Giant presacral schwannoma presenting with constipation: a case report

ABSTRACT: INTRODUCTION: Schwannoma, otherwise known as a neurilemmoma, is a tumor arising from peripheral nerve sheaths. Although commonly noted in association with the eighth cranial nerve as intracranial acoustic neuroma, cases of schwannoma arising in other locations have been reported in the literature. These tumors usually cause symptoms as a result of their mass effect and, since they are benign, encapsulated and non-invasive tumors, complete surgical excision is considered curative. CASE PRESENTATION: We report the case of a 46-year-old Sri Lankan man who presented to our facility with recent onset of difficulty evacuating his bowels. He was noted to have a giant presacral schwannoma on magnetic resonance imaging scan. The mass was surgically excised with improvement of our patient's symptoms. A subsequent histopathological examination confirmed the presence of a benign schwannoma. CONCLUSIONS: Although schwannomas commonly occur in the extremities, a rare case of occurrence in the pelvis is reported here. Due to the limited space in the pelvis, the local mass effect may be the presenting feature of such a lesion and surgical excision is curative.     

Restless Legs Syndrome and lateralized periodic movements due to a spinal schwannoma

We describe a case of Restless Legs Syndrome (RLS) associated to periodic limb movements (PLMs) in a woman with a cervical schwannoma. Neurological examination, laboratory tests, neurography and electromyography were unremarkable. Neuroimaging evidenced a schwannoma at C3 level that compressed the right ventral surface of the medulla. Somatosensory-evoked potentials showed absence of the N13 after right median nerve stimulation and reduction of amplitude of the same component after left nerve stimulation. A video-polysomnography documented PLMs with a marked prevalence of the right-sided movements. We believe that the cervical schwannoma played a role in the pathogenesis of RLS and of lateralized PLMs.

     

Focus: Rare Disease: Prostatic Schwannoma Presenting with Prostate-specific Antigen Elevation: A Case Report

Introduction: Schwannoma of the male genital system is very uncommon and is mostly treated by surgery. However, prostatic schwannoma presenting with elevated prostate-specific antigen (PSA) level and treated conservatively are extremely rare. Case presentation: Herein, we present a rare case of a prostatic schwannoma in a 65-year-old man who initially presented with an elevated PSA level. Digital rectal examination revealed an enlarged prostate with a palpable hard nodule on the left side. Transrectal ultrasonography revealed an enlarged prostate with a well-defined homogeneously hypoechoic nodule in the left peripheral lobe. Biopsy was done, and histopathology revealed a prostatic schwannoma. Conservative treatment with regular image follow-up was done per the patient’s preference. Mild PSA progression but no worsening of symptoms was found in 6 years of follow-up. Conclusions: PSA elevation could be a rare presentation of prostatic schwannoma. Treatment options other than surgery, such as conservative treatment with close observation, could be feasible for these rare tumors and long-term survivorship can be achieved.     

A giant plexiform schwannoma of the brachial plexus: case report

We report the case of a patient who noticed muscle weakness in his left arm 5 years earlier. On examination, a biloculate mass was observed in the left supraclavicular area, and Tinel's sign caused paresthesia in his left arm. Magnetic resonance imaging showed a continuous, multinodular, plexiform tumor from the left C5 to C7 nerve root along the course of the brachial plexus to the left brachia. Tumor excision was attempted. The median and musculocutaneous nerves were extremely enlarged by the tumor, which was approximately 40 cm in length, and showed no response to electric stimulation. We resected a part of the musculocutaneous nerve for biopsy and performed latissimus dorsi muscle transposition in order to repair elbow flexion. Morphologically, the tumor consisted of typical Antoni A areas, and immunohistochemistry revealed a Schwann cell origin of the tumor cells moreover, there was no sign of axon differentiation in the tumor. Therefore, the final diagnosis of plexiform Schwannoma was confirmed.     

