Visualization of the human enteric nervous system by probe confocal laser endomicroscopy: a first real-time observation of Hirschsprung's disease and allied disorders.

BACKGROUND: Our group previously proved that the human enteric nervous system can be visualized with confocal laser endomicroscopy after topical application of cresyl violet using surgically resected intestine specimens. The present report documents the first in vivo visualization of the human enteric nervous system with confocal laser endomicroscopy using local cresyl violet staining. The aim of this study was to evaluate the technical feasibility and clinical efficiency of confocal laser endomicroscopy in patients with Hirschsprung's disease and allied disorders in vivo. METHODS: Confocal laser endomicroscopy was performed in vivo in two patients to confirm the presence of the enteric nervous system during surgery in patients with Hirschsprung's disease and allied disorders. Cresyl violet was gently injected from the serosal side into the muscular layer of the intestine, and scanning was performed within 30 min. Then, the scanned intestines were resected, and the visualized area of the specimens was pathologically evaluated. RESULTS: The ganglion cell nuclei and the enteric nervous system network were clearly visualized intraoperatively in both cases. The morphological findings were similar to the pathological findings of the enteric nervous system in both cases although the period of visibility was brief. CONCLUSION: This study demonstrated the first, real-time observation of the enteric nervous system in humans using confocal laser endomicroscopy and suggest the potential to identify the enteric nervous system intra-operatively during surgery for Hirschsprung's disease and allied disorders.

Prostate-Specific Membrane Antigen Uptake in a Peripheral Nerve and Respective Ganglia on 68Ga-Prostate-Specific Membrane Antigen-HBED-CC PET/CT.

A 74-year-old man with a history of prostate cancer with proven osseous metastatic disease underwent Ga-prostate-specific membrane antigen (PSMA) PET/CT under antiandrogen therapy. The scan revealed a long segment of increased PSMA tracer uptake within the right sciatic nerve, which appeared edematous and swollen, and the respective ganglia. Clinically, the patient suffered from pain and paresis in the right leg. As infiltration of a long segment of a single nerve seems unlikely, primarily neuronal disease such as neuritis (induced by metastases or radiotherapy) was considered. The observed uptake of PSMA-targeting PET tracers may then represent a peripheral nerve disorder.

Peripheral ganglia in healthy rats as target structures for the evaluation of PSMA imaging agents.

BACKGROUND: The recent implementation of PET with prostate specific membrane antigen (PSMA)-specific radiotracers into the clinical practice has resulted in the significant improvement of accuracy in the detection of prostate carcinoma (PCa). PSMA-expression in ganglia has been regarded as an important pitfall in prostate carcinoma-PET diagnostics but has not found any practical use for diagnosis or therapy. METHODS: We explored this phenomenon and demonstrated the applicability of peripheral ganglia in healthy rats as surrogates for small PSMA positive lesions for the preclinical evaluation of diagnostic PCa PET probes. Healthy rats were measured with PET/CT using the tracers [18F]DCFPyL, [Al18F]PSMA-11 and [68Ga]PSMA-11. Sections of ganglia were stained with an anti-PSMA antibody. [18F]DCFPyL uptake in ganglia was compared to that in LNCaP tumor xenografts in mice. RESULTS: Whereas [18F]DCFPyL and [68Ga]PSMA-11 were stable in vivo and accumulated in peripheral ganglia, [Al18F]PSMA-11 suffered from fast in vivo deflourination resulting in high bone uptake. Ganglionic PSMA expression was confirmed by immunohistochemistry. [18F]DCFPyL uptake and signal-to-noise ratio in the superior cervical ganglion was not significantly different from LNCaP xenografts. CONCLUSIONS: Our results demonstrated the non-inferiority of the novel model compared to conventionally used tumor xenografts in immune compromised rodents with regard to reproducibility and stability of the PSMA signal. Furthermore, the model involves less expense and efforts while it is permanently available and avoids tumor-growth associated animal morbidity and distress. To the best of our knowledge, this is the first tumor-free model suitable for the in vivo evaluation of tumor imaging agents.

Optimization of Laser-Capture Microdissection for the Isolation of Enteric Ganglia from Fresh-Frozen Human Tissue.

