Nerve Elements Research Articles

Nerves in the intersphincteric space of the human anal canal with special reference to their continuation to the enteric nerve plexus of the rectum

In the intersphincteric space of the anal canal, nerves are thought to "change" from autonomic to somatic at the level of the squamous-columnar epithelial junction of the anal canal. To compare the nerve configuration in the intersphincteric space with the configuration in adjacent areas of the human rectum, we immunohistochemically assessed tissue samples from 12 donated cadavers, using antibodies to S100, neuronal nitric oxide synthase (nNOS), and tyrosine hydroxylase (TH). Antibody to S100 revealed a clear difference in intramuscular nerve distribution patterns between the circular and longitudinal muscle layers of the most inferior part of the rectum, with the former having a plexus-like configuration, while the latter contained short, longitudinally running nerves. Most of the intramural ganglion cells in the anal canal were restricted to above the epithelial junction, but some were located just below that level. Near or at the level of the epithelial junction, the nerves along the rectal adventitia and Auerbach's nerve plexus joined to form intersphincteric nerves, with all these nerves containing both nNOS-positive parasympathetic and TH-positive sympathetic nerve fibers. Thus, it was histologically difficult to distinguish somatic intersphincteric nerves from the autonomic Auerbach's plexus. In the intersphincteric space, the autonomic nerve elements with intrapelvic courses seemed to "borrow" a nerve pathway in the peripheral branches of the pudendal nerve. Injury to the intersphincteric nerve during surgery may result in loss of innervation in the major part of the internal anal sphincter.

Ultrastructural Changes in the Nerves of the Gums in Rats with Spontaneous Arterial Hypertension and Their Modifications Related to Pharmacotherapy

In SHR rats with clearly pronounced arterial hypertension, we studied ultrastructural changes in nerve elements of the gums, as well as modifications of such changes in animal groups subjected to pharmacological correction of hypertension (using bisoprolol, thiotriazoline, and quercetin). In animals with a high arterial pressure, we found significant ultrastructural disorders in myelinated nerve fibers and intense apoptotic changes in neurolemmal cells. In this situation, thiotriazoline (used with a therapeutic aim) demonstrated significant inhibitory effect with respect to apoptosis and also neuroprotective properties.

Retinoic acid influences antero‐posterior positioning of peptidergic neurons in the planula larva of the hydrozoan Clava multicornis

AbstractRetinoic acid (RA) is a derivative of vitamin A known to be involved in the regulation of many developmental and physiological processes in chordates. Recently, evidence showing its presence and function in invertebrate deuterostomes and protostomes indicated the early evolutionary origin and conservation of the RA developmental machinery, with a key role also in neural differentiation. Moreover, it is known that retinoids can influence pattern specification in polyps of the hydroid Hydractinia echinata. The planula larvae of the hydrozoan Clava multicornis are characterized by a complex nervous system formed by a frontal neural plexus composed by two distinct peptidergic cell populations with antero‐posterior organization: a first, anterior‐most GLWamide immunoreactive (GLW‐IR) population and an RFamide immunoreactive (RF‐IR) cell belt just posterior to the first population. In contrast to most swimming planulae, C. multicornis larvae display a smooth gliding movement on the substrate, characterized by alternate bending of the anterior pole. We tested the effects of RA and of a RA antagonist on C. multicornis development by analyzing the nervous system organization and the photoresponsive behavior of larvae exposed to RA during their embryogenesis. After the exposure, the nervous system became completely disorganized, leading to the displacement of RFamide‐IR cells. Moreover, RA‐treated larvae did not exhibit the typical phototropic behavior of control specimens. Our results suggest that RA can alter the normal development of nervous elements in this hydroid species, supporting the hypothesis that the morphogenetic activity of RA predates the origin of chordates.