Retroperitoneal Ancient Schwannoma: A Case Report

Schwannomas are extremely rare tumors that are composed of Schwann cells. Retroperitoneal localization comprises 0.7% to 2.6% of all schwannomas. Patients usually present with nonspecific symptoms. There are no pathognomonic features on radiologic evaluation. Preoperative biopsy is not recommended because of complication risks; however, surgery is necessary for diagnosis and treatment. Although most schwannomas are benign tumors, those that are associated with von Recklinghausen disease are malignant. Schwannomas exhibit regions of high and low cellularity, termed Antoni A and Antoni B areas, with a diffuse positivity of S100 protein on pathologic evaluation. If there are degenerative changes, such as cyst formation, hemorrhage, calcification, and hyalinization, these tumors are termed ancient schwannomas. We present a case of retroperitoneal ancient schwannoma.Key words: Retroperitoneal schwannoma, Neurilemmoma, Schwannoma, Retroperitoneal tumor, RetroperitoneumA schwannoma is a tumor of the Schwann cell or nerve cell sheath.¹ This tumor may occur anywhere there is a nerve with Schwann cells— predominantly in the head and neck region, or flexor surfaces of the extremities. Most schwannomas are benign tumors²; however, malignant schwannomas may be associated with von Recklinghausen disease.³ Retroperitoneal schwannomas are usually larger than those in other sites, and have a greater tendency to undergo spontaneous degeneration and hemorrhage when compared with head, neck, and extremity locations.⁴ We present a case of a retroperitoneal schwannoma that was reported to be an ancient schwannoma on pathologic evaluation.     

Fine needle aspiration cytology of malignant schwannoma metastatic to the breast

A case of malignant schwannoma metastatic to the breast is reported. The tumor was found as a solitary breast lump in a 43-year-old woman and was clinically considered to be a primary tumor. Fine needle aspiration (FNA) smears of the mass were interpreted cytologically as a malignant neurogenic tumor, compatible with a malignant schwannoma. The patient did not have multiple neurofibromatoses. Eight months previously, an excision of a solitary nodule located in the left axilla had been performed in another hospital. Comparison of the histologic section from that excision with the FNA confirmed that the breast tumor was a metastatic malignant schwannoma, and the patient was treated accordingly.     

Case report: schwannoma arising from the unilateral adrenal area with bilateral hyperaldosteronism

Background

We report a rare case of a juxta-adrenal schwannoma that could not be discriminated from an adrenal tumor before surgical resection and was complicated by bilateral hyperaldosteronism. To the best of our knowledge, this is first case in which both a juxta-adrenal schwannoma and hyperaldosteronism co-existed.

Case presentation

A 69-year-old male treated for hypertension was found to have a left supra-renal mass (5.8?×?5.2 cm) by abdominal computed tomography. His laboratory data showed that his plasma aldosterone concentration (PAC) was within the normal range, but his plasma renin activity (PRA) was reduced, resulting in an increased aldosterone/renin ratio (ARR). Load tests of captopril or furosemide in the standing position demonstrated autonomous aldosterone secretion and renin suppression. Adrenal venous sampling (AVS) with ACTH stimulation indicated bilateral hypersecretion of aldosterone. A left supra-renal tumor was resected because of the possibility of malignancy and was found to be a benign schwannoma arising from the juxta-adrenal region together with an adrenal gland. The dissected left adrenal gland was morphologically hyperplastic in the zona glomerulosa, but was immunohistochemically negative for CYP11B2 (aldosterone synthase). Multiple CYP11B2-positive adrenocortical micronodules were detected in the adrenal gland, indicating micronodular hyperplasia. Although bilateral aldosteronism was indicated by AVS before the operation, the PRA, PAC and ARR values were within their respective reference ranges after resection of the unilateral tumor, suggesting that the slight increase in hormone secretion from the remaining right-sided lesion could not be detected after resection.

Conclusion

A clinical and morphologic diagnosis of juxta-adrenal schwannoma is difficult, particularly in a case of hyperaldosteronism, as shown in this case. These data suggest the complexity and difficulty diagnosing adrenal incidentaloma.

