Deprivation of form vision suppresses diurnal cycling of retinal levels of leu-enkephalin

Deprivation of form vision by the fitting of translucent occluders suppressed the diurnal cycling of enkephalinergic amacrine cells (the ENSLI amacrine cells), in the chicken. Daily periods of normal vision or enforcing temporal contrast using strobe lighting appeared to restore normal functioning of the ENSLI cells. These results suggest that the ENSLI cells are involved in retinal circuits that assess the quality of the visual image and control eye growth.     

Retrorectal tumors: A challenge for the surgeons

Retrorectal or presacral tumors are rare lesions located in the presacral area and considered as being derived from multiple embryological remnants. These tumors are classified as congenital, neurogenic, osseous, inflammatory, or miscellaneous. The most common among these are congenital benign lesions that present with non-specific symptoms, such as lower back pain and change in bowel habit. Although congenital and developmental tumors occur in younger patients, the median age of presentation is reported to be 45 years. Magnetic resonance imaging plays a crucial role in treatment management through accurate diagnosis of the lesion, the evaluation of invasion to adjacent structures, and the decision of appropriate surgical approach. The usefulness of preoperative biopsy is still debated; currently, it is only indicated for solid or heterogeneous tumors if it will alter the treatment management. Surgical resection with clear margins is considered the optimal treatment; described approaches are transabdominal, perineal, combined abdominoperineal, and minimally invasive. Benign retrorectal tumors have favorable long-term outcomes with a low incidence of recurrence, whereas malignant tumors have a potential for distant organ metastasis in addition to local recurrence.     

Phenotypic variability of triphalangeal thumb-polysyndactyly syndrome linked to chromosome 7q36

Triphalangeal thumb-polysyndactyly (TPT-PS) is an isolated limb malformation consisting of pre- and postaxial polysyndactyly of hands and feet. The only family reported so far is of Dutch origin, and the genetic mapping study localized the TPT-PS locus at chromosome region 7q36 where the isolated triphalangeal thumb (TPT) anomaly has also been mapped. It was suggested that TPT-PS is a phenotypic variation of isolated TPT, and the same ancestral mutation may produce both phenotypes. Here we report on the second family with this malformation from the Turkish population. The characteristic findings in this family are triphalangeal thumb, webbing between 3rd, 4th, and 5th fingers associated with bony synostosis in the distal phalanges of the same fingers, and pre- and postaxial polysyndactyly of feet. Some individuals show a more severe phenotype with a complete syndactyly of all fingers giving a "cup-like" appearance to the hands. Genetic linkage study with DNA markers D7S1823, D7S550, D7S559, and D7S2423 demonstrated that this family is also linked to chromosome band 7q36. Identification of a second family from a distinct ethnic background suggests that TPT-PS and isolated TPT are not caused by the same ancestral mutation as it was originally anticipated.     

Adrenal neuroblastoma in an adult with tumor thrombus in the inferior vena cava

We describe the appearance of an adrenal neuroblastoma associated with tumor thrombus occurring in an adult patient. The tumor measured 14 x 12 x 12 cm, showed heterogeneous signal intensity on both T1-weighted and T2-weighted images, and displayed peripheral nodular enhancement on early post-gadolinium images. Tumor thrombus was identified within the inferior vena cava, which extended into the right atrium.     