Fine needle aspiration cytology as an aid to diagnosis, categorization and treatment when pure neuritic leprosy presents as nerve abscess

Background:Pure neuritic leprosy (PNL) usually presents with neurological symptoms without skin involvement. Fine needle aspiration can play an important role in the management of PNL cases presenting as nerve abscesses.Aim:To assess the role of fine needle aspiration cytology (FNAC) in diagnosing and categorizing PNL cases presenting as nerve abscesses in the absence of neurological symptoms.Materials and Methods:Five patients with subcutaneous nerve related swellings without clinically evident neurological deficits were subjected to FNAC. As the cytological features were suggestive of nerve abscesses due to leprosy, Fite stain was performed in all cases. As none of the patients had any leprosy skin lesions, they were diagnosed as cases of PNL. Features like cellularity, caseous necrosis, presence or absence of lymphocytes, macrophages, epithelioid cells, granulomas, Langhans giant cells and nerve elements were analyzed with the bacteriological index, to categorize PNL according to the Ridley-Jopling classification.Results:Based on the cytological features and bacteriological indices, 3 cases were cytologically categorized into tuberculoid (TT)/borderline tuberculoid (BT) leprosy and the other two, as BT/borderline lepromatous (BL) and BL leprosy respectively in spite of having similar clinical presentation. Based on the cytological diagnoses, category-specific treatment could be instituted with clinical improvement.Conclusions:The simple and minimally invasive FNAC procedure allows diagnosis and a reasonably accurate categorization of PNL presenting as nerve abscess and therefore, highly useful in its clinical management.

Neuromuscular choristoma: characteristic magnetic resonance imaging findings and association with post-biopsy fibromatosis

To describe imaging characteristics of neuromuscular choristomas (NMC) and to differentiate them from fibrolipomatous hamartomas (FLH). Clinical and imaging characteristics of six patients with biopsy-proven NMC and six patients with FLH were reviewed by musculoskeletal, a pediatric, and two in-training radiologists with a literature review to define typical magnetic resonance imaging features by consensus. Five radiology trainees blinded to cases and naive to the diagnosis of NMC and a musculoskeletal-trained radiologist rated each lesion as having more than or less than 50% intralesional fat, as well as an overall impression using axial T1 images. Sensitivity, specificity, accuracy, and interobserver agreement kappa were determined. Typical features of NMC include smoothly tapering, fusiform enlargement of the sciatic nerve or brachial plexus elements with T1 and T2 signal characteristics closely following those of muscle. Longitudinal bands of intervening low T1 and T2 signal were often present and likely corresponded to fibrous tissue by pathology. Four of five patients with long-term follow-up (80%) developed aggressive fibromatosis after percutaneous or surgical biopsy. Nerve fascicle thickening often resulted in a "coaxial cable" appearance similar to classic FLH, however, using a cutoff of <50% intralesional fat allowed for differentiation with 100% sensitivity by all reviewers and 100% specificity when all imaging features were utilized for impressions. Agreement was excellent with all differentiating methods (kappa 0.861-1.0). NMC can be confidently differentiated from FLH and malignancies using characteristic imaging and clinical features. When a diagnosis is made, biopsy should be avoided given frequent complication by aggressive fibromatosis.

The impact of local anesthetic distribution on block onset in ultrasound‐guided interscalene block

Recent investigations of local anesthetic distribution in the lower extremity have revealed that completely surrounding the sciatic nerve with local anesthetic provides the advantage of more rapid and complete anesthesia in the territory served by the nerve. We hypothesized that a pattern of distribution that entirely envelops the targeted nerve roots during interscalene block would provide similar benefits of more rapid anesthesia onset. During interscalene block guided by ultrasound with nerve stimulator confirmation, the pattern of local anesthetic distribution was recorded and later classified as complete or incomplete envelopment of the visible nerve elements in 50 patients undergoing ambulatory shoulder arthroscopic surgery. The pattern was then compared with the extent of block setup at pre-determined intervals, as well as to post-operative pain levels and block duration. Twenty-two patients (44%) had complete envelopment of the nerves in the plane of injection during ultrasound imaging of the interscalene block. There was no difference in the fraction of blocks that were fully set-up at 10 min with regards to complete or incomplete envelopment of the nerves by local anesthetic. All of the patients had complete setup of the block by 20 min. In addition, the post-operative pain levels and duration of block did not vary among the two groups with complete vs. incomplete local anesthetic distribution around the nerves. The presence or absence of complete envelopment of the nerve elements in the interscalene groove by local anesthetic did not determine the likelihood of complete block effect at pre-determined time intervals after the procedure.

