthermore, appl1 is required for akt phosphorylation and akt2 in turn can rescue appl1 knockdown phenotypes. Together, our data suggest that appl1‐akt signaling is specifically required for the survival of pancreas and SD progenitor cells in Xenopus laevis embryos. Developmental Dynamics 239:2198–2207, 2010. © 2010 Wiley‐Liss, Inc.     

Hepatocellular carcinoma arising from ectopic liver tissue in the pancreas

Liver tissue ectopia is a well-documented phenomenon. Rarely, hepatocellular carcinoma arises from the ectopic liver tissue. In this paper, we report a case of a primary, well-differentiated hepatocellular carcinoma arising from ectopic liver tissue in the pancreas. The patient is a 58-year-old Hispanic man with no history of underlying liver diseases or chronic pancreatic diseases. Patient presented with a several days history of abdominal pain with radiation to his right upper quadrant. Imaging study revealed a 3.7 × 3.3-cm mass in the distal pancreas. No other lesions were identified. Preoperative fine needle aspiration revealed blood and atypical hepatocytes. The patient underwent distal pancreatectomy and splenectomy for suspected neuroendocrine tumor. Gross examination revealed a well-circumscribed 3.3-cm, beige-tan, pseudolobulated tumor with focal areas of hyperpigmentation. A microscopic examination revealed hepatoid cells arranged in a trabecular pattern with focal bile pigment. Immunohistochemistry study showed that the tumor cells were reactive with hepatocyte antigen (Hep par 1), alpha-1 antitrypsin, but negative for synaptophysin and chromogranin. Immunostain for polyclonal carcinoembryonic antigen showed a typical bile canalicular pattern. These results support that this tumor in the pancreas is hepatocellular carcinoma, most likely arising from ectopic liver tissue within the pancreas.     

Nature of optokinetic response and zonal organization of climbing fiber afferents in the vestibulocerebellum of the pigmented rabbit

Summary In pigmented rabbits anesthetized with N₂O (70%) and halothane (2–4%), Purkinje cells were extracellularly recorded in the nodulus. Large field (60°×60°) optokinetic stimulation (OKS) with constant velocity was delivered to either the ipsi- or contralateral eye, and the direction and velocity selectivities of complex spike responses were examined. To ipsilateral OKS (n = 181), the preferred direction was forward (F, n = 72), upward (U, n = 38) or downward (D, n = 10), while the remaining cells (n = 61) showed no response (N). To contralateral OKS (n = 117), the preferred direction was backward (B, n = 22), upward (U, n = 7) or downward (D, n = 22), while the rest (n = 66) showed N. Cells tested with both eyes (n = 95) fell into 8 categories based on the preferred direction to ipsi- and contralateral OKS: (1) ipsi-F and contra-B (F/B type, n = 20), (2) ipsi-F but contra-N (F/N type, n = 12), (3) ipsi-U and contra-D (U/D type, n = 15), (4) ipsi-U but contra-N (U/N type, n = 13), (5) ipsi-N but contra-D (N/D type, n = 1), (6) ipsi-D but contra-N (D/N type, n = 5), (7) ipsi-N but contra-U (N/U type, n = 6), and (8) N to both eyes (N/N type, n = 23). The optimum velocity was in the range 0.1–2.0°/s for all cells responsive to OKS. In the ventral lamella, four medio-laterally aligned zones were demonstrated. In the most medial zone (0–0.5 mm from the midline), the majority of cells showed ipsi-N or contra-N responses. In the second zone (0.5–1.5 mm), most cells preferred ipsi-F or contra-B directions. In the third zone (1.5–2.5 mm), most cells preferred ipsi-U or contra-D directions. In the most lateral zone (2.5–3.5 mm), most cells preferred ipsi-F or contra-B directions. In the dorsal lamella, a longitudinal zone characterized with cells preferring ipsi-U or contra-D directions was found about 1.5–2.5 mm from the midline. This zone seemed to be the continuation of the third zone in the ventral lamella. Cells preferring ipsi-D or contra-U directions were scattered in the medial half of both the dorsal and ventral lamellae. Most cells responsive to electrical stimulation of the contralateral optic tract (OT) preferred the ipsi-F direction and were localized in the second and the most lateral zones of the ventral lamella. As for cells activated by a climbing fiber with a branching axon to the flocculus, no characteristic feature was found in terms of the preferred direction to OKS, except that none of the cells preferring ipsi-D or contra-U directions were activated by such branching climbing fibers. The results indicate that the nodulus consists of at least four functionally distinct zones in terms of direction selectivity of visual climbing fiber afferents.