     

Intramuscular Sparganosis in the Gastrocnemius Muscle: A Case Report

Sparganosis is a parasitic infection caused by the plerocercoid tapeworm larva of the genus Spirometra. Although the destination of the larva is often a tissue or muscle in the chest, abdominal wall, extremities, eyes, brain, urinary tract, spinal canal, and scrotum, intramuscular sparganosis is uncommon and therefore is difficult to distinguish from a soft tissue tumor. We report a case of intramuscular sparganosis involving the gastrocnemius muscle in an elderly patient who was diagnosed using ultrasonography and MRI and treated by surgical excision. At approximately 1 cm near the schwannoma at the right distal sciatic nerve, several spargana worms were detected and removed.     

The pathobiologic spectrum of Schwannomas

In terms of their morphology, clinical associations and behavior, peripheral nerve sheath tumors are among the most varied of human neoplasm. Not surprisingly, such tumors are subject to frequent misdiagnosis. This is particularly true of the spectrum of schwannomas which include: a) conventional schwannoma, a histologically benign tumor which, on occasion, is destructive of surrounding osseous structures, b) the relatively recently described cellular schwannoma, a tumor that histologically simulates malignant peripheral nerve sheath tumor (MPNST), c) plexiform schwannoma which, particularly in cellular form and when occurring in childhood, simulates MPNST, and d) melanotic schwannoma which is often mistaken for melanoma. The psammomatous form of the latter is often associated with Carney complex, a rare heritable disorder that: a) includes cutaneous lentigines, b) myxomas of skin, subcutaneous tissue, and heart, c) and endocrine neoplasms. The tendency to misdiagnose schwannomas and to overestimate their grade makes schwannomas worthy of note. Herein, we discuss the four major schwannoma variants, their essential clinicopathologic features, and differential diagnosis. The distinction from MPNST is given particular attention.     

The Neurofibromatosis Type 2 Gene Product, merlin, Reverses the F-Actin Cytoskeletal Defects in Primary Human Schwannoma Cells

Schwannoma tumors, which occur sporadically and in patients with neurofibromatosis, account for 8% of intracranial tumors and can only be treated by surgical removal. Most schwannomas have biallelic mutations in the NF2 tumor suppressor gene. We previously showed that schwannoma-derived Schwann cells exhibit membrane ruffling and aberrant cell spreading when plated onto laminin, indicative of fundamental F-actin cytoskeletal defects. Here we expand these observations to a large group of sporadic and NF2-related tumors and extend them to schwannomatosis-derived tumors. Mutation at NF2 correlated with F-actin abnormalities, but the extent of morphological change did not correlate with the type of NF2 mutation. We used a recently described molecular strategy, TAT-mediated protein transfer, to acutely introduce the NF2 protein, merlin, into primary human schwannoma cells in an attempt to reverse the cytoskeletal phenotype. Abnormal ruffling and cell spreading by cells with identified NF2 mutations were rapidly reversed by introduction of TAT-merlin. The effect is specific to TAT-merlin isoform 1, the growth-suppressive isoform of merlin. TAT-merlin isoform 2, a TAT-merlin mutant (L64P), and merlin lacking TAT were ineffective in reversing the cytoskeletal phenotype. Results show that merlin isoform 1 is sufficient to restore normal actin organization in NF2-deficient human tumor cells, demonstrating a key role for merlin in the NF2 phenotype. These results lay the foundation for epigenetic complementation studies in NF2 mouse models and possibly for experiments to evaluate the utility of merlin transduction into patients as protein therapy.     

Anomalous origin of the left coronary artery from the pulmonary artery treated by palliative Vineberg operation in an infant

Anomalous origin of the left coronary artery from the pulmonary artery was diagnosed in an infant girl who had evidence of transmural myocardial infarction of the free wall of the left ventricle. At age 13 months, she underwent a palliative left Vineberg implant, and remained asymptomatic until she was 8 years of age. At that time, she underwent suturing of the left coronary ostium for obliteration of the left coronary shunt at the pulmonary artery. At age 13, she underwent aortocoronary bypass to the left main coronary artery, with end-to-end anastomosis. The patient remains asymptomatic to date. We believe that this is the first reported case of a Vineberg operation performed in an infant for palliation of an anomalous left coronary artery originating from the pulmonary artery. This method allows time for the development of collateral circulation to the left coronary artery before definitive surgery is performed.     