The purpose of this method is to obtain high-integrity RNA samples from enteric ganglia collected from unfixed, freshly-resected human intestinal tissue using laser capture microdissection (LCM). We have identified five steps in the workflow that are crucial for obtaining RNA isolates from enteric ganglia with sufficiently high quality and quantity for RNA-seq. First, when preparing intestinal tissue, each sample must have all excess liquid removed by blotting prior to flattening the serosa as much as possible across the bottom of large base molds. Samples are then quickly frozen atop a slurry of dry ice and 2-methylbutane. Second, when sectioning the tissue, it is important to position cryomolds so that intestinal sections parallel the full plane of the myenteric plexus, thereby yielding the greatest surface area of enteric ganglia per slide. Third, during LCM, polyethylene napthalate (PEN)-membrane slides offer the greatest speed and flexibility in outlining the non-uniform shapes of enteric ganglia when collecting enteric ganglia. Fourth, for distinct visualization of enteric ganglia within sections, ethanol-compatible dyes, like Cresyl Violet, offer excellent preservation of RNA integrity relative to aqueous dyes. Finally, for the extraction of RNA from captured ganglia, we observed differences between commercial RNA extraction kits that yielded superior RNA quantity and quality, while eliminating DNA contamination. Optimization of these factors in the current protocol greatly accelerates the workflow and yields enteric ganglia samples with exceptional RNA quality and quantity.

3D virtual histology at the host/parasite interface: visualisation of the master manipulator, Dicrocoelium dendriticum, in the brain of its ant host.

Some parasites are able to manipulate the behaviour of their hosts to their own advantage. One of the most well-established textbook examples of host manipulation is that of the trematode Dicrocoelium dendriticum on ants, its second intermediate host. Infected ants harbour encysted metacercariae in the gaster and a non-encysted metacercaria in the suboesophageal ganglion (SOG); however, the mechanisms that D. dendriticum uses to manipulate the ant behaviour remain unknown, partly because of a lack of a proper and direct visualisation of the physical interface between the parasite and the ant brain tissue. Here we provide new insights into the potential mechanisms that this iconic manipulator uses to alter its host's behaviour by characterising the interface between D. dendriticum and the ant tissues with the use of non-invasive micro-CT scanning. For the first time, we show that there is a physical contact between the parasite and the ant brain tissue at the anteriormost part of the SOG, including in a case of multiple brain infection where only the parasite lodged in the most anterior part of the SOG was in contact with the ant brain tissue. We demonstrate the potential of micro-CT to further understand other parasite/host systems in parasitological research.

MRI analysis of extra-capsular ganglia at the gastrocnemius origin and their association with osteoarthritis.

AIM: To evaluate the prevalence, clinical relevance, and magnetic resonance imaging (MRI) features of extra-capsular ganglia at the gastrocnemius origin and to assess their association with internal derangement and osteoarthritis of the knee. MATERIALS AND METHODS: One hundred consecutive knee MRI examinations, obtained within a 6-month period from patients with no history of recent knee trauma, recent injections, inflammatory arthritis, infection, or tumours, were evaluated retrospectively for the presence of ganglia at the gastrocnemius origin. The lesions were divided into two groups: an intra-capsular and an extra-capsular group. Cyst morphology (size, shape, and internal septa), internal derangement of the knee (cartilage lesion, cruciate ligament injury, meniscal tear, and corner injury on MRI, and osteoarthritis of the knee on radiographs) were evaluated. The chi-square, Fisher's exact, and t-tests were used to compare the two groups, in addition to multivariate stepwise logistic regression analysis. RESULTS: Thirty-nine ganglia with an extra-capsular location were identified on 100 knee MRI (39 %). Rounded shape and internal septa were more common in the extra-capsular than in the intra-capsular group (p<0.001). Frequencies of high-grade cartilage, meniscal tear, and high-grade osteoarthritis significantly differed between the groups (p≤0.038). In multivariate analysis, the only significant association was between high-grade osteoarthritis and the extra-capsular group. CONCLUSION: Extra-capsular ganglia at the gastrocnemius origin were not uncommon on knee MRI and had features typical of ganglia found at other sites. High-grade osteoarthritis was significantly associated with extra-capsular ganglia.

Patterns of uptake of prostate-specific membrane antigen (PSMA)-targeted 18F-DCFPyL in peripheral ganglia.

