Calcifying pseudoneoplasm of the spine: imaging and pathological features

Spinal calcifying pseudoneoplasms of the neuraxis: A case report and review of the literature

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare, non-neoplastic, slow-growing tumors that can present anywhere throughout the central nervous system. While the etiology of these lesions remains unknown, the mainstay of treatment is surgical excision. We describe a case of CAPNON at our institution in a 66 year-old female patient who presented with 5 months of pain and burning sensation in her thigh. On MRI, an intradural extramedullary lesion was identified at the level of T11-T12. The mass was surgically excised and the patient reported resolution of her symptoms by her six week follow-up appointment. We reviewed 79 spinal CAPNON cases, covering all cases reported in the literature thus far. In summary, we find that spinal CAPNON are most commonly lumbar and extradural in location, with pain as the most common presenting symptom. Lesions are well-defined and hypointense on T1 and T2 MRI sequence. The majority of cases had favorable surgical outcomes with near complete resolution of pain and associated symptoms.

Spinal calcifying pseudoneoplasm of the neuraxis (CAPNON) associated with facet joint pathologies: CAPNON diagnostic and pathogenic insights

Calcifying pseudoneoplasm of the neuraxis (CAPNON) is a rare tumor-like fibro-osseous lesion that can develop anywhere in the neuraxis. Approximately a half of reported CAPNONs developed in the spinal region, mostly close to the facet joint (FJ). The diagnosis of spinal CAPNONs is challenging given the existence of mimics and associated pathologies including calcific degeneration of the FJ ligaments (DFJL) and synovial cysts (SCs). The pathogenesis of CAPNON remains elusive, although there have been a few hypotheses including degenerative, reactive, proliferative and immune-mediated processes. Our present study examined clinical, radiological and pathological features of 12 spinal CAPNONs in comparison to 9 DFJL foci, and diagnostic and pathogenic relationship between CAPNONs and FJ pathologies. On imaging, CAPNONs were all tumor-like and typically bigger than DFJL foci. All CAPNONs showed pathologically diagnostic features including characteristic cores, consistently identifiable core-surrounding/peripheral palisading of macrophages and other cells including multinucleated giant cells, variable infiltration of CD8+ T-cells, and multifocal immunopositivity of neurofilament light chain (NF-L). These features were absent or limited in the DFJL foci with statistically significant differences from CAPNONs, except calcifications. Spinal CAPNONs co-existed with DFJL foci in all cases; some had transitional foci with overlapping focal CAPNON and DFJL-like features. These findings, along with our previously reported relationship between CAPNONs and SCs, suggest that spinal CAPNONs may occur in association with or in transition from calcifying/calcified degenerative lesions of FJ ligaments and/or SCs when a reactive proliferative process is complemented by other pathogenic changes such as immune-mediated pathology and NF-L deposition/expression.

A case report of bilateral lateral ventricle calcified pseudoneoplasm of the neuraxins

BACKGROUND

Calcifying pseudoneoplasm of the neuraxis (CAPNON) is indeed a rare central nervous system lesion that can occur in central nervous system (CNS). Due to its infrequency and limited literature reports, it is challenging to diagnose and manage CAPNON.

CASE PRESENTATION

In this intriguing study, we embarked on a quest to uncover the story of a 16-year-old girl who experienced bothersome headaches. Through advanced imaging techniques like computed tomography (CT) and magnetic resonance imaging (MRI), we glimpsed a delicate calcified growth within the lateral ventricles' posterior horn. Motivated by our unwavering commitment to solving mysteries, we embarked on a surgical journey that not only freed the young patient from her ailment but also shed light on the true nature of her puzzling adversary-a remarkable CAPNON.

CONCLUSIONS

For patients with CAPNON who have multiple or non-respectable lesions, the primary goal is to alleviate symptoms. After alleviating the symptoms with partial resection, close monitoring of any residual lesions is essential. If there is no evidence for disease progression, a strategy of continued close observation is appropriate.

