Synovial sarcoma of the tibial nerve - case report of a rare tumor in a rare location requiring early diagnosis.

BACKGROUND: We present the case of a patient with a rare synovial sarcoma (SS) of the tibial nerve. So far, only 4 cases of patients with SS originating from the tibial nerve have been described in the literature, and our patient is only the second patient whose limb was saved during treatment. Synovial sarcomas are malignant mesenchymal tumors, i.e., tumors arising from connective tissue. Synovial sarcomas account for 5-10% of all soft tissue sarcomas. However, the name synovial sarcoma is misleading, because the tumor does not originate from synovial cells, but rather from primitive mesenchymal cells. The name most likely originated from the localization around the large joints on the limbs, more often on the lower ones, in the area of the knee joints. We point out the aspects of correct and quick diagnosis and subsequent treatment, which has very important effect on the patient's prognosis. Primary less radical excision without prior biopsy verification leads to a higher risk of local recurrence, even if a proper reexcision was performed immediately after biopsy verification of the sarcoma. CASE PRESENTATION: A woman born in 1949 began to suffer at the end of 2020 with escalating pain under the left inner ankle with a projection to the sole and fingers. Her personal, family work and social history were insignificant. After the initial neurological examination, the patient was sent for an ultrasound examination of the ankle, which showed a lobular mass measuring 50 × 22 × 16 mm and according magnetic resonance imaging, the finding appeared to be a suspicious neurinoma of the tibial nerve. The tumor was surgically excised, without prior biopsy verification: a 50 × 20 mm tumor was dissected in the distal part of the tarsal canal, which grew through the structure of the tibial nerve and in some places into the surrounding area and appeared intraoperatively as a neurofibroma. But histologically the tumor was classified as monophasic synovial sarcoma. The patient was indicated for a wide reexcision of the skin with the subcutaneous tissue of size 91 × 20 × 15 mm. Now the patient is being treated with external radiotherapy to the tumor bed and she is able to walk. CONCLUSION: This report draws attention to a rare type of malignant nerve tumor, which both clinically and radiologically can mimic benign peripheral nerve sheath tumors. Synovial sarcoma should be considered in very painful resistances, typically located around the joints of the lower limbs, the growth of which can be slow. Because the size of the tumor is a negative prognostic factor, it is necessary to make a timely diagnosis using MR imaging and a biopsy with histological examination and to start treatment quickly. Surgical treatment should take place only after a biopsy with histological examination of the tumor so that it is sufficiently radical and does not have to undergo an additional reoperation, as happened in the case of our patient.

Cauda equina neuroendocrine tumors show biological features distinct from other paragangliomas and visceral neuroendocrine tumors.

Cauda equina neuroendocrine tumors (CENETs) are neoplasms of uncertain histogenesis with overlapping features between those of paragangliomas (PGs) and visceral neuroendocrine tumors (NETs). We have explored their biological relationship to both subsets of neuroendocrine neoplasms. The clinical and radiological features of a cohort of 23 CENETs were analyzed. A total of 21 cases were included in tissue microarrays, along with a control group of 38 PGs and 83 NETs. An extensive panel of antibodies was used to assess epithelial phenotype (cytokeratins, E-cadherin, EpCAM, Claudin-4, EMA, CD138), neuronal and neuroendocrine features (synaptophysin, chromogranin A, INSM1, neurofilaments, NeuN, internexin-α, calretinin), chromaffin differentiation (GATA3, Phox2b, tyrosine hydroxylase), and possible histogenesis (Sox2, T-brachyury, Oct3/4, Sox10). The cohort included 5 women (22%) and 18 men (78%). The average age at the time of surgery was 48.3 years (range from 21 to 80 years). The average diameter of the tumors was 39.27 mm, and invasion of surrounding structures was observed in 6/21 (29%) tumors. Follow-up was available in 16 patients (median 46.5 months). One tumor recurred after 19 months. No metastatic behavior and no endocrine activity were observed. Compared to control groups, CENETs lacked expression of epithelial adhesion molecules (EpCAM, CD138, E-cadherin, Claudin-4), and at the same time, they lacked features of chromaffin differentiation (GATA3, Phox2b, tyrosine hydroxylase). We observed no loss of SDHB. Cytokeratin expression was present in all CENETs. All the CENETs showed variable cytoplasmic expression of T-brachyury and limited nuclear expression of Sox2. These findings support the unique nature of the neoplasm with respect to NETs and PGs.

Effect of antibiotic therapy on proton MR spectroscopy findings in human pyogenic brain abscesses.

