Calcifying Pseudoneoplasm Of The Neuraxis Research Articles

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.

Posterior Fossa Calcifying Pseudoneoplasm of the Neuraxis (CAPNON): Presentation of Three Surgical Cases.

Calcifying pseudoneoplasm of the neuraxis (CAPNON) is an extremely rare entity with fewer than 150 cases reported in the literature and mostly with a supratentorial or spinal location. Posterior fossa CAPNON has been reported scarcely, and association with perilesional edema is a topic not yet approached which might play a significant role in treatment decision and clinical progression. Our objective is to report, to our knowledge, the first series of 3 posterior fossa CAPNON surgically treated in a single institution and assess features that help provide a systematic approach to diagnosis and timely treatment. This was a monocentric, retrospective study of surgical patients diagnosed with a posterior fossa CAPNON in the last 5years. A thorough bibliographic research was conducted. Three patients were included. Locations involved IV ventricle, right cerebellopontine angle with extension to foramen magnum, and cerebellar vermis. Two of them presented with symptoms linked to acute hydrocephalus, and the other one presented with progressive cranial nerve palsy and brainstem compression signs. The 3 of them showed radiological signs of perilesional edema on their preoperative magnetic resonance imaging. Gross total resection was accomplished in one case, with near and subtotal resections in the others. There were no complications. The outcome was favorable in all cases. It is essential to contemplate this infrequent diagnosis in cases of calcified lesions involving the posterior fossa. When symptoms manifest, surgery should be considered. Perilesional edema could be associated with symptomatic progression and hence a sign suggesting the need for surgical treatment.

Calcifying pseudoneoplasm of the neuraxis within the sellar region: illustrative case.

BACKGROUNDThere are numerous atypical lesions of the sellar and suprasellar region that are often mistaken for pituitary adenomas. It is important to consider rare mimics of more common pathologies in this region.OBSERVATIONSThe authors detail the case of a 37-year-old woman with hypopituitarism who was found to have an atypical sellar mass with slow growth on interval imaging. The lesion was debulked via a microscopic endonasal transsphenoidal approach and found to be a calcifying pseudoneoplasm of the neuraxis (CAPNON).LESSONSCAPNON is a rare disease entity that may affect the sellar region. CAPNON should be on the differential diagnosis for sellar masses that are associated with T1 and T2 hypointensity on magnetic resonance imaging with minimal enhancement. Although CAPNON is not at risk for malignant progression, these benign lesions can continue to grow after a subtotal resection and require follow-up.

Spinal calcifying pseudoneoplasm of the neuraxis (CAPNON) and CAPNON-like lesions: CAPNON overlapping with calcified synovial cysts

Calcifying pseudoneoplasm of the neuraxis (CAPNON) is a rare tumour-like fibro-osseous lesion in the neuraxis including the spine. It is diagnosed by the presence of the following histological features: granular amorphous to chondromyxoid fibrillary cores with calcification/ossification, peripheral palisading of spindle to epithelioid cells, variable fibrous stroma, and foreign body reaction with multinucleated giant cells, as well as positive NF-L immunostaining. Spinal CAPNON is sometimes named as tumoural calcinosis that is tumour-like dystrophic calcification usually in the periarticular tissue and also described in calcified synovial cyst (CSC). We examined clinical, radiological and pathological features of five spinal CAPNONs and 21 spinal CSCs including three recurrent lesions. The results demonstrated some radiological and pathological overlaps between these two entities, as well as distinct features of each entity to be diagnosed. All CAPNONs showed the diagnostic histological features with NF-L positivity mainly in lesion cores and variable CD8+ T-cells. In contrast, CSCs exhibited the synovial lining and variable degenerative/reactive changes with some CAPNON-like features, but mostly no to occasionally limited NF-L positivity and less CD8+ T-cells with statistically significant differences between groups of CAPNONs and CSCs. Four CSCs contained CAPNON-like foci with the CAPNON diagnostic features including prominent NF-L positivity, and some transitional features from CSC to CAPNON. As the pathogenesis of CAPNON is likely reactive/degenerative in association with an inflammatory/immunological process involving NF-L protein deposition, our findings suggest the link between spinal CAPNON and CSC, with possible transition from CSC to CAPNON or CAPNON developing in reaction to CSC.