Role of Free Flaps in the Management of Craniofacial Neurofibromatosis: Soft Tissue Coverage and Attempted Facial Reanimation

o o p Neurofibromatosis (NF) is a rare inherited disorder occurring in 1 of 3,000 births. Although NF has been previously classified into 9 different categories, the 3 main forms are neurofibromatosis 1 (NF1), neurofibromatosis 2 (NF2), and schwannomatosis. Ninety ercent of cases of NF are NF1 (von Recklinghausen isease). Histologically, the disease shows proliferaion of peripheral nerve elements (Schwann cells, erineural cells, fibroblasts), which are of neural crest rigin. The disease is inherited in an autosomal domnant pattern, with complete penetrance and variable xpressivity. The gene for NF1 is located on the long rm of chromosome 17. NF progresses slowly and irregularly, with accelerations noted during puberty and pregnancy. Tumors may initially appear at birth r at puberty and continue to develop through adultood. The head and neck are involved in 3% to 7% of all F cases. Similarly, craniofacial neurofibromatosis CN) is almost universally NF1 and commonly of the

Selective survival of calretinin- and vasoactive-intestinal-peptide-containing nerve elements in human chagasic submucosa and mucosa

Chronic Chagas' disease is frequently characterized by massive myenteric neuron loss resulting in megacolon with severely and irreversibly disturbed motility. Here, we focused on two submucosal neuron populations, immunoreactive for calretinin (CALR) or somatostatin (SOM), and their respective mucosal nerve fibres in chagasic megacolon. Surgically removed megacolonic segments of seven chagasic patients were compared with seven age- and region-matched non-chagasic control segments. Evaluation included immunohistochemical triple-staining of cryosections for CALR, SOM and peripherin or for CALR and vasoactive intestinal peptide (VIP) and of submucosal whole-mounts for CALR, SOM and the pan-neuronal marker anti-HuC/D. Submucosal neuron counts in chagasic tissue revealed neuron numbers reduced to 51.2% of control values. In cryosections, nerve fibre area measurements revealed 8.6% nerve fibre per mucosal area in control segments, but this value decreased to 1.5% in megacolonic segments. In both evaluations, a disproportionate decrease of SOM-reactive nerve elements was observed. The proportions of SOM-positive neurons related to the total neuron number declined to 2% (control 10%) and the proportion of SOM-reactive mucosal nerve fibres related to the whole mucosal area to 0.014% (control 1.8%)in chagasic tissue. The second set of cryosections revealed extensive colocalization of CALR with VIP in both surviving submucosal perikarya and mucosal nerve fibres. We suggest that VIP, a neuroprotective and neuroeffectory peptide typically contained in submucosal neurons, allows both the VIP-containing neurons to endure and the patients to survive by maintaining their mucosal barrier, despite the almost complete loss of colonic motility for decades.

The topography of the NO- and H2S-systems in the brain of the mitten crab Eriocheir japonica (De Haan, 1835) (Decapoda: Varunidae)

235 Among a number of signal systems of the central nerve system (CNS) that are involved in adaptive pro� cesses of organisms, an important role is played by endogenous gaseous mediators, viz., nitric oxide (NO) and hydrogen sulfide (H2S). The effects of these medi� ators are directed to the preservation of intracellular homeostasis and control of the most important physi� ological processes, both in the norm and in pathologi� cal conditions (13, 34). Nitric oxide, which is synthe� sized by the enzyme NOsynthase, is better studied. It has been shown that NOS is found in cells of verte� brate and invertebrate animals colocalized with the Abstract—The distributions and activities of nitric oxide (NO) and hydrogen sulfide (H2S) synthesis enzymes in the brain of the mitten crab Eriocheir japonica (Decapoda: Varunidae) from fresh and salt water were studied using histochemical and immunocytochemical methods. In crabs that live in fresh water, the share of NOand CBScontaining nerve elements in ce rtain brain structures was increased, indicating the joint participation of NO and H2S in the central regulation of adaptive mechanisms during the formation of a compensatory response to changing environmental conditions. It is assumed that preservation of the bal� ance between nitric oxide and hydrogen sulfide in the brain of E. japonica plays an important role in the adap� tation of this species to changes in the chemical composition of the environment.

