A discrepant finding between magnetic resonance imaging and other imaging modalities suggests a microcystic serous cystadenoma of the pancreas

Summary Background. Serous cystadenoma of the pancreas is generally considered as having no malignant potential. Thus, of clinical importance is a differential diagnosis of this neoplasm from other solid tumors that are often malignant. Results. We report a case of microcystic serous cystadenoma of the pancreas. Abdominal ultrasonography, computed tomography, and endoscopic ultrasonography showed a solid mass in the body of the pancreas with a diameter of 15 mm, but magnetic resonance imaging revealed it as a unilocular cystic lesion. Histological examinations on the surgically resected tissue specimen showed a honeycombed tumor with innumerable tiny cysts appearing grossly as a solid mass. The discrepant finding between magnetic resonance imaging and other imaging modalities observed in this case is suggestive of and might be specific to microcystic serous cystadenoma of the pancreas. Conclusions. Magnetic resonance imaging is a mandatory modality to identify pancreatic serous cystadenoma that contains no visible cystic compartments on computed tomography and ultrasonography.     

A discrepant finding between magnetic resonance imaging and other imaging modalities suggests a microcystic serous cystadenoma of the pancreas.

BACKGROUND: Serous cystadenoma of the pancreas is generally considered as having no malignant potential. Thus, of clinical importance is a differential diagnosis of this neoplasm from other solid tumors that are often malignant. RESULTS: We report a case of microcystic serous cystadenoma of the pancreas. Abdominal ultrasonography, computed tomography, and endoscopic ultrasonography showed a solid mass in the body of the pancreas with a diameter of 15 mm, but magnetic resonance imaging revealed it as a unilocular cystic lesion. Histological examinations on the surgically resected tissue specimen showed a honeycombed tumor with innumerable tiny cysts appearing grossly as a solid mass. The discrepant finding between magnetic resonance imaging and other imaging modalities observed in this case is suggestive of and might be specific to microcystic serous cystadenoma of the pancreas. CONCLUSIONS: Magnetic resonance imaging is a mandatory modality to identify pancreatic serous cystadenoma that contains no visible cystic compartments on computed tomography and ultrasonography.     

Intracranial findings in progressive facial hemiatrophy.

There have been infrequent reports of cerebral lesions associated with progressive facial hemiatrophy. Six children with progressive facial hemiatrophy were evaluated. Four were referred for evaluation of neurological deficits: 2 with seizures, one with left hemiparesis and one with learning problems. The remaining 2 patients had only facial hemiatrophy. Cranial computed tomography (CT) in 5 patients revealed the bony and soft tissue defects, but cerebral calcifications were seen in only 3 patients. Cranial magnetic resonance imaging (MRI) demonstrated areas of increased signal in the ipsilateral white matter on T2 weighted images in all 5 patients with upper facial atrophy. Ipsilateral cerebral lesions with progressive facial hemiatrophy may be more common than once believed. MRI sometimes reveals abnormalities of the white matter even in patients without neurologic symptoms, and may be more sensitive than CT in the diagnostic evaluation of patients with progressive facial hemiatrophy.     

Granular cell tumor of the pancreas diagnosed by endoscopic ultrasound-guided fine-needle aspiration

A 68-year-old woman was referred to our hospital for the treatment of bile duct stone, pancreatic tumor, and pancreatic cysts. First, bile duct stone was removed using endoscopic retrograde cholangiopancreatography. By abdominal contrast-enhanced computed tomography, a 12-mm diameter tumor was found in the pancreatic body. The tumor was isodense compared with the surrounding pancreatic parenchyma in the non-contrast phase and poorly enhanced in the arterial phase; it exhibited gradual enhancement from the portal vein phase to the late phase. Numerous pancreatic cysts were also observed by contrast-enhanced computed tomography. By magnetic resonance imaging, the tumor was hypointense in T1-weighted images, isointense in T2-weighted images, and hyperintense in diffusion-weighted images. By magnetic resonance cholangiopancreatography, the main pancreatic duct was not dilated, and pancreatic cysts communicated with the main pancreatic duct. The pancreatic cysts were diagnosed as branch-type intraductal papillary mucinous neoplasm. Histopathologic assessment of the specimens obtained by endoscopic ultrasound-guided fine-needle aspiration revealed the tumor as benign pancreatic granular cell tumor. The patient was followed up without surgical resection. On contrast-enhanced computed tomography at 6 months after admission, the tumor did not show any changes in diameter or characteristics.     