Salivary Gland Tumors and Sialadenitis in Children—Experience at Childrens Hospital of Los Angeles

Parotitis, hemangio-endothelioma and mixed tumors are the most common salivary gland lesions in the pediatric age group. Carcinoma and sarcoma are uncommon. Rapid growth of a tumor and pain suggest malignant change.A conservative non-operative approach is stressed for most cases of chronic parotitis. Scout x-ray films and sialangiographic examination are useful in differentiating an inflammatory lesion from a neoplastic growth. Total parotidectomy is advised if operation is indicated.A case of spontaneous resolution of a hemangioma of the parotid gland is presented. A less aggressive temporizing plan should be considered with these lesions, as the risk of seventh nerve injury in children is considerable.The treatment of choice for a non-inflammatory tumor is surgical excision, for most parotid tumors are radioresistant. Small masses should be completely excised for pathological evaluation. Incisional biopsy may occasionally be indicated in the case of a large diffuse lesion, for it may be inflammatory and total excision unnecessary. Most patients with chronic parotitis came to medical attention because of a non-tender asymptomatic parotid lump or diffuse swelling.     

Facial diplegia with hyperreflexia-a mild Guillain-Barre Syndrome variant, to treat or not to treat?

Schwannomas are common, benign nerve tumors originating from the sheath of peripheral nerves. In this article, a 54 year old woman suffered from sudden onset motor and sensory deficit at her first radial three fingers on her right hand. Radiological investigations were normal. Electromyography diagnosed a median nerve entrapment neuropathy and urgent surgery was performed. Interestingly, a hemorrhaged mass was detected in the median nevre at the proximal end of the carpal ligament and was resected totally. Histopathological diagnosis was Schwannoma. The patient maintained a healthy status for five years.     

Palatal schwannoma in an elderly woman

Schwannoma also known as neurilemmoma is a benign tumour derived from schwann cells and is relatively rare in occurrence. Only 1% of the schwannomas in the head and neck region occur at intra-oral sites. Schwannomas usually occur during the third or fourth decades of life and the tongue is the most common intra-oral site. A case of intra-oral schwannoma in a 70-year-old female in the region of hard palate is described which is extremely rare.     

Comparative anatomical study of the autonomic cardiac nervous system in macaque monkeys

The main aim of this study was to clarify the general morphology of the autonomic cardiac nervous system in macaque monkeys. A submacroscopic comparative anatomical study of the autonomic cardiac nervous system was performed by examining 22 sides of 11 bodies of four species of macaque monkeys, including some previously unreported species (pig-tailed and stump-tailed monkeys), under a surgical stereomicroscope. The following results were obtained. 1) The basic arrangement of the autonomic cardiac nervous system is constant in all examined macaques. 2) A superior cardiac nerve originating from the superior cervical ganglion was not observed, whereas the thoracic cardiac nerve originating from the sympathetic trunk/ganglia under the cervicothoracic ganglion was rarely observed in all the examined macaques. 3) The main cardiac nerve is the middle cardiac nerve originating from the middle cervical ganglion, similar to the situation in humans. 4) Although the superior, inferior, and thoracic cardiac branches of the vagus nerve were consistently observed, the left thoracic cardiac branch is rarely absent because of its lower origin to the heart. 5) The cranial autonomic nerves tend to distribute into the heart medially (arterial porta), and the caudal autonomic nerves tend to distribute into the heart laterally (venous porta). To comprehend the comparative morphological and evolutionary changes more completely, these results were compared with our previous studies and some references. Consequently, differences in the sympathetic cardiac nerves of macaques and humans are recognized, in spite of the similar morphologies of the vagal cardiac branches. These differences include the composition of the cervicothoracic ganglion, the lower positions of the middle cervical and cervicothoracic ganglia, and the narrow range for the origin of the cardiac nerves in macaques compared to that in humans.     