Neuroendocrine tumors of the pancreas: spectrum of appearances on MRI

We reviewed our 8.5 year experience with magnetic resonance imaging (MRI) in the demonstration of neuroendocrine tumors of the pancreas using precontrast fat-suppressed T1-weighted, fat-suppressed T2-weighted, and serial post-gadolinium T1-weighted images, to describe the spectrum of appearances of these tumors. All MR examinations of patients with histologically proven neuroendocrine tumors were retrospectively reviewed. Histological type, tumor location, tumor diameter, signal intensity on precontrast images, enhancement patterns, and presence and appearance of metastases were determined. Twenty-two patients had histologically proved neuroendocrine tumors detected by MRI over the 8.5 year period. Histological types were gastrinoma (n = 8), insulinoma (n = 3), glucagonoma (n = 2), somatostatinoma (n = 1), VIPoma (n = 1), ACTHoma (n = 1), carcinoid (n = 1), and five untyped tumors. Primary tumors ranged in diameter from 1 to 6.2 cm. There was one histopathology-proven false-positive neuroendocrine tumor. The positive predictive value for MRI in the detection of these tumors was 96%. The most common appearance on precontrast images was low signal intensity on T1-weighted images and high signal intensity on T2-weighted images, which was observed in tumors in 18 of 22 patients. Moderate or intense early enhancement of all or portions of the primary tumors was observed in tumors in 19 of 22 patients either as uniform homogeneous, ring, or diffuse heterogeneous enhancement. Enhancement was minimal on these images in the other three patients. Gastrinomas enhanced in a ring pattern in 7 of 8 patients whereas the majority (9 of 11 patients) of noninsulinoma-nongastrinoma and untyped tumors enhanced in a diffuse heterogeneous fashion. Liver metastases were present in 13/22 patients including 3/8 with gastrinoma and 9/11 with noninsulinoma-nongastrinoma tumors. Most neuroendocrine tumors of the pancreas are low signal intensity on fat-suppressed T1-weighted images and moderately high in signal intensity on fat-suppressed T2-weighted images, although variations do exist. Tumors most often enhance in an early moderately intense fashion. Gastrinomas are often different in appearance than other neuroendocrine tumors in that they usually enhance in a ring fashion whereas nongastrinoma-noninsulinoma tumors usually enhance in a heterogeneous fashion.     

Pre and postnatal diagnosis of fetus‐in‐fetu

Differentiation of abdominal masses detected on prenatal ultrasound is difficult and requires careful characterization of the mass and precise localization. Differentiation is required in order to distinguish benign from potentially malignant conditions. We describe a case of fetus‐in‐fetu with pre and postnatal imaging.     

Giant adrenal cyst in a pregnant woman: a case report

In this case report, a rare example of a pregnant woman with a huge adrenal cyst is reported. No other published reports were found to have an outcome like the present case. A 27-year-old primiparous patient admitted to our clinic with complaints of gaining weight, abdominal distension and dyspnea. On physical examination abdominal distension was prominent. She weighed 78 kg. At abdominal ultrasonography, there was an 11 week, single live fetus within the uterine cavity. There was also an approximately 30 x 40 cm sized cyst. The origin of the cyst could not be detected by ultrasonography and magnetic resonance imaging. It was suspected to originate from the ovaries. Tumor markers and other laboratory tests were normal. Laparotomy was planned. During laparotomy, it was observed that there was a huge, thin capsulated cystic lesion filling the abdomen. The uterus and bilateral ovaries were normal. Eleven liters of yellow-colored fluid was drained from the cyst. At exploration, the cyst capsule was originating from a right adrenal lodge and was extirpated. The postoperative weight of the patient decreased to 67 kg. On the third postoperative day, the patient was discharged without any problems. The pathology result of the patient was reported as an epithelial adrenal cyst. The patient did not have any problems on antenatal follow up and had a cesarean delivery at term for cephalopelvic disproportion. A 3500 g, healthy female fetus was delivered.     

Hepatic adenomatosis: MRI demonstration with the use of superparamagnetic iron oxide

This case report describes a case of a 38-year-old woman with hepatic adenomatosis. MRI revealed five hyperintense nodular liver lesions on T1-weighted images which were hypo-isointense with the liver parenchyma on T2-weighted images. Serial gadolinium-enhanced images did not reveal distinctive imaging findings. With the use of superparamagnetic iron oxide (SPIO) particles, hyperintense adenomas revealed signal loss on T1-weighted images after SPIO. Two subcapsular adenomas were resected based on MRI findings and histopathology confirmed MRI diagnosis.     

Adult intussusception secondary to inflammatory fibroid polyp: demonstration by MRI

Adult intussusception secondary to inflammatory polyp occurs rarely. Imaging of intussusception on ultrasound, CT and MRI has been previously described. In this report we describe a case of an adult intussusception secondary to inflammatory fibroid polyp. Both the lead point (inflammatory fibroid polyp) and intussusception were depicted on multiplanar MR images. Findings on MRI were confirmed at surgery and histopathological examination. Received: 11 January 2000; Revised: 3 May 2000; Accepted: 4 May 2000