Age-Related Incidence of Pineal Gland Calcification in Children: A Roentgenological Study of 1,044 Skull Films and a Review of the Literature

Anterior-posterior and lateral skull roentgenograms of 1,044 children aged 0-18 yr were examined for pineal gland calcification. Eighty children with pineal calcification were identified. Cranial computed tomograms (CCT) existing for half of the 80 cases provided confirmation. In contrast to existing reports on pineal calcification in the first decade of life, we found a significant percentage of "physiological" calcification even between 0 and 6 yr of age (range 2.9-4.2%). Contrary to current opinion we were not able to detect any signs of pineal gland tumors in these cases. We were able to confirm other reports which note a steep rise of the incidence of pineal calcification during the second decade of life.     

HPLC validation of a circadian melatonin rhythm in the pineal gland of inbred mice

Abstract: Production of melatonin in the pineal gland of inbred mice such as C57B1/6J, B ALB/c and AKR strains is still a matter of debate. In previous studies, we and other authors showed that these strains of inbred mice have a clear-cut circadian rhythm of serum melatonin and urinary 6-hydroxy-melatonin-sulphate. In contrast, other groups claimed these mice are unable to synthesize melatonin. These studies were based on RIA measurements and/or estimates of N-acetyltransferase (NAT) and hydroxyindole-O-methyltransferase (HIOMT) activities. In the present study we validate the presence of melatonin in the pineal gland of C57B1/6, BALB/c, and AKR mice by HPLC determinations. We found a short-term melatonin peak in the middle of the dark period with a pattern which mirrors that found previously in the serum. The possibility remains, although it seems unlikely, that the pineal melatonin rhythm measured here represents melatonin produced elsewhere which then was subsequently taken up by the pineal gland.     

Evidence for differential photic regulation of pineal melatonin synthesis in teleosts

The aim of this study was to compare the circadian control of melatonin production in teleosts. To do so, the effects of ophthalmectomy on circulating melatonin rhythms were studied along with ex vivo pineal culture in six different teleosts. Results strongly suggested that the circadian control of melatonin production could have dramatically changed with at least three different systems being present in teleosts when one considers the photic regulation of pineal melatonin production. First, salmonids presented a decentralized system in which the pineal gland responds directly to light independently of the eyes. Then, in seabass and cod both the eyes and the pineal gland are required to sustain full night-time melatonin production. Finally, a third type of circadian control of melatonin production is proposed in tilapia and catfish in which the pineal gland would not be light sensitive (or only slightly) and required the eyes to perceive light and inhibit melatonin synthesis. Further studies (anatomical, ultrastructural, retinal projections) are needed to confirm these results. Ex vivo experiments indirectly confirmed these results, as while the pineal gland responded normally to day-night rhythms in salmonids, seabass and cod, only very low levels were obtained at night in tilapia and no melatonin could be measured from isolated pineal glands in catfish. Together, these findings suggest that mechanisms involved in the perception of light and the transduction of this signal through the circadian axis has changed in teleosts possibly as a reflection of the photic environment in which they have evolved in.     

Venous hemangioma arising from the diaphragm: a case report of computed tomography and magnetic resonance imaging findings

We report a rare case of diaphragmatic hemangioma with computed tomography and magnetic resonance imaging findings. A routine chest radiograph in a 75-year-old woman revealed a nodular opacity in the right lower lung field. Multidetector-row computed tomography revealed a well-circumscribed nodule arising from the diaphragm or pleura. Dynamic magnetic resonance imaging of the nodule showed a pattern of gradually increasing signal intensity. On the basis of the intraoperative and histopathologic findings, venous hemangioma arising from the diaphragm was diagnosed.     