BACKGROUND: This work aims to determine how antibiotic therapy influences MR spectroscopic findings in patients undergoing treatment for pyogenic brain abscess. METHODS: This prospective, single center study included all patients who received treatment for brain abscesses at the Neurosurgery Department of University Hospital Ostrava between 2012-2017. Preoperative MR imaging was carried out on all patients including diffusion-weighted imaging and in vivo single-voxel proton spectroscopy with intermediate echo time. The following factors were evaluated: duration of antibiotic therapy, characteristics of MR imaging and spectra findings and culture results. RESULTS: MR spectroscopy findings characteristic of brain abscesses, i.e. the resonances of at least one of the metabolites concerned (amino acids, acetate, alanine and succinate), were observed in 23 patients who had undergone antibiotic therapy for less than 72 hours beforehand (median 7 hours; IQR 30 hours). The 20 patients who underwent antibiotic therapy for longer than this (the median time was 336 hours with an IQR of 284 hours) showed no abscess-specific metabolites, only nonspecific lactate and/or lipid resonance (P<0.0005). These results were further compared with culture findings of pus samples taken intraoperatively: a significantly higher rate of positive culture (78.2%) was determined in cases where antibiotics were administered less than 72 hours before MRS (P<0.0005). CONCLUSIONS: Prolonged antibiotic therapy can influence MRS findings in pyogenic brain abscesses - a fact which is certainly necessary to take into account in its differential diagnosis. The disappearance of the characteristic metabolites can be indirectly interpreted as an indicator of successful antibiotic therapy in cases where surgical intervention is not possible. Further study in this field is required to confirm the results of this study.

A rare case of non-traumatic spinal epidural hematoma in lumbar region associated with apixaban therapy.

Spontaneous spinal epidural hematoma (SSEH) is a very rare clinical entity with potential diagnostic difficulties and which can result in severe neurological deficit. The etiology of this rare condition is largely not known, but with potential predisposition in patients on anticoagulation medication. This includes the novel anticoagulants with direct inhibition of the factor Xa mechanism (DOACs). These medications are supposed to have more predictable pharmacokinetics with fewer severe haemorrhagic adverse events in comparison with standard warfarin therapy. However, in the last few years, an increasing number of case reports have been published of haemorrhage into the central nervous system. We present a case of non-traumatic spinal epidural hematoma in the lumbar region in a patient on chronic apixaban therapy. To the best of our knowledge, it is the first described SSEH in the lumbar region associated with apixaban therapy.

Moyamoya disease associated with fibromuscular dysplasia of intrapulmonary bronchial arteries-a case report.

A case is reported of a 40-year-old woman clinically diagnosed as moyamoya disease with associated fibromuscular dysplasia of intrapulmonary bronchial arteries incidentally revealed during autoptic examination. Moyamoya disease represents an idiopathic noninflammatory and nonatherosclerotic arterio-occlusive process of intracranial arteries. Prolonged brain ischemia leads to formation of tiny and fragile collaterals. Clinically, patients with moyamoya angiopathy commonly present with severe neurological symptoms caused by brain infarction or hemorrhage. Histologically, the steno-occlusive process is based on fibrocellular thickening of intima and intimal smooth muscle cell proliferation. In the literature, extracranial arterial involvement, i.e. fibromuscular dysplasia of renal or pulmonary arteries, has been described in several cases of moyamoya disease. Our aim is to show a unique case of moyamoya disease associated with fibromuscular dysplasia affecting an uncommon site.

Brain abscess and pyocephalus: our experience with treatment.

INTRODUCTION: Pyocephalus always presents serious complications in the treatment of brain abscesses, and is associated with high rates of mortality and morbidity. This study aimed to comprehensively evaluate this understandably feared complication from a purely medical perspective by using an evidence-based approach and drawing comparisons from the available literature, which mostly comprises case reports. METHODS: This was a prospective monocentric study of all patients treated for brain abscesses at the Neurosurgery Clinic of the University Hospital Ostrava between 2012 and 2017. The cohort was divided into two groups for statistical comparison; one group comprised those in which pyocephalus occurred before or during treatment, while the other group comprised patients without this complication. Particular consideration was given to the effect of pyocephalus on morbidity and mortality rates and C-reactive protein levels, as well as to the identification of risk factors, and to its possible therapeutic influence. Patients were followed up for six months. RESULTS: A total of 43 patients were treated for a brain abscess. An unequivocal diagnosis of pyocephalus was established via CT and MRI brain scans in five cases (11.6%). In the cohort as a whole, mortality and morbidity rates were 23.3% and 48.8% respectively. Among patients with pyocephalus the incidence of mortality and morbidity was 40% and 66.6% respectively. The presence of pyocephalus is not a significant predictor of either morbidity (p 0.575) or mortality (p 0.664). In patients with pyocephalus, we determined elevated CRP levels on the day of surgery (p 0.038). The occurrence of epileptic seizures in the acute phase of the disease is associated with a poor outcome (p 0.039). CONCLUSIONS: Pyocephalus will continue to be a serious complication in the treatment of brain abscesses, although we were unable to determine its utility as a prognostic factor. Patients with this complication have elevated CRP levels on the day of operation.