Study of the vesicular cycle in nerve structures in somatic muscle of earthworm (Lumbricus terrestris)

In the muscle wall of the earthworm Lumbricus terrestris, with the aid of fluorescent endocytotic dyes FM1-43, FM2-10, and FM4-64, there are revealed fluorescent spots 1–2 μm in diameter that represent clusters of “synaptic boutons.” Application takes place onto ganglia of the abdominal nerve chain of the Dil membrane probe capable of translocation by axoplasmic transport; the subsequent (next day) staining of nerve structures with the endocytotic marker FM4-64 showed the complete superposition of fluorescence of these dyes fluorescing in different specter areas. The fluorescent marker DiBAC4(3) revealed an enhancement of fluorescence of nerve elements with increase of K+ concentration in the extracellular medium. Use of FM2-10 showed that, the higher the K+ content in solution and, accordingly, the nerve cell depolarization, the faster the release of the marker and, on the contrary, the slower the process in the absence of K+ in the medium. In the Ca2+-free solution and in the presence of the Ca2+ chelator BAPTA or BAPTA-AM, there uptake and release of FM2-10 are blocked, but only after preliminary 40-min incubation in such solution. In clusters of synaptic boutons, exo- and endocytosis processes take place that are also preserved under conditions of rest. This vesicular cycle depends on the membrane potential of nerve structures and on the content of K+ and Ca2+ in the medium, the calcium sensor working most likely by the “all or nothing” principle.

Tentacular apparatus ultrastructure in the larva ofBolinopsis infundibulum(Lobata: Ctenophora)

Borisenko, I. and Ereskovsky, A.V. 2011. Tentacular apparatus ultrastructure in the larva of Bolinopsis infundibulum (Lobata: Ctenophora). —Acta Zoologica (Stockholm) 00: 1–10. Most ctenophores have a tentacular apparatus, which plays some role in their feeding. Tentacle structure has been described in adults of only three ctenophore species, but the larval tentacles have remained completely unstudied. We made a light and electron microscopic study of the tentacular apparatus in the larvae of Bolinopsis infundibulum from the White Sea. The tentacular apparatus of B. infundibulum larvae consists of the tentacle proper and the tentacle root. The former contains terminally differentiated cells, while the latter contains stem cells and cells undergoing differentiation. The core of the tentacle is formed by myocytes, and its epidermis contains colloblasts (hunting cells), wall cells, degenerating cask cells, refractive vesicles, and ciliated sensory cells. Stem cells, colloblasts, and cask cells at various stages of differentiation and putative myocytes progenitors were revealed in the tentacle root. Two different populations of the stem cells in the tentacle root give rise to epidermal (colloblasts and cask cells) and mesogleal (myocytes) cell lines. Nervous elements, glandular cells, and basal lamina were not found. Step-by-step differentiation of colloblasts and cask cells is described.

Sonoanatomy of the vasculature at the supraclavicular and interscalene regions relevant for brachial plexus block

Our aim in this observational study was to utilize ultrasound, as well as anatomic dissection, to document the frequency with which branches of the subclavian vessels are found in close association with the brachial plexus at the locations of supraclavicular and interscalene brachial plexus block. Ultrasound was utilized to document the presence of branches of the subclavian vein and artery, adjacent to the brachial plexus in the supraclavicular and in the interscalene region in 50 patients undergoing shoulder surgery. The position, depth, and dimensions of the vessels were described, and the origin determined when possible. In addition, the posterior triangle of the neck on both sides of three non-preserved cadavers was dissected to evaluate the vascular anatomy and correlate the ultrasound findings. Ultrasound scanning revealed an arterial branch adjacent to, or passing directly through, the brachial plexus in the supraclavicular region in 43/50 (86%) patients. Within the interscalene region, an artery was identified coursing in a lateral direction in 45/50 (90%) of cases, while a corresponding small vein, coursing medial to lateral in this area, was noted in 23/50 (46%) of cases. Small branch vessels from the subclavian artery and vein were frequently evident, on ultrasound imaging, in close association with the nerve elements of the brachial plexus in the supraclavicular and interscalene regions. Appreciation of the presence of these vessels and their likely origin and course will aid the anesthesiologist in planning a safe nerve block.