OBJECTIVE: Radiotracers targeting prostate-specific membrane antigen (PSMA) have increasingly been recognized as showing uptake in a number of normal structures, anatomic variants, and non-prostate-cancer pathologies. We aimed to explore the frequency and degree of uptake in peripheral ganglia in patients undergoing PET with the PSMA-targeted agent 18F-DCFPyL. METHODS: A total of 98 patients who underwent 18F-DCFPyL PET/CT imaging were retrospectively analyzed. This included 76 men with prostate cancer (PCa) and 22 patients with renal cell carcinoma (RCC; 13 men, 9 women). Scans were evaluated for uptake in the cervical, stellate, celiac, lumbar and sacral ganglia. Maximum standardized uptake value corrected to body weight (SUVmax), and maximum standardized uptake value corrected to lean body mass (SULmax) were recorded for all ganglia with visible uptake above background. Ganglia-to-background ratios were calculated by dividing the SUVmax and SULmax values by the mean uptake in the ascending aorta (Aortamean) and the right gluteus muscle (Gluteusmean). RESULTS: Overall, 95 of 98 (96.9%) patients demonstrated uptake in at least one of the evaluated peripheral ganglia. With regard to the PCa cohort, the most frequent sites of radiotracer accumulation were lumbar ganglia (55/76, 72.4%), followed by the cervical ganglia (51/76, 67.1%). Bilateral uptake was found in the majority of cases [lumbar 44/55 (80%) and cervical 30/51 (58.8%)]. Additionally, discernible radiotracer uptake was recorded in 50/76 (65.8%) of the analyzed stellate ganglia and in 45/76 (59.2%) of the celiac ganglia, whereas only 5/76 (6.6%) of the sacral ganglia demonstrated 18F-DCFPyL accumulation. Similar findings were observed for patients with RCC, with the most frequent locations of radiotracer uptake in both the lumbar (20/22, 90.9%) and cervical ganglia (19/22, 86.4%). No laterality preference was found in mean PSMA-ligand uptake for either the PCa or RCC cohorts. CONCLUSION: As PSMA-targeted agents become more widely disseminated, the patterns of uptake in structures that are not directly relevant to patients' cancers must be understood. This is the first systematic evaluation of the uptake of 18F-DCFPyL in ganglia demonstrating a general trend with a descending frequency of radiotracer accumulation in lumbar, cervical, stellate, celiac, and sacral ganglia. The underlying biology that leads to variability of PSMA-targeted radiotracers in peripheral ganglia is not currently understood, but may provide opportunities for future research.

Ectopic ganglion in cauda equina: case report.

Macroscopic ectopic or heterotopic ganglionic tissue within the cauda equina is a very rare pathological finding and is usually associated with spinal dysraphism. However, it may mimic genuine neoplasms of the cauda equina. The authors describe a 29-year-old woman with a history of back pain, right leg pain, and urinary incontinence in whom imaging demonstrated an enhancing mass located in the cauda equina at the L1-2 interspace. The patient subsequently underwent biopsy and was found to have a focus of ectopic ganglionic tissue that was 1.3 cm in greatest dimension. To the authors' knowledge, ectopic or heterotopic ganglionic tissue within the cauda equina in a patient without evidence of spinal dysraphism has never been reported. This patient presented with imaging and clinical findings suggestive of a neoplasm, and an open biopsy proved the lesion to be ectopic ganglionic tissue. The authors suggest that ectopic ganglionic tissue be added to the list of differential diagnoses of a space-occupying lesion arising from the cauda equina.

High-resolution sonography of the common peroneal nerve: detection of intraneural ganglia.

We performed sonographic examination of the common peroneal nerve in 41 consecutive patients with a footdrop to determine whether there was a structural lesion of the peroneal nerve. Five of the 28 patients (18%) with an isolated peroneal mononeuropathy had an intraneural ganglion of the peroneal nerve confirmed by histology. High-resolution sonography should be considered in patients with nontraumatic peroneal palsy.

Neuropathy of motor branch of median or ulnar nerve induced by midpalm ganglion.

Two cases of neuropathy of a motor branch caused by a midpalmal ganglion are presented. In the first case the ganglion originated from the midcarpal joint, protruded into the thenar muscle, and compressed the motor branch of the median nerve. In the second case the ganglion, distal to the fibrous arch of the hypothenar muscles, originated from the third carpometacarpal joint and compressed the motor branch of the ulnar nerve. In both cases muscle weakness and finger deformity recovered well after resection of the ganglion. This clinical condition is rare compared with carpal tunnel syndrome and Guyon's tunnel syndrome, which are caused by a ganglion in the wrist.

