Intra-cerebellar schwannoma with various degenerative changes: a case report and a systematic review

Upper thoracic spinal schwannoma leading to intracranial hypertension and hydrocephalus: A case report and literature review

RATIONALE

Hydrocephalus is predominantly caused by intracranial hemorrhage, infections, tumors, genetic metabolic disorders, and congenital malformations. Hydrocephalus secondary to spinal cord tumors is exceedingly rare; these tumors are predominantly located in the upper cervical spinal region or near the conus medullaris. Hydrocephalus and elevated intracranial pressure caused by upper thoracic spinal schwannomas have not previously been reported.

PATIENT CONCERNS

We report the first case in a 71-year-old female patient who presented with bilateral lower limb weakness for 6 months, accompanied by headache, dizziness, and urinary incontinence for 1 month.

DIAGNOSES

This patient was diagnosed with schwannomas located in the upper cervical spinal region.

INTERVENTIONS

Based on preoperative examination results, it was difficult to distinguish a schwannoma from a spinal meningioma. Subsequently, a microsurgical operation was performed, and the whole tumor was removed via a posterior approach. Tumor tissue histopathological results revealed a whole capsule; under a light microscope, the tumor mainly consisted of sheath cells, which were arranged in a palisade or swirl shape. Antoni A and Antoni B regions constituted a large part of the whole tumor. Moreover, cytologic atypia and necrosis or mitosis were absent. Immunohistochemical staining revealed strong positivity staining for S-100 and SOX 10. Hence, a histopathological diagnosis of schwannomas was finally confirmed. The patient's symptoms of intracranial hypertension, hydrocephalus, and spinal cord dysfunction were significantly alleviated after the operation.

OUTCOMES

Follow-up magnetic resonance image (1 month after being discharged from the hospital) of the thoracic spine and brain revealed complete resection of the upper thoracic spinal schwannoma, a significant reduction in the size of ventricles, and marked alleviation of periventricular interstitial edema.

LESSONS

The findings emphasize the importance of considering spinal tumors in cases of unexplained hydrocephalus and may guide early microsurgical intervention.

MRI findings for the pretreatment diagnosis of small Meckel's cave tumors: comparison of meningiomas and schwannomas

BACKGROUND

Both meningiomas and schwannomas are the most common Meckel's cave (MC) tumors in terms of distinct imaging features. When they are small, they may present with similar imaging characteristics that make their diagnosis difficult. The aim of this study was to diagnose small meningiomas and schwannomas of the MC on the basis of their clinical and MRI findings.

METHODS

The clinical data of 33 patients who were diagnosed with small MC tumors (SMCTs) (17 schwannomas, 16 meningiomas) between August 2002 and August 2023 were retrospectively evaluated. SMCTs were defined as MC tumors that were less than 3 cm in size. We analyzed their clinical and MRI findings, including demographic features, lesion morphologies and changes in adjacent structures.

RESULTS

The rate of subtotal resection of meningiomas less than 3 cm in size was significantly lower than that of schwannomas less than 3 cm in size (43.8% vs. 100%, p = 0.032). The MRI features of meningiomas and schwannomas were as follows: 1) a prominent dura tail sign (8/16 [50%] vs. 0/17 [0%], p < 0.001); 2) few cystic components (0/16 [0%] vs. 9/17 [52.94%], p < 0.001); 3) lower minimum ADC (ADCmin) values (820.575 ± 302.545 [86.1-1144.4] vs. 1372.424 ± 561.337 [355.7-2616.6], p < 0.001); and 4) minimal ipsilateral masticatory muscle atrophy (-6.71% ± 22.43% [-85.71% ~ 13.79%] vs. 11.24% ± 11.98% [-14% ~ 38%], p < 0.001). Very small MC tumors (VSMCTs) were ≤ 2 cm in size, and the subgroup analysis of very small meningiomas and schwannomas revealed no differences in terms of ipsilateral masticatory muscle atrophy (p = 0.078), prominence of the dural tail (p = 0.236), or the presence of cystic components (p = 0. 364). However, the ADCmin values were significantly lower for very small meningiomas than for very small schwannomas (p = 0.009).