Rare case of a localized radial nerve amyloid neuropathy.

We report the case of a 55-year-old woman with a 6-month history of progressive paresis of the right radial nerve. Perioperative imaging detected a spindle-shaped expansion of the radial nerve caused by an isolated local deposit of amyloid (amyloidoma). The deposit was resected in 2 phases and the resulting defect was bridged by a sural nerve autograft. Overall internal and hematological examination did not reveal systemic amyloidosis or lymphoproliferative disorder. The reason for our report is that localized forms of amyloid neuropathy are very rare.

The potential benefit of intracarpal pressure measurement in endoscopic carpal tunnel syndrome surgery--an analysis of EMG findings and pressure values.

Endoscopic carpal tunnel syndrome surgery is a modern minimally invasive method of carpal tunnel decompression. However, the method does also have its critics, who emphasize that there is an increased rate of complications in comparison to open procedures. To further improve and optimize results of endoscopic surgery we used an intracarpal pressure sensor to verify the effect of carpal tunnel decompression. The endoscopic single portal approach was used in all cases. Median nerve conduction studies were performed prior to and 3 months after surgery. Two groups, those with pressure studies and those without, were then compared according to several EMG parameters such as: median nerve distal motor latency, amplitude of motor response, sensory nerve conduction velocity to the index finger, and amplitude of sensory nerve action potential. In both groups, we observed similarly significant improvements in all conduction parameters, except the amplitude of motor response, which did not change in either group, i.e. no difference in postoperative EMG between the two groups was observed. Despite this fact, intracarpal pressure measurement is still useful in localising the point in which the median nerve is compressed and provides valuable functional information on the level decompression achieved.

The changes of peripheral nerve microstructure after surgical manipulation--experiment on rat model.

The aim of our study was to describe histopathology of the peripheral nerve after its circular release followed by embedding in different environs. We operated on 18 male rats divided into 3 groups. In the first group right femoral nerve was surgically released. In the second group the nerve was enveloped by the subcutaneous fat flap. In the third one the nerve was wrapped up by the skeletal muscle. Six weeks later the animals were killed by exsanguination. The femoral nerve, in the first group, did not show any pathological changes. In the second group 3 animals appeared normal or nearly normal, nevertheless in 3 of them perineural fibrosis and axonal degeneration were observed. Histological reaction in the third group disclosed dispersed axonal injury. Our experiments using rat model imitate situation in humans. The results obtained will help us in making meaningful decision when performing peripheral nerve injury.

[Surgical treatment of brain abscess--retrospective analysis of the group of patients with brain abscess, treated at our department in last 12 years]. / Chirurgická lécba abscesu mozku--retrospektivní analýza souboru nemocných s diagnózou abscesu mozku, lécených na nasem pracovisti za posledních 12 let.

The authors retrospectively evaluated group of patiens treated at the Department of neurosurgery in Hradec Králové from 10/1993 to 10/2004 with the diagnosis of brain abscess. During this period, we treated 23 patients, 15 males and 8 women with the median age 48 years. Patiens with the iatrogenic etiology and those with pyocefalus and subdural and epidural empyema were excluded from this group. We provided 45 surgical procedures with total mortality 17,4 %.

[Indication and radicality of surgical treatment in spinal myeloma]. / Indikace a radikalita chirurgické lécby myelomu v páteri.

In our set of 19 operated patients with spinal myeloma it was in 17 patients (89%) the first manifestation of malignant haematological disease. Indication for admission for surgery were in 18 patients (92%) graphical signs of spinal compression of osteolytic affliction of the vertebra of unclear aetiology, which in 17 (63%) of patients were demonstrated by neurological deficit. On the basis of graphical examinations the most frequent suspicion was on metastatic affliction of the spine at unknown primary focus and the basic diagnosis was determined after the operation at most of cases. In decision about the choice of radicalness of surgery intervention important data about the type of tumour in the spine were usually missing and it especially did not make possible to estimate the life expectation of the patient. When deciding about the radicalness of the surgery, we started from the degree of spinal compression and surgical character of pathological process in the spine. The aim of the operation is to decompress the spinal cord in tumour and to stabilize the afflicted part of the spine. Radical extirpation of tumour followed with stabilization and spine reconstruction we decided to carry out in 7 patients, i.e. 37%, all of them clinically improved and from this group only 2 patients (29%) died till now. We carried out only palliative surgery on the spine in next 12 patients, i.e. in 63%, only 6 patients improved neurologically, i.e. 50% and 10 patients, i.e. 83% died till now.