Cloning,localization and functional properties of a cGMP-gated channel in photoreceptor cells from fish pineal gland

The perception of photic information and its translation into a rhythmic melatonin signal differ considerably among vertebrates. In the fish pineal gland, melatonin biosynthesis is controlled directly by the natural light/dark cycle. There are indications that the mechanisms of phototransduction are similar in the retinal and pineal photoreceptor cells. Here we report the molecular cloning of a novel ionic cyclic guanosine monophosphate (cGMP)-gated channel from trout pineal photoreceptors. The deduced amino acid sequence exhibits a high sequence homology to cyclic nucleotide-gated-3 (CNG) channels from retinal cones. In situ hybridization with sections of trout pineal gland revealed the expression of CNG channel in photoreceptor cells of the pineal organ. Electrophysiological studies by means of patch-clamp technique indicated that the native channel in photoreceptor cells and the expressed channel in a human cell line (HEK 293 cells) have properties similar to those of cone-CNG (cCNG)-3 channels. They are activated by cGMP, insensitive to cyclic adenosine monophosphate (cAMP) and blocked by intracellular Mg2+ ions at positive voltage values. They have a single-channel conductance close to 42 pS in negative voltage range. In transfected HEK cells loaded with the calcium indicator dye Fura 2, direct activation of CNG channels by 8-Br-cGMP increased fluorescence. The signal was blocked by the addition of Mg2+ ions. From these results, it is suggested that the pineal cyclic nucleotide-gated channel is a good candidate for mediating calcium entry into the pineal photoreceptors. It is most probably a key element in the signalling pathways that control the rhythmic production of melatonin.     

Alcohol and the human brain: a systematic review of different neuroimaging methods

Background: Imaging techniques have been in widespread use in the scientific community for more than 3 decades. They facilitate noninvasive, in vivo studies of the human brain in both healthy and diseased persons. These brain‐imaging techniques have contributed significantly to our understanding of the effects of alcohol abuse and dependence on structural and functional changes in the human brain. A systematic review summarizing these contributions has not previously been conducted, and this is the goal of the current paper. Methods: The databases PubMed, PsycINFO, and PSYNDEX were searched using central key words. Fulfilling the inclusion criteria were 140 functional and structural imaging studies, together comprising data from more than 7,000 patients and controls. The structural imaging techniques we considered were cranial computerized tomography and various magnetic resonance imaging–based techniques, including voxel‐based morphometry, deformation‐based morphometry, diffusion tensor magnetic resonance imaging, and diffusion‐weighted magnetic resonance imaging. The functional methods considered were magnetic resonance spectroscopy, positron emission tomography, single photon emission computed tomography, and functional magnetic resonance imaging. Results: Results from studies using structural imaging techniques have revealed that chronic alcohol use is accompanied by volume reductions of gray and white matter, as well as microstructural disruption of various white matter tracts. These changes are partially reversible following abstinence. Results from functional imaging methods have revealed metabolic changes in the brain, lower glucose metabolism, and disruptions of the balance of neurotransmitter systems. Additionally, functional imaging methods have revealed increased brain activity in the mesocorticolimbic system in response to alcohol‐themed pictures relative to nondrug‐associated stimuli, which might be of predictive value with regard to relapse. Conclusions: There has been tremendous progress in the development of imaging technologies. Use of these technologies has clearly demonstrated the structural and functional brain abnormalities that can occur with chronic alcohol use. The study of the alcoholic brain provides an heuristic model which furthers our understanding of neurodegenerative changes in general, as well as their partial reversibility with sustained abstinence. Additionally, functional imaging is poised to become an important tool for generating predictions about individual brain functioning, which can then be used as a basis for personalized medicine.     

