Development of a Giant Cornu Cutaneum in a Patient with a Coincidental Foreknown Intracranial Meningioma.

The diagnostic spectrum for scalp lesions is extensive and comprises either benign or malignant features. Cornu cutaneum (CC) is a well-recognized condition; however, its origin and natural course are not always obvious. We present the case of a 78-year-old male patient who was diagnosed with intracranial meningioma in 2014 and who subsequently refused treatment. He presented a new scalp lesion, resembling a horn, in the vertex region 1.5 years after his last follow-up. The lesion was excised, and the patient was histopathologically diagnosed as having CC caused by squamous cell carcinoma. CC can be easily recognized when it resembles animal horn; however, it can assume different shapes that require a physician to be vigilant. Moreover, a lesion’s benign or malignant nature is not obvious in all cases. Hard, protruding scalp lesions should be examined for CC, and a histopathological evaluation should be performed to make a definitive diagnosis.

Two Uncommon Sites of Metastasis: Breast and Hypophysis Metastases of Head and Neck Adenoid Cystic Carcinoma Detected by FDG PET/CT.

Adenoid cystic carcinoma (ACC) is a rare epithelial malignancy arising from secretory glands, particularly the salivary glands. It tends to invade nerves and has a high potential for distant hematogenous metastasis, especially to the lungs, bone, liver and brain. The breast and hypophysis are not common sites of ACC metastatic disease. Herein, we report a case of ACC of the head and neck region with two unusual sites of metastases, the hypophysis and breast.

Reversible Splenial Lesion Syndrome After Intravenous Immunoglobulin Treatment for Guillain-Barre Syndrome.

Reversible corpus callosum splenial (CCS) lesions have been described in patients with varied etiologies. The most common causes of previously reported reversible focal lesions of the CCS are viral encephalitis, antiepileptic drug toxicity/withdrawal, and metabolic disorders. Intravenous immunoglobulin (IVIG) therapy is used for different immune-mediated diseases. It is generally safe, and serious adverse reactions are uncommon. We presented a rare case of disturbed consciousness with reversible CCS lesions after IVIG therapy for Guillain-Barre syndrome in an adult woman. In this case, we believe that IVIG therapy caused reversible CCS lesions with encephalopathy and probably result of cytotoxic edema and/or cerebral arterial vasospasm.

Application of Diffusion-Weighted Imaging in the Detection of Active Sacroiliitis and the Comparison of Apparent Diffusion Coefficient and Relative Apparent Diffusion Coefficient Values.

OBJECTIVES: This study aims to evaluate the role of diffusion-weighted imaging in detection of active sacroiliitis and compare the apparent diffusion coefficient (ADC) and normalized relative ADC (r-ADC) values by using vertebra and iliac wings as reference organs. PATIENTS AND METHODS: The study included 56 patients (26 males, 30 females; mean age 37.7±10.1 years; range 18 to 66 years) with chronic back pain and without history of sacroiliitis who underwent magnetic resonance imaging. T2-weighted spectral presaturation with inversion recovery, contrast-enhanced T1-weighted spectral presaturation with inversion recovery, and diffusion-weighted (b values: 0 and 600 s/mm2) images were obtained. All images were evaluated by two different radiologists for interobserver variability. All individuals were grouped in either mechanical low back pain (control group) or active sacroilitis (disease group) groups according to the presence or absence of MRI findings of active sacroilitis. ADC values of both surfaces were measured from normal and affected areas of joints. Also, ADC values of L5 vertebra and iliac wings were measured as reference organs to calculate r-ADC values. RESULTS: Mean ADC and r-ADC values measured from lesions were significantly higher than that of normal appearing bone marrow areas in both patients with mechanical low back pain (n=17) and active sacroiliitis (n=39). Both ADC values and r-ADC values could differentiate active lesions from normal appearing bone marrow areas as well as contrast-enhanced T1-weighted images. According to r-ADC values calculated with the L5 vertebra, unaffected portions of bone marrow areas in patients with sacroiliitis were normalized whereas r-ADC remained higher than normal in affected portions of the bones. CONCLUSION: Diffusion-weighted imaging is a fast, sensitive magnetic resonance imaging sequence in detection of active sacroiliitis. It does not require contrast agent and can be safely used as an adjunct to conventional magnetic resonance images. r-ADC is also highly sensitive in detecting active sacroiliitis and may be used as an alternative to standard ADC measurements for the demonstration of inflammation. It helps eliminate individual bone marrow differences by using patients' own normal bone marrow measurements and increases diagnostic accuracy.