Repeat single-fraction stereotactic radiosurgery for recurrent vestibular schwannoma

BackgroundData are scarce on the efficacy of a second radiosurgery (SRS) treatment of vestibular schwannoma that has progressed following initial treatment with SRS. We sought to report the outcome of our repeat SRS series with long-term imaging follow-up.Materials and methodsWe retrospectively analyzed 6 patients who met the following criteria: Repeat SRS at our institution between 1995 and 2018; solitary unilateral tumor; no evidence of neurofibromatosis; and magnetic resonance (MR) planning for both SRS treatments. All treatments were delivered with a linear accelerator-based system using head frame immobilization. The prescribed dose to the periphery of the tumor was 12.5 Gy in all initial and repeat SRS treatments, except for one repeat treatment to 10 Gy.ResultsFollow-up with MR scan following the second SRS treatment was a median 8.4 years. The tumor control rate (lack of progression) following the second SRS treatment was 83% (5/6). Actuarial 10-year outcomes following repeat SRS were: tumor control, 80%; absolute survival, 80%; and cause-specific survival, 100%. Of the patients with at least minimal hearing retention before initial SRS, none had ipsilateral hearing preservation after initial radiation treatment. Improvement in any pretreatment cranial nerve deficits was not seen. The only permanent grade ≥ 3 toxicity from repeat SRS was a case of infraorbital nerve deficit. No patient developed a stroke, malignant transformation, induced second tumor, or facial nerve deficit.ConclusionThere was excellent overall survival, tumor control, and low morbidity in our series for recurrent vestibular schwannoma submitted to repeat single-fraction SRS, supporting additional studies of this treatment strategy.     

Ultrastructural diagnosis of facial nerve schwannoma using fine needle aspiration

In a 14-year-old boy presenting with left facial nerve paralysis, physical examination revealed a soft, round mass in the floor of the left external auditory canal. A fine needle aspiration biopsy was performed to obtain material for light and electron microscopy. Several small groups of uniform, spindle-shaped neoplastic cells were present on the slides; a malignant mesenchymal tumor was considered, but a definite diagnosis could not be established under light microscopy. The ultrastructural examination revealed spindle-shaped and stellate cells with multiple parallel cytoplasmic processes lined with a well-developed basal lamina; these features are highly characteristic of a benign schwannoma.     

Lung function in diaphragm pacing.

Electric stimulation of the diaphragm via the phrenic nerve to induce ventilation has recently been used for the long-term management of chronic ventilatory insufficiency. Since 1973 three patients with inadequate alveolar ventilation have been treated with diaphragm pacing at the Toronto Western Hospital. Two, who had quadriplegia due to lesions of the spinal cord in the upper cervical region and a severe restrictive ventilatory defect, were treated with continuous diaphragm pacing. The third patient required assisted nocturnal ventilation because of primary alveolar hypoventilation. All three patients tolerated the diaphragm pacing well, and pulmonary function tests showed satisfactory gas exchange with the patients breathing room air. This form of therapy seems to be a practical clinical method of managing chronic ventilatory failure in patients with lesions of the upper cervical cord or primary alveolar hypoventilation.     

Tailgut cyst associated with a carcinoid tumor: case report and review of the literature

We report the case of a 49-year-old woman who presented a tailgut cyst lined by a variety of epithelium including squamous, columnar and transitional. Fortuitously a microscopic carcinoid tumor expressing immunohistochemically neuroendocrine markers was identified in the cystic wall. Tailgut cysts are congenital abnormalities located in the presacrococcygeal area occurring usually in adult patients. Clinical diagnosis is difficult because they are often asymptomatic. Patients may present symptoms resulting from local mass effects or complications. The differential diagnoses include rectal duplication cysts, cystic sacrococcygeal teratomas, epidermal cysts, epidermoid cysts, anal duct or gland cysts. Magnetic resonance imaging has recently become the modality of choice to image the cyst. Malignant transformation is rare; 23 cases including 10 carcinoid tumors have been reported in the literature. To our knowledge, this is the eleventh case of carcinoid tumor arising in a tailgut cyst.