Sonographic appearances of nerve tumors.

This article reviews the clinical and sonographic features of neurilemoma, neurofibroma, intraneural ganglion, traumatic neuroma, and Morton's neuroma. The sonographic characteristics and location at typical sites are important diagnostic features for nerve tumors.

Ultrasound in acute and chronic knee injury.

This article presents a clinical approach to the role of ultrasound in the assessment of intra-articular and extra-articular knee pathology, including a comprehensive review of both acute and chronic conditions that may affect the tendons, ligaments, and bursae related to the knee joint. A brief review of the ultrasound findings in degenerative and inflammatory arthropathies and some of the more common tumors and masses that may be encountered around the symptomatic knee also has been included. Finally, the limited role of ultrasound in the assessment of the knee menisci and the symptomatic postarthroscopic patient is discussed.

Tarsal tunnel syndrome caused by ganglia.

We describe in 30 feet the occurrence of a tarsal tunnel syndrome caused by a ganglion. The presenting symptom was numbness or pain in the toes and the sole with paraesthesiae in the distribution of the medial plantar nerve in 63% of the patients. Swellings which were not palpable were detected by ultrasonography. Twenty-nine patients were treated by operation. Most ganglia originated from the talocalcaneal joint, and five were associated with a talocalcaneal coalition. The surgical outcome was satisfactory in all patients except one who had a further operation for a recurrence of the ganglion.

Treatment of flexor tendon sheath ganglions using ultrasound imaging.

Forty-one patients with a symptomatic digital mass or swelling of suspected ganglionic origin were examined by ultrasound. Findings were classified into 4 groups: group 1, solitary cyst appearing as a well-defined solitary oval anechoic mass (27 digits); group 2, multiple cysts having multiple oval anechoic masses (3 digits); group 3, solid tumor indicating a heterogeneous hypoechoic mass (6 digits); and group 4, tenosynovitis with no abnormal echoic mass (5 digits). Treatment was determined by lesion classification. In group 1, 26 of the 27 solitary cysts were punctured, and a jellylike material was aspirated from 24 cysts. Postaspiration ultrasound examination revealed that a cyst was still present in 2 cases, and these were excised surgically. In group 2, all the cysts were surgically removed. A ganglion with multiple cysts was confirmed on pathological examination. In group 3, the lesions were removed surgically; among the diagnoses were tendon sheath ganglion, giant-cell tumor of tendon sheath, neurilemmoma, and hemangioma. In group 4, no abnormal masses had appeared at follow-up examination. The 24 patients whose ganglions were treated by aspiration, as well as the 8 patients whose ganglions were excised, were monitored for more than 12 months. None of these 32 patients experienced residual pain or lesion recurrence. These results indicate that ultrasound is useful, in cases in which flexor tendon sheath ganglion are suspected, for assisting in diagnosis and determining whether patients should undergo aspiration or surgical excision.

Intraosseous ganglia of carpal bones.

25 patients with 26 intraosseous ganglia in carpal bones are described, 14 in the scaphoid and 12 in the lunate. In most cases, attention was drawn to the lesion when X-rays were performed after a recent injury to the wrist. Typically, they occurred eccentrically and were surrounded by a radio-dense rim of bone. In a few cases the cortex was breached but never expanded by the lesion. Curettage and bone grafting were performed only if symptoms persisted and no other source for the pain could be found. Most contained the typical jelly-like material also found in soft tissue ganglia and the histology showed an identical structure. A suggested format for the management of these lesions is presented.

Bilateral intraosseous ganglia of the lunate: a case report.

A rare case of bilateral intraosseous ganglia of the lunate is reported. The patient had had 7 months of pain in both wrists and a cystic lesion in both lunates. Curettage and bone grafting resulted in complete relief of pain.

Ganglion of deep peroneal nerve: electrophysiology and CT scan in the diagnosis.

Deep peroneal nerve mononeuropathy is rarely observed in clinical practice. We describe a case in which the syndrome was caused by a clinically not detectable ganglion within the anterior compartment of the leg. Electrophysiological data allowed us to localize the site of the lesion for a correct planning of CT scan. CT scan showed a low density tissue occupying the anterior compartment of the leg and its relationships to muscles, septa, bones and vessels. Electrophysiological data and CT scan utilities are discussed.