Hepatic focal nodular hyperplasia: the "star sign" on gadolinium-enhanced magnetic resonance angiography

BACKGROUND/AIMS: This study aimed at presenting the three-dimensional gadolinium-enhanced magnetic resonance angiography findings of hepatic focal nodular hyperplasia with angiographic correlation. METHODOLOGY: Three patients (one had abdominal pain, two were asymptomatic) with liver mass or nodules in the liver revealed on ultrasound underwent three-dimensional gadolinium-enhanced magnetic resonance angiography. Catheter angiography was available for correlation in all three cases. Other imaging studies including conventional magnetic resonance imaging in three patients, computed tomography in two and scintigraphy scan in one were reviewed. Surgical resection and biopsy were performed in one and two patients respectively. RESULTS: The ultrasound, computed tomography, magnetic resonance and scintigraphy findings were non-specific for focal nodular hyperplasia in all three patients. However, gadolinium-enhanced magnetic resonance angiography demonstrated tumor vessels radiating from its center to the periphery, which corresponded to the spokes of the characteristic "spoke-wheel" pattern on catheter angiography, producing the so called "star sign," that may suggest the diagnosis of focal nodular hyperplasia. Histopathologic examinations revealed focal nodular hyperplasia. CONCLUSIONS: This report highlights the usefulness of gadolinium-enhanced magnetic resonance angiography in the diagnosis of hepatic focal nodular hyperplasia by demonstrating the "star sign" and that computed tomography, scintigraphy, and catheter angiography may thus be obviated in such instances.     

An immunohistochemical study of neuropeptide Y in the bovine pineal gland

Abstract: An immunohistochemical study of the bovine pineal gland was performed using rabbit polyclonal antibodies raised against neuropeptide Y (NPY) or against the C-terminal flanking peptide of proNPY (CPON). A large number of NPY/CPON-immunoreactive (IR) nerve fibers were demonstrated throughout bovine pineal gland. The IR-fibers were located in the capsule of the gland, usually piercing into the gland together with blood vessels. In the gland itself, the fibers wen also located intraparenchymally between the pinealocytes. Within the rostral and caudal areas of the pineal stalk, NPY-IR fibers were also observed, and these fibers could be followed not only into the gland bul also to the habenular and posterior commissures. The morphological localization of the NPY-IR nerve fibers in the bovine pineal gland indicate that the majority of fibers originate from the superior cervical ganglion. However, some fibers probably originate from the brain itself.     

Presence of oxytocinergic neuronal-like cells in the bovine pineal gland: an immunocytochemical and in situ hybridization study

In the last decade, there is more and more evidence showing the role of the central innervation of the pineal gland, but there are controversies around the intra or extrapineal origin of oxytocin found within the pineal tissue. In order to check the amount and the site of synthesis of oxytocin in the bovine pineal gland, we performed a morphological and chromatographic study. The anatomical distribution of the pineal oxytocin was explored by immunohistochemistry and in situ hybridization for the corresponding mRNA. The results confirm the presence of oxytocinergic fibres in the bovine pineal, some of them endowed with big varicosities. Immunohistochemistry also displayed neuronal-like cells in the pineal body. The in situ hybridization for the mRNA encoding pre-pro/oxytocin-NFZ I used a mixture of three oligonucleotide probes labelled with (35)S. This allowed identification of positive cells in the bovine pineal. The content in oxytocin was evaluated by radioimmunoassay during 5 months, from July to November, and the peptidic extract revealed an increase of pineal oxytocin immunoreactivity in September as compared with July or November. The significance of intrinsic oxytocin innervation of the bovine pineal gland, as well as the threefold increase of the oxytocin content in the pineal in September, remains to be elucidated.     

Opioidergic innervation of the tree shrew pineal gland: An immunohistochemical study