A Quick and Comprehensive Guide to Differential Diagnosis of Neck and Back Pain: a Narrative Review

The list of diagnostic options when approaching a patient with axial pain is impressively complex. Many offer limited diagnostic workups, but we could not find a truly comprehensive diagnostic guide to assist in the diagnostic evaluation. In this short paper, we briefly described a long list of medical conditions, each of which can manifest as back or neck pain, and whose prevalence ranges from common to very rare. We then proposed an algorithm for classifying them into subgroups. Further referral to diagnostic tests and specialist consultations, after assignment to one of those subgroups, could save time and unnecessary tests. We believe that this review and the proposed diagnostic algorithm can be valuable for medical education and for use in the primary care setting for the diagnostic evaluation of any type of back or neck pain in all patient groups.

Percutaneous spine biopsy under cone beam computed tomography guidance for spondylodiscitis: Time is diagnosis

BACKGROUND AND PURPOSE

Percutaneous spine biopsies for spondylodiscitis have been long discussed due to the low microbiologic yield. This retrospective study evaluated factors of cone beam computed tomography-guided spine biopsies that may affect microbiologic yield.

METHODS

We retrospectively reviewed percutaneous spine biopsies under cone beam computed tomography for spondylodiscitis performed from January 2015-December 2020. Clinical and technical features such as the time from initial symptoms to biopsy, level biopsied, biopsy needle type/gauge, technical approach, radiation dose, technical success and microbiologic yield were recorded. Pre-procedure magnetic resonance imaging findings were also recorded such as the number of vertebral bodies involved, and disc morphology. Univariate logistic regression analysis and Receiver operating characteristic analysis were performed to assess any relationship between relevant factors and positive cultures.

RESULTS

A total of 50 patients underwent cone beam computed tomography-guided biopsies for spondylodiscitis, with resulted positive cultures in 18 patients (36%). The mean time from the initial referral of spinal symptoms to procedure in the positive culture group was the most influential finding for positive cultures (odds ratio 56.3, p < 0.001). Among magnetic resonance imaging findings, thin or degenerated intervertebral disc was a negative factor for positive cultures (odds ratio 0.09, p = 0.006). Univariate analysis showed that percutaneous approach (transpedicular vs posterolateral/interlaminar) needle size (11-13 g vs 16-18G, odds ratio 1.2, p = 0.7) and site of biopsy (disc vs bone vs disc plus endplate) did not significantly affect the microbiologic yield of spine biopsy.

CONCLUSION

Percutaneous cone beam computed tomography-guided biopsy for spondylodiscitis is a reliable and safe technique and its microbiologic yield may increase if biopsy is performed within the acute phase of infection.

Calcifying Pseudoneoplasm of the Neuraxis: From Pathogenesis to Diagnostic and Therapeutic Considerations

Calcifying pseudoneoplasm of the neuraxis (CAPNON) is a rare tumefactive lesion that can develop anywhere within the neuraxis. The incidence is likely underreported, given its nonspecific imaging features and because CAPNON has often been overwhelmed by the presence of comorbid disease. CAPNON is typically diagnosed by the histopathological examination findings. However, the histopathological diagnosis is often challenging owing to the existence of similar calcifying pathological entities. Although the pathogenesis of CAPNON has remained elusive, emerging evidence supports a reactive proliferative and immune-mediated process involving the aggregation of neurofilament light chain protein and the infiltration of immune cells. The management of CAPNON is largely dependent on the symptoms, which are mainly related to the location and associated mass effects. Maximal surgical resection will result in excellent patient outcomes with rare recurrence, especially in patients presenting with epilepsy. The discovery of neurofilament light chain protein within CAPNON suggests that neurofilament might be implicated in the pathogenesis of CAPNON, serve as an immunohistochemical marker to improve the diagnostic accuracy of CAPNON, and hold therapeutic potential for the treatment of CAPNON.

New insights into calcifying pseudoneoplasm of the neuraxis (CAPNON): a 20-year radiological-pathological study of 37 cases

AIMS

Calcifying pseudoneoplasm of the neuraxis (CAPNON) is a rare entity that can occur anywhere within the central nervous system. Histologically, CAPNON has been characterised as a benign, calcified, fibro-osseous lesion with a characteristic chondromyxoid fibrillary matrix with dense calcification and varying degrees of spindle, epithelioid, fibrous, meningothelial and giant cells. The underlying aetiology of CAPNON is controversial and incompletely understood. The aim of this study was to perform a comprehensive radiological and histological review to further characterise this entity.

METHODS AND RESULTS

In this article, we review our institutional 20-year experience including 37 cases of CAPNON with detailed pathological analysis, evaluation of concurrent lesions, correlation with radiological imaging, and critical review of the literature. The classic histological finding of chondromyxoid matrix was present in one-third of cases. Underlying or dual pathologies were frequent, and included diverse underlying conditions. Radiologically, dense calcification and dural attachment were the most common features. Enhancement was often low, but was more prominent in the setting of inflammatory changes, aggressive growth, and dual pathology.

CONCLUSION

Our results suggest that CAPNON represents a spectrum of reactive processes that can arise in association with diverse underlying pathologies, including inflammatory, degenerative, vascular and neoplastic lesions.

Calcifying pseudoneoplasm of the neuroaxis presenting with refractory seizures: Case report and literature review

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare benign lesions that can arise anywhere within the central nervous system. The etiology of these lesions remains unknown and diagnosis is made on pathohistological analysis. We present the case of a 35-year-old male patient with a history of epilepsy since childhood who was evaluated for refractory seizures. MRI revealed a small lesion in the left-posterior temporal lobe suspected to be a cavernoma. A gross total resection of the lesion was achieved via a left temporal craniotomy and pathological analysis revealed CAPNON. At 6 months follow-up, the patient remained neurologically intact and his seizures had ceased.

Calcifying Pseudoneoplasm of Neuraxis (CAPNON) in the Posterior Third Ventricle-Challenge for Neuroendoscopy

BACKGROUND

We report the first case of a purely intraventricular calcifying pseudoneoplasm of neuraxis (CAPNON) in the posterior third ventricle.

CASE DESCRIPTION

A 63-year-old male without any previous medical history presented with Hakim triad. Imaging showed a calcified lesion of the posterior third ventricle with hydrocephalus. An endoscopic third ventriculostomy was performed. Endoscopic removal or debulking of the lesion was impossible due to its rock-hard consistency, and thus the procedure was aborted after biopsy.

CONCLUSIONS

When encountering such calcified lesions within the ventricular system, especially in proximity to eloquent regions, the decision making process should include the hard consistency and parenchymal adhesions as obstacles to neuroendoscopic removal. Even for biopsy, a higher morbidity rate compared with typical soft tumors should be assumed. Although data on intraventricular CAPNON is limited, biopsy of the lesion and treatment of associated hydrocephalus appear to be the primary neurosurgical goals, followed by imaging surveillance.

Surgically treated intracranial supratentorial calcifying pseudoneoplasms of the neuraxis (CAPNON) with drug-resistant left temporal lobe epilepsy: A case report and review of the literature

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare pathological lesions that can present anywhere in the central nervous system. Symptoms vary depending on the location, though they often include seizures, especially in intracranial and supratentorial lesions. A case of intracranial supratentorial CAPNON presenting with drug-resistant left temporal lobe epilepsy is reported. The patient had a history of drug-resistant focal seizures for over 36 years. The lesion was located in the left mesial temporal lobe, but hippocampal sclerosis and hippocampal invasion were not apparent. The lesion was removed without hippocampectomy, and the patient has been seizure-free for one year.