Diagnostic and pathogenic features of calcifying pseudoneoplasm of the neuraxis

Calcifying pseudoneoplasm of the neuraxis (CAPNON) is a rare tumefactive lesion with unclear pathogenesis. It is diagnosed by pathological findings of the typical histological features that include granular amorphous cores with palisading spindle to epithelioid cells, variable fibrous stroma, foreign-body reaction with giant cells, and calcification/ossification occasionally with psammoma bodies. However, its histopathology may be variable and currently immunohistochemistry plays a limited role in its diagnosis and understanding the pathogenesis. In this study, we examined 6 cases of CAPNONs including 3 intracranial and 3 spinal epidural lesions (age range: 59–69 years; 3 males and 3 females). Immunohistochemistry revealed that all CAPNON cores contain abundant positive deposits of neurofilament protein (NFP), which was supported by electron microscopy finding of filaments (8–13 nm in diameter). In comparison, no NFP positivity was found in 5 psammomatous/metaplastic meningiomas or 7 intervertebral tissue lesions with calcification/ossification. In addition, CAPNON cellular areas showed variable numbers of CD8+ cytotoxic T-cells with less CD4+ T-cells and a decreased ratio of CD4/CD8+ cells, versus the intervertebral tissue lesions without CD8+ or CD4+ cells. Our findings suggest that NFP may be a principal constituent of CAPNONs, and thus involved in the pathogenesis of CAPNON. Given the decreased CD4/CD8 ratio, the pathogenic process of CAPNON is possibly immune- mediated.LEARNING OBJECTIVESThe presentation will enable the learner to: 1.Discuss histopathological features of calcifying pseudoneoplasm of the neuraxis (CAPNON) with variation of non-core components.2.Explore diagnostic and pathogenic roles of immunohistochemical markers including neurofilament protein and CD4/CD8 in CAPNON.

Immunohistochemical Markers in the Diagnosis of Calcifying Pseudoneoplasm of the Neuraxis.

Calcifying pseudoneoplasm of the neuraxis (CAPNON) is a rare tumor-like lesion with unknown pathogenesis. It is likely under-reported due to diagnostic challenges including the nonspecific radiographic features, lack of diagnostic markers, and often asymptomatic nature of the lesions. We performed detailed examination of 11 CAPNON specimens diagnosed by histopathology, with the help of electron microscopy and immunohistochemistry. Electron microscopy revealed the presence of fibrillary materials consistent with neurofilaments. In addition to some entrapped axons at the periphery of CAPNONs, we discovered that all specimens stained positive for neurofilament-light (NF-L) within the granular amorphous cores, but not neurofilament-phosphorylated (NF-p). CAPNONs also showed variable infiltration of CD8+ T-cells and a decreased ratio of CD4/CD8+ T-cells, suggesting an immune-mediated process in the pathogenesis of CAPNON. NF-L and CD4/CD8 immunostains may serve as diagnostic markers for CAPNON and shed light on its pathogenesis.

Letter to the Editor Regarding “Case of Calcifying Pseudoneoplasms of the Neuraxis Coexisting with Interhemispheric Lipoma and Agenesis of the Corpus Callosum: Involvement of Infiltrating Macrophages”

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.

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. 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. 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 Neuraxis (CAPNON) – A case report

We report a case of a 32-year-old male with chronic headaches due to two calcified cerebellar lesions. The patient underwent surgical resection. Under microscopy, the tumour consisted of a calcified mass with prominent fibrillary architecture and associated chondroid matrix. The mass had a distinct interface with adjacent cortex, with areas showing a palisaded rim of epithelioid macrophages mixed with occasional meningeal cells. Immunohistochemistry showed that the palisaded rim of macrophages were CD68 positive and the occasional meningeal cells positive for EMA and PR. The morphology and immunoprofile is consistent with a calcifying pseudoneoplasm of the neuraxis (CAPNON).