Ultrastructural Evidence of Kisspeptin-Gonadotrophin-Releasing Hormone (GnRH) Interaction in the Median Eminence of Female Rats: Implication of Axo-Axonal Regulation of GnRH Release

The present study was conducted to determine the morphological and functional interaction between kisspeptin and gonadotrophin-releasing hormone (GnRH) neuronal elements at the median eminence in female rats to clarify a possibility that kisspeptin directly stimulates GnRH release at the nerve end. A dual immunoelectron microscopic study of kisspeptin and GnRH showed that the kisspeptin-immunoreactive nerve element directly abutted the GnRH-immunoreactive nerve element, although no obvious synaptic structure was found between kisspeptin and GnRH neurones in the median eminence. The current retrograde tracing study with FluoroGold (FG) indicates that kisspeptin neurones are not in contact with fenestrated capillaries because no FG signal was found in kisspeptin neurones when the FG was injected peripherally. This peripheral FG injection revealed the neuroendocrine neurones projecting to the median eminence because FG-positive GnRH neuronal cell bodies were found in the preoptic area. Synthetic rat kisspeptin (1-52)-amide stimulated GnRH release from the median eminence tissues in a dose-dependent manner. Thus, the present results suggest that kisspeptin at least partly exerts stimulatory effects on GnRH release from the neuronal terminals of GnRH neurones by axo-axonal nonsynaptic interaction in the median eminence.

Anomalies of Thoracic Outlet in Human Fetuses: Anatomical Study

Thoracic outlet syndrome (TOS) identifies the clinical condition determined by the mechanical compression and entrapment of the subclavian vessels and the brachial plexus cords within the space delineated by the scalene muscles, the clavicle, and the first rib. To date, there are no concluding explanations concerning the real causes of the appearance of TOS in children. This is the first study to investigate the existence, frequency, and type of thoracic outlet anomalies in the prenatal stage (human fetuses). Eighty cervical dissections (40 consecutive spontaneously aborted human fetuses) were performed, and the musculoskeletal, vascular, and nervous elements that pass through the thoraco-cervico-axillary region were investigated. Overall, anatomical anomalies of the thoraco-cervico-axillary region were found in 60% of the 80 cervical dissections. Nine (22.5%) of the 40 fetuses had normal bilateral anatomy. In 6.3%, the scalene hiatus had an oval shape due to the common costal insertion of the anterior and middle scalene muscles. Fibromuscular bands were found in 15% of the fetuses. Hypertrophy of the anterior scalene muscle was seen in 12.5% of the dissections. In 28.7% of the cervical dissections, hypertrophy of the C7 transversal process was noted, bilateral in seven cases. There was one case of a "C-shaped" clavicle anomaly. The absence of the internal mammary artery was noted in one case. This study shows that the presence of TOS anomalies in fetuses is not a rare occurrence, emphasizing a pathological cervical background which can be harmful in situations of cervical trauma or inflammatory processes. Having knowledge of the types of anomalies which can lead to TOS is important for performing a complete surgical correction and avoiding the high failure rate of recurrent TOS.