Distinctive Characteristic Features of Intramedullary Hemangiopericytomas.

STUDY DESIGN: The retrospective analysis of intramedullary hemangiopericytomas (HPCs) was performed, and the entity was discussed in accordance with the literature findings. PURPOSE: This study aimed at defining distinctive characteristic features of intramedullary HPC with respect to surgical approach and prognosis. OVERVIEW OF LITERATURE: Intramedullary HPCs are extremely rare tumors. They originate from capillary pericytes, supposedly follow the vessels over the spinal cord, and infiltrate deep into the spinal cord without a distinct plane. Their treatments and prognosis are not well-defined in the literature. METHODS: Our database was retrospectively reviewed for the cases of HPCs. Later on, a literature search was performed to reveal all reported cases of intramedullary HPCs. The following key words were searched in PubMed databases: "hemangiopericytoma and intramedullary," "hemangiopericytoma and spine (spinal) and intradural," and "hemangiopericytoma and spinal cord." The articles were reviewed for patients' demographics features, imaging characteristics, tumor-specific factors (surgical technique, pathological descriptions, and world health organization grades), and postoperative course and prognosis (adjuvant therapies, recurrences, complications, and mortalities). RESULTS: A total of seven patients (three male and four female) was reached, with their ages ranging from 15 to 80 years (mean, 32.5 years). The tumors were located majorly in thoracic region (5/7, 71.4%), and only two cases were in the cervical region (2/7, 28.6%). All tumors were completely removed, and only two cases received radiotherapy. No recurrence was reported. CONCLUSIONS: Complete resection of the intramedullary HPCs seems to be the best management strategy for long-term and recurrence-free survival and in alleviating further need for radiotherapy.

The melatonin receptor MT1 is required for the differential regulatory actions of melatonin on neuronal 'clock' gene expression in striatal neurons in vitro.

Through inhibitory G protein-coupled melatonin receptors, melatonin regulates intracellular signaling systems and also the transcriptional activity of certain genes. Clock genes are proposed as regulatory factors in forming dopamine-related behaviors and mood and melatonin has the ability to regulate these processes. Melatonin-mediated changes in clock gene expression have been reported in brain regions, including the striatum, that are crucial for the development of dopaminergic behaviors and mood. However, it is not known whether melatonin receptors present in striatum mediate these effects. Therefore, we investigated the role of the melatonin/melatonin receptor system on clock gene expression using a model of primary neuronal cultures prepared from striatum. We found that melatonin at the receptor affinity range (i.e., nm) affects the expression of the clock genes mPer1, mClock, mBmal1 and mNPAS2 (neuronal PAS domain protein 2) differentially in a pertussis toxin-sensitive manner: a decrease in Per1 and Clock, an increase in NPAS2 and no change in Bmal1 expression. Furthermore, mutating MT1 melatonin receptor (i.e., MT1 knockouts, MT1(-/-)) reversed melatonin-induced changes, indicating the involvement of MT1 receptor in the regulatory action of melatonin on neuronal clock gene expression. Therefore, by controlling clock gene expression we propose melatonin receptors (i.e., MT1) as novel therapeutic targets for the pathobiologies of dopamine-related behaviors and mood.