Pseudo-tumeur calcifiante du névraxe

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare lesions of the central nervous system. To date, about 60 cases have been reported in literature. We present a case that had the peculiarity to occur in a pregnant woman. At 32 weeks of gestation, a 26-year-old woman was hospitalized to explore nocturnal epigastralgia. During the hospitalisation, the patient presented generalised seizures. As an eclampsia had been suspected, a caesarean delivery was performed. Post-operatively, the patient harboured memory disorders and neuro-imaging explorations were done. They showed an intracerebral calcified mass located in the left frontal lobe and surrounded by an oedema. A complete surgical resection was performed. Histological examination of the surgical specimen showed a calcified tissue containing a fibrillary or granular material. A dense and hyalinised eosinophilic material focally surrounded the calcifications and contained regular fusiform cells of fibroblastic type. Foci of lipomatous and osseous metaplasia were present. Immunohistochemical staining for EMA and STAT6 was negative. There was no associated meningioangiomatosis nor tumour proliferation. Forty-five months after surgery, the patient did not present any seizures and had no sequelae. CAPNON are rare lesions occurring at any age. Their location in the central nervous system is ubiquitous and they can be intra or extra axial. The treatment is surgical and the prognosis excellent. CAPNON must be recognized and distinguished from the other calcified lesions, tumoural or non-tumoural, to avoid an inadequate and potentially harmful treatment.

Calcified otogenic brain abscess.

We read with interest the recent NeuroImage presented by Ye et al.1 as an example of calcified otogenic brain abscess. The authors described a patient with a 2-year history of recurrent episodes of purulent discharge from the left ear and an incidental calcified brain mass in the ipsilateral temporal lobe.1 In the largest case series of calcifying pseudoneoplasm of the neuraxis (CAPNON), all …

Calcifying Pseudoneoplasms of the Neuraxis (CAPNON): Case Series and Literature Review (P4.259)

Calcifying Pseudoneoplasms of the Neuraxis (CAPNON): Case Series and Literature Review (P4.259)

Calcifying pseudoneoplasm of the neuraxis overlying the corpus callosum: a case report and review of the literature

Calcifying pseudoneoplasms of the neuraxis (CPN), also known as fibroosseous lesions, are slow-growing lesions that can occur in a variety of regions of the central nervous system (CNS). These lesions are especially rare, with no more than 30 intracranial cases reported in the literature. Due to its non-malignant/non-metastatic course, one can expect an excellent prognosis with a successful complete resection. However, depending on the location of presentation within the CNS, CPN can present unique challenges in diagnosis and subsequently, the treatment course undertaken. We present a case of an intracranial, extra-axial CPN in a 49-year-old woman, the second to be reported in this location ever and first in 30 years, and detail the clinical, histopathologic and radiological features of a CPN along with a review of the literature.

An unusual association of calcifying pseudoneoplasm of the neuraxis with interhemispheric lipoma and agenesis of corpus callosum

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare tumours that can occur anywhere in the central nervous system. The aetiology and natural history of these lesions is unclear. We report an unusual case of intraparenchymal CAPNON that occurred in association with interhemispheric lipoma and agenesis of the corpus callosum. The patient was a 47-year-old woman with known congenital absence of corpus callosum who presented with a progressive 6-month history of worsening headache, ataxic gait, blurred vision and poor memory. Magnetic resonance imaging (MRI) revealed complete agenesis of the corpus callosum with associated interhemispheric lipoma and an unusual calcified intra-parenchymal mass, largely hypointense on T2 with intermediate signal centrally on T1, surrounded by an ill-defined vasogenic oedema. Histologically, the first lesion was confirmed as lipoma. The second lesion consisted of multiple nodules of chondromyxoid matrix partially rimmed by a single layer of palisading spindled to epithelioid cells and focal osseous metaplasia including mature lamellar bone. The final diagnosis was CAPNON associated with interhemispheric lipoma and agenesis of the corpus callosum. To our knowledge, this is the first reported association between these uncommon lesions. CAPNON have relatively non-specific radiological features with a broad differential diagnosis, but have distinctive histological features. Accurate identification of CAP-NON will help avoid misdiagnoses and unnecessary therapeutic procedures since wide local excision is curative.