Abstract: The tree shrew ( Tupaia glis ) has been described as a missing link relating primate to insectivore stock. The pineal gland of the tree shrew consists of a superficial pineal and a deep pineal, which are connected by long and slender pineal stalk. A monoclonal antibody against leu-enkephalin was used in an immunohistochemical investigation of the tree shrew pineal gland. A moderate innervation of leu-enkephalin immunoreactive nerve fibers has been demonstrated in both superficial and deep pineal gland of the tree shrew. The density of the nerve fibers was slightly higher in the superficial pineal than that of the deep one. The number of immunoreactive nerve fibers were observed in the capsule of the pineal gland from where they entered the pineal parenchyma. Only a few immunoreactive fibers were found in the habenular area and the area rostra1 to the pineal recess, connecting the habenula and the deep pineal. Furthermore, some positive fibers were located in the pineal stalk. There was no evidence of leu-enkephalin immunoreactive intrapineal cells as seen in the other species of mammal. Therefore, the interspecies variation of opioidergic innervation among the mammals may exist. The lack of intrapineal perikarya is interpreted to indicate that the sources of leu-enkephalin nerve fibers were outside the gland. The anatomical location of the leu-enkephalin immunoreactive nerve fibers in the tree shrew pineal gland supports to both central and peripheral pinealopetal pathways in this species.     

A case of pancreatic neuroendocrine tumor with multiple cystic components of various sizes

The patient was a 51-year-old woman who, while undergoing a thorough health checkup, was found to have a tumor (measuring 60 mm in diameter) in the tail of the pancreas by abdominal ultrasonography. Contrast-enhanced computed tomography revealed delayed contrast enhancement; the tumor also contained numerous low-absorption areas showing poor contrast enhancement. On magnetic resonance imaging, the tumor was visualized as having high signal intensity areas inside the tumor on T2-weighted images. Positron emission tomography revealed an abnormal accumulation in the area corresponding to the tumor. Endoscopic ultrasonography (EUS) revealed a relatively hyperechoic solid area, with a number of echo-free areas of various sizes that assumed a honeycomb appearance. EUS-guided fine needle aspiration was carried out targeting the solid area within the tumor, which led to a diagnosis of pancreatic neuroendocrine tumor (PNET). Histopathological examination of the resected specimen revealed that the tumor was composed of numerous cysts of various sizes and solid components. The cysts contained no evidence of necrosis or bleeding. Immunohistochemically, the cystic as well as solid components were CD56 (+), synaptophysin (+) and chromogranin A (+) with MIB1 labeling index of 5%. On the basis of these findings, the final diagnosis was PNET (G2).     

Tissue kallikrein in the rat pineal gland: An immunocytochemical study

Abstract: Tissue kallikrein in the rat pineal gland was immunocytochemically investigated with the aid of specific antiserum against rat urinary kallikrein. We also compared the tissue kallikrein immunoreactivity of the pineal gland with that of the submandibular gland and kidney, which have been well established as tissue kallikrein-synthesizing organs. The cytoplasm of pinealocytes from both the superficial and the deep portion of the gland exhibited specific immunolabeling for tissue kallikrein, but the immunoreaction was weaker than that observed in exocrine organs. Two types of tissue kallikrein-immunoreactive pinealocytes were distinguished; the first predominant type displayed moderate immunostaining, whereas a small number of cells, the second type, were so intensely labeled that their cytoplasmic processes were clearly outlined. The results of the present study suggest the existence of different types of pinealocytes and a potential physiological role of tissue kallikrein in the rat pineal gland.     

Prenatal development of the sheep pineal gland: An ultrastructural study

Abstract: The ultrastructure of the pineal gland of 32 sheep embryos was studied from day 54 of development through birth. Embryos were arranged in four age-groups, defined in terms of the most relevant histological features: group 1 (54 to 67 days of prenatal development), group 2 (71 to 92 days), group 3 (98 to 113 days), and group 4 (118 to 150 days). A primary cell type, designated the pinealoblast, was observed from 54 days until birth; ultrastructurally, this cell was found to contain all the organelles required for hormone synthesis. A second cell population, classified as interstitial cells by virtue of their location among pinealoblasts, appeared at 78 days gestation and persisted until birth. Interstitial cells were scarce and exhibited tropism for the perivascular space. From 118 days gestation until birth, a third cell type, termed the pigmented cell, was visible. Pigmented cells, whose ultrastructural characteristics differed from those of pinealoblasts, contained a large number of pigment granules of varying size and shape. The pineal gland of developing sheep embryos showed considerable innervation and abundant vascularization; this, together with certain ultrastructural characteristics, suggests that the gland has a secretory function in uterine life.