CONCLUSION

MRI features such as a prominent dural tail appearance, the presence of fewer cystic components, and less masticatory muscle atrophy may aid in differentiating meningiomas from schwannomas less than 3 cm in size. The ADC and DWI parameters provided additional critical insights, particularly for VSMCTs, thus facilitating preoperative diagnoses.

A Rare Presentation of Intracerebellar Schwannoma: A Case Report

Background: Intracerebellar schwannoma is an extremely rare disease entity with only 21 case reports described in the literature. Case Description: A 68-year-old male presented with chronic headaches, dizziness, gait imbalance, and incoordination. Previous MRI had revealed a cystic lesion in the right cerebellum; however, patient was lost to follow-up. Updated MRI revealed dramatic enlargement of the lesion in addition to worsening clinical status. The patient underwent successful surgical resection. Conclusion: Intracerebellar schwannoma can be challenging to diagnose preoperatively due to its rare occurrence; however, it should be included in the differential diagnosis of cystic lesions in the cerebellum, and most cases can be successfully treated with complete surgical resection. Pathological examination revealed a spindle cell neoplasm with other typical histopathological features of schwannoma.

Clinical and radiological features of intracranial ancient schwannomas: a single-institution, retrospective analysis

Ancient schwannoma (AS) is a subtype of schwannoma characterized by slow progression despite degenerative changes in pathology. Although it is considered a benign tumor, most previous reports have focused on extracranial AS; therefore, the clinical characteristics of intracranial AS is not clear. We included 174 patients who underwent surgery for sporadic intracranial schwannoma, and 13 patients (7.5%) were diagnosed with AS. Cysts were significantly more common in patients with AS than conventional schwannomas (92.3% vs. 44.7%, p < 0.001), as was bleeding (38.5% vs. 6.9%, p = 0.003) and calcification (15.4% vs. 1.3%, p = 0.029). The maximum tumor diameter was also larger in patients with AS (35 mm vs. 29 mm, p = 0.017). The median duration from symptom onset to surgery (7.0 vs. 12.5 months, p = 0.740) did not significantly differ between groups, nor did the probability of postoperative recurrence (p = 0.949). Intracranial AS was strongly associated with cyst formation and exhibited a benign clinical course with a lower rate of recurrence and need for salvage treatment. Extracranial AS is reportedly characterized by a slow progression through a long-term clinical course, whereas intracranial AS did not progress slowly in our study and exhibited different clinical features to those reported for extracranial AS.

Case Report: Adrenal glands degenerated schwannoma: Report of three cases and literature review

Background

Schwannoma is a benign tumor, of which degenerated schwannoma is a subtype. Retroperitoneal schwannomas are extremely rare, as they account for only 3% of retroperitoneal tumors.Degenerated schwannoma is a schwannoma subtype. However,degenerated schwannoma occurring in the adrenal glands is extremely rare.

Case summary

Case 1: A 42-year-old man was referred to our hospital for further examination of a left adrenal mass that was incidentally discovered during a routine physical check-up.No significant abnormalities were found in laboratory tests results. Robotic-assisted laparoscopic excision of the left adrenal gland was performed under general anesthesia. Case 2: A 47-year-old man was admitted to the hospital because of a left adrenal mass found on a routine physical examination.The patient was previously in good health, and there was no family history of a similar disorder. Left-sided laparoscopic adrenalectomy was performed under general anaesthesia. Case 3: A 62-year-old woman with hypertension and diabetes mellitus was referred to our hospital after an incidentally found left adrenal mass.There was no family history of a similar disorder. Left-sided laparoscopic adrenalectomy was performed under general anaesthesia. None of the patients had a recurrence in our study during the postoperative follow-up.

Conclusion

Degenerated schwannoma of the adrenal glands is very rare. The clinical presentations of degenerated schwannoma are nonspecific; a small number of patients do not have any symptoms, and the mass is only found incidentally during physical examination for any number of reasons. The preoperative diagnosis of adrenal degenerated schwannoma is difficult because the diagnosis must rely on pathological examination and immunohistochemistry assays. The management is surgical excision and regular follow-up.