Calcifying pseudoneoplasms of the neuraxis (CAPNON): clinical features and therapeutic options

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare, slow-growing lesions occurring anywhere in the central nervous system (CNS). Since their first description in 1978, only 39 cases have been reported in the literature. The cases of two patients with histopathologically verified diagnoses of CAPNON are presented. Thereafter, we review all reports published so far with respect to study type, number of patients, anatomical area (intracranial, spinal, or both), clinical presentation, radiological presentation, therapy, duration of follow-up, incidence and type of complication, and outcome. Furthermore, current recommendations for the management of spinal and cerebral CAPNON are discussed. A total of 19 retrospective articles were identified and selected for review: 6 case series (31.6%) and 13 reports of single cases (68.4%). The 19 articles and our two additional cases added up to a total of 19 patients with spinal CAPNON and 22 patients with intracranial CAPNON. All patients were treated surgically. A follow-up was provided in 13 patients with spinal (68.4%) and in 16 patients with intracranial CAPNON (72.7%), respectively. The follow-up showed no signs of recurrence in 12 of 13 patients with spinal CAPNON (92.3%) and in 15 of 16 patients with intracranial CAPNON (93.7%). One-tailed Fisher's exact test revealed no significant difference between complete and incomplete resection in terms of disease recurrence (spinal: p = 0.6842; intracranial: p = 0.3749). Analysis of the literature did not reveal any deaths directly associated with CAPNON. Calcifying pseudoneoplasms are rare benign lesions of the CNS of yet unknown origin. Because of the increasing number of reports, this clinical entity should be taken into consideration in the differential diagnosis of intracranial and intraspinal calcified lesions.

Imaging features of calcifying pseudoneoplasms of the neuraxis

Objective To identify the imaging characteristics of calcifying pseudoneoplasms of the neuraxis (CAPNON) and do literature review.Methods Five patients of pathologically-proved CAPNON underwent preoperative MR examination,among which 4 underwent CT scan,2 underwent DSA examination and 1 underwent SPECT. All imaging data were retrospectively analyzed with the emphasis on imaging characteristics.Results Five patients of CAPNON with the diameter of 1.5 to 5.0 cm were found in five patients ( Male 4 ; Female 1 ; age 25 to 60 years old ).Three lesions were located in the skull base,one was located in the cervical spine and one in the foramen magnum and upper cervical segment. All patients underwent MRI examination and 4 of them also took CT scanning.On plain CT,all lesions showed obvious calcification.On T1WI all masses showed hypointensity,and on T2WI 4 of the lesions showed iso- or hypointensity and 1 heterogeneous signal intensity. On contrast-enhanced MR images, peripheral enhancement was demonstrated in 3 lesions,homogeneous enhancement was found in case and one lesion showed no enhancement. The pathologic analysis indicated that inside the lesions were abundant calcification,fibroepithelial tissue and mucoid matrix and no edema was detected around the lesions.Conclusions CAPNON displayed the predilection to male adults and the neuraxis was the predilection site.Calcification on CT images,hypointensity on MR images and peripheral enhancement will be helpful for the diagnosis of CAPNON,but the final confirmation still needs the pathologic results. Key words: Granuloma;  Magnetic resonauce imaging;  Tomography, X-ray computed

Endoscopic resection of calcifying pseudoneoplasm of the neuraxis (CAPNON) of the anterior skull base with sinonasal extension

We present a calcifying pseudoneoplasm of the neuraxis (CAPNON) of the anterior skull base that was resected endