Brain invasion in meningiomas: does surgical sampling impact specimen characteristics and histology?

Brain invasion (BI) is a new criterion for atypia in meningiomas and therefore potentially impacts adjuvant treatment. However, it remains unclear whether surgical practice and specimen characteristics influence histopathological analyses and the accuracy of detecting BI. Tumor location, specimen characteristics, and rates of BI were compared in meningioma samples obtained from 2938 surgeries in different neurosurgical departments but diagnosed in a single neuropathological institute. Non-skull base tumor location was associated with CNS tissue on the microscopic slides (OR 1.45; p < .001), increasing specimen weight (OR 1.01; p < .001), and remaining tissue not subjected to neuropathological analyses (OR 2.18; p < .001) but not with BI (OR 1.29; p = .199). Specimen weight, rates of residual tissue not subjected to histopathological analyses, of BI and of brain tissue, on the microscopic slides differed among the neurosurgical centers (p < .001, each). Frequency of BI was increased in one department (OR 2.07; p = .002) and tended to be lower in another (OR .61; p = .088). The same centers displayed the highest and lowest rates of brain tissue in the specimen, respectively (p < .001). Moreover, the correlation of BI with the neurosurgical center was not confirmed when only analyzing specimen with evidence of brain tissue in microscopic analyses (p = .223). Detection of BI was not correlated with the intraoperative use of CUSA in subgroup analyses. Rates of brain invasion in neuropathological analyses are not associated with tumor location but differ among some neurosurgical centers. Evidence raises that surgical nuances impact specimen characteristics and therefore the accuracy of the detection of BI.

Frequency of unexpected and important histopathological findings in routine intervertebral disc surgery.

OBJECT: The value of routine histopathological examination of intervertebral disc tissue has been questioned, but sufficient numbers of studies have yet to be conducted to provide a definitive sense of its importance. The aim of this study was to investigate the nature and frequency of unexpected histopathological findings in intervertebral disc surgery. METHODS: The authors conducted a retrospective examination of consecutive surgical specimens obtained in patients with benign indication for discectomy at four neurosurgical centers. Surgical specimens obtained during 2102 operations (2177 intervertebral discs) in 2017 patients were evaluated. In addition to one case of cavernous malformation, two specimens (obtained in 0.1% of patients) revealed unexpected pathological diagnoses of malignancy (metastasized prostate carcinoma and diffuse large B-cell lymphoma). CONCLUSIONS: The results of this retrospective study suggest that routine histopathological examination of specimens obtained during intervertebral disc procedures is both justified and cost effective.

Myopericytoma: A Series of 5 Cases Affecting the Nervous System.

BACKGROUND: Myopericytomas are benign vascular tumors composed of perivascular myoid cells that usually arise in superficial soft tissues of the extremities. METHODS: We here report on 5 cases of myopericytoma, malignant myopericytoma, and glomangiopericytoma arising from subcutaneous, paraspinal, orbital, and sellar regions that secondarily involved the nervous system. Patients experienced orbital swelling, progressing neuropathic pain, dermatoma specific pain, and oculomotor paresis. RESULTS: Mean age at diagnosis was 56.8 years (range, 38-74 years). After a mean follow-up of 38 months, no recurrence was detected. All tumors were unencapsulated but relatively well-circumscribed lesions, showing typical histologic and immunohistochemical features of soft-tissue myopericytoma, including one malignant case. CONCLUSION: We conclude that myopericytoma may affect the nervous system and for prognostic and therapeutic reasons, needs to be differentiated from other vascular tumors.

A 68-year old man with a cerebellopontine angle tumor.

We report on a 68-year-old male with a cerebellopontine angle tumor manifesting at the 8th cranial nerve and presenting histopathological features of a rhabdomyoma. A literature review revealed four reports of intracranial nerve rhabdomyoma, all of adult type and including one manifestation at the vestibular nerve. We present the first case of a fetal type extracardiac rhabdomyoma manifesting at a cranial nerve. Although rare, rhabdomyomas must be considered in the differential diagnosis of vestibular schwannomas.