Drug- and region-specific effects of protracted antidepressant and cocaine treatment on the content of melatonin MT(1) and MT(2) receptor mRNA in the mouse brain.

OBJECTIVES: In the mammalian brain, G protein-coupled MT(1) and MT(2) melatonin receptors may be involved in Alzheimer's pathology, long-term potentiation, depression, and in the behavioral effects of psychoactive drugs. These drugs; e.g. antidepressants and drugs of abuse, are typically used over long periods of time and may alter neuroplasticity and gene expression. We hypothesized that such antidepressant- and cocaine-altered expression of melatonin receptor mRNA may occur in the hippocampus and striatum. METHODOLOGY: Male C3H/HeJ mice were treated with the antidepressants fluoxetine, desipramine, and clomipramine, with the psychostimulant cocaine, and with a vehicle either a single time or once a day for 14 days. Brain samples were collected 24 h after the last injection and the content of MT(1) and MT(2) mRNA was assayed. RESULTS: A single drug injection did not alter the MT(1) and MT(2) mRNA content. In the hippocampus, protracted treatment with antidepressants increased the amount of MT(1) mRNA (with the exception of fluoxetine) but decreased MT(2) mRNA content; cocaine did not produce any alterations. In the striatum, antidepressants produced the opposite effect on MT(1) mRNA content; they decreased it. They did not significantly alter striatal MT(2) mRNA (we observed a nonsignificant trend to a decrease). Cocaine also decreased striatal MT(1) mRNA content without affecting MT(2) mRNA. CONCLUSION: These results suggest that drug- and region-specific alterations of MT(1)/MT(2) mRNA produced by protracted antidepressants and cocaine treatment may alter MT1/MT2 expression and contribute to long-term neuroplastic effects of these drugs.

Drosophila GABA(B) receptors are involved in behavioral effects of gamma-hydroxybutyric acid (GHB).

Gamma-hydroxybutyric acid (GHB) can be synthesized in the brain but is also a known drug of abuse. Although putative GHB receptors have been cloned, it has been proposed that, similar to the behavior-impairing effects of ethanol, the in vivo effects of pharmacological GHB may involve metabotropic gamma-aminobutyric acid (GABA) GABA(B) receptors. We developed a fruitfly (Drosophila melanogater) model to investigate the role of these receptors in the behavioral effects of exogenous GHB. Injecting GHB into male flies produced a dose-dependent motor impairment (measured with a computer-assisted automated system), which was greater in ethanol-sensitive cheapdate mutants than in wild-type flies. These effects of pharmacological concentrations of GHB require the presence and activation of GABA(B) receptors. The evidence for this was obtained by pharmacological antagonism of GABA(B) receptors with CGP54626 and by RNA interference (RNAi)-induced knockdown of the GABA(B(1)) receptor subtype. Both procedures inhibited the behavioral effects of GHB. GHB pretreatment diminished the behavioral response to subsequent GHB injections; i.e., it triggered GHB tolerance, but did not produce ethanol tolerance. On the other hand, ethanol pretreatment produced both ethanol and GHB tolerance. It appears that in spite of many similarities between ethanol and GHB, the primary sites of their action may differ and that recently cloned putative GHB receptors may participate in actions of GHB that are not mediated by GABA(B) receptors. These receptors do not have a Drosophila orthologue. Whether Drosophila express a different GHB receptor should be explored.

[Case report: Tenosynovial giant cell tumor arising from the knee joint]. / Diz ekleminde yerlesim gösteren tenosinovyal dev hücreli tümör.

Giant cell tumor of the tendon sheath and synovium or pigmented villonodular synovitis of the tendon is a benign neoplasm, although there are rarely reported malignant metastatic forms. The most common location is the hand. Large joints such as the ankle and knee are infrequently affected. Diagnosis might be suspected radiologically, but the exact diagnosis has to be confirmed by histopathologic examination. In this study, we report MRI findings of three giant cell tumors of the tendon sheath.