Dynamic versus rigid stabilization for the treatment of disc degeneration in the lumbar spine

Study design: Retrospective cohort study.Clinical question: This study aimed to describe the outcome of stabilization surgery with dynamic instrumentation for degenerative disc disease. The results were compared with age- and gender-matched peers treated with traditional fusion with rigid instrumentation. If necessary, additional nerve elements decompression was undertaken in both groups.Methods: This study analyzed the success rates of 25 patients aged 47.4 years (mean 95% confidence interval: 43.1–51.7) treated with stabilization of the involved vertebral dynamic unit(s) with either dynamic or rigid instrumentation with or without additional decompression. Clinical outcome was assessed with Oswestry disability index (ODI) and visual analogue scale (VAS) for back pain, leg pain, and activity level. Satisfaction outcome was measured with Stauffer and Coventry overall satisfaction criteria and VAS for satisfaction. Health-related quality of life was estimated with Short Form-36 (SF-36) questionnaires. Fusion rate and adjacent level(s) was checked with x-ray. Complications recorded in patients' files were evaluated and revision surgeries were stated as treatment failures.Results: At the 4-year follow-up (range, 2–5 years) significant improvement was noted on some subjective parameters in both groups. No statistical differences were seen between the groups at final follow-up. Five patients (42%) in the rigid group and two patients (20%) in the dynamic group were rated good or excellent according to the overall Stauffer and Coventry satisfaction criteria. Radiologically, seven patients (58%) in the rigid group were undoubtedly fused and all the involved discs in the dynamic group continued to degenerate. Adjacent segments showed loss of disc height in both groups but only loss of upper adjacent discs in the rigid group was statistically significant. Two patients in the dynamic group and one patient in the rigid group required reoperation because of the pedicle screw misplacement.Conclusion: The results of this study indicate no significant difference between dynamic and rigid stabilization of the lumbar spine for patients with degenerative disc disease (DDD). However, the study is underpowered and further studies on larger and homogeneous group of patients should be undertaken.Final class of evidence (CoE)-treatmentYesStudy design: Prospective cohort Retrospective cohort• Case control Case seriesMethods Patients at similar point in course of treatment• Follow-up ≥85%• Similarity of treatment protocols for patient groups• Patients followed-up long enough for outcomes to occur Control for extraneous risk factorsOverall class of evidenceIIIThe definition of the different classes of evidence is available on page 59.

Electron microscopic study of intestinal epithelium of Saccoglossus mereschkowskii (Enteropneusta, Hemichordata)

Epithelium of the hepatic region of the intestine in Saccoglossus mereschkowskii, a representative of enteropneusts (Enteropneusta, Hemichordata) standing at the base of Chordata, has been investigated using electron microscope. The ultrastructure of ciliated and granular epithelial cells, elements of the intraepithelial nerve layer, and intercellular junctions have been characterized. The data concerning details of the organization of the ciliary apparatus and rootlets system are presented. It is justified the presence of complicated supporting construction of cilia which performs a mechanical stabilizing function and possibly also provide synchronization of ciliary movements. The presence of cilia with two centrioles is considered as an adaptation to high functional load on ciliary apparatus. Well developed bundles of myofilaments are found in the cytoplasm of the basal portions of ciliary cells that characterizes these cells as myoepithelial. The features indicating the role of ciliary cells in absorption are described. The capability of these cells to balloon-like secretion is considered. Data on the accumulation of food reserves in the form of lipid droplets and glycogen in the cell cytoplasm are presented. Ciliated cells are characterized by their function as ciliated secretory-absorptive myoepithelial cells. Based on the location of secretory granules both in the apical and basal portions of granular cells, an exocrine-endocrine function of these cells has been suggested. Typical endocrine cells in the intestinal epithelium of S. mereschkowskii are absent. Several types of granules in the nerve fibers cytoplasm are described. Junctions between the nerve fibers and basal portions of ciliary and granular epithelial cells are found. Nerve regulation of contractile and secretory functions of epithelial cells is supposed. The presence of the regulatory nerve-endocrine system that includes receptor cells of open type, secretory endocrine-like cells and nerve elements of nerve layer is supposed in the intestinal epithelium of enteropneusts.

Synchronization Mechanisms in Local Neural Networks in the Neocortex. Modeling and Experimental Studies

Measures of excitation and inhibition were studied in cat visual cortex neurons and the time parameters of epileptiform activity were studied in rat sensorimotor cortex neurons. The results were used to construct a simulation model of a neural network in the Neiroimitator program, and this was used to investigate synchronization mechanisms. The neural network consisted of 30 neurons with different excitation and inhibition time parameters. Studies were performed with the neural network simulation in two states. In the first case, the activity of each neuron was spontaneous, while the second used cycles of excitation and inhibition. Synchronization (simultaneous neuron activity) with the ordered temporal structure (excitation-inhibition cycles, which started simultaneously) was significantly greater than in conditions of spontaneous activity and when cycles started non-simultaneously. These results show that synchronization in local neural networks is increased mainly because of transient inhibition and that the greater amplitude of the summed (field) potential may reflect the synchronous operation of nervous system elements which are not directly connected to each other.

THE SMOOTH MUSCLE CONTRACTING ACTION OF EFFLUENTS FROM THE ISOLATED GUINEA PIG ILEUM

AbstractAn analysis was made of the effect of effluents from both outside and inside of the isolated guinea pig ileum segments. The action of the outside effluents was directed towards nervous elements of the test segment of the isolated ileum. According to the effect of atropine, morphine and hexamethonium, the action of theeffluent resembled that of 5-HT. Atropine and antazoline did not inhibit the effect of the effluent obtained from the inside of the donor gut upon the isolated rat fundus, but BOL and LSD did so in most experiments. The effect of this effluent upon the test segment of the guinea pig ileum was inhibited by morphine, or by a previous desensitation of the preparation by large doses of 5-HT. The smooth muscle stimulating effect of the effluent probably was due to its content in 5-HT and at least partly to some other as yet unidentified substance(s).

Synovial sarcoma of nerve

Tumors of peripheral nerve are largely neuroectodermal in nature and derived from 2 elements of nerve, Schwann or perineurial cells. In contrast, mesenchymal tumors affecting peripheral nerve are rare and are derived mainly from epineurial connective tissue. The spectrum of the latter is broad and includes lipoma, vascular neoplasms, hematopoietic tumors, and even meningioma. Of malignant peripheral nerve neoplasms, the vast majority are primary peripheral nerve sheath tumors. Malignancies of mesenchymal type are much less common. To date, only 12 cases of synovial sarcoma of nerve have been described. Whereas in the past, parallels were drawn between synovial sarcoma and malignant glandular schwannoma, an uncommon form of malignant peripheral nerve sheath tumor, molecular genetics have since clarified the distinction. Herein, we report 10 additional examples of molecularly confirmed synovial sarcoma, all arising within minor or major nerves. Affecting 7 female and 3 male patients, 4 tumors occurred in pediatric patients. Clinically and radiologically, most lesions were initially thought to be benign nerve sheath tumors. On reinterpretation of imaging, they were considered indeterminate in nature with some features suspicious for malignancy. Synovial sarcoma of nerve, albeit rare, seems to behave in a manner similar to its more common, soft tissue counterpart. Those affecting nerve have a variable prognosis. Definitive recommendations regarding surgery and adjuvant therapies await additional reports and long-term follow-up. The literature is reviewed and a meta-analysis is performed with respect to clinicopathologic features versus outcome.

Intraocular Neuromuscular Choristoma: A Case Report and Literature Review

Neuromuscular choristomas (NMCs) are rare benign tumors of the peripheral nerves. Although histopathological characteristics of this unusual lesion have been recognized, in this regard, neuroimaging findings have not been well described previously. We report the first intraconally located NMC affecting the oculomotor nerve, with histopathological and radiological characteristics. A 10-year-old girl presented with sudden-onset left temporal and retro-orbital pain. Magnetic resonance imaging scans demonstrated a small, capsulated, retro-orbital, intraconal solid lesion that was diagnosed as an atypical dermoid cyst preoperatively. The tumor was resected subtotally. Postoperatively, the patient became pain free, but ipsilateral ptosis and upward eye movement failure developed. Histologically, the lesion consisted of well-differentiated striated muscle fibers intermingled with mature nerve elements consistent with the NMC. Although intracranial NMCs need histological confirmation for diagnosis, neuroimaging might contribute to the preoperative diagnosis and management strategy of treatment. We report the first intraconal NMC, which should be considered in the differential diagnosis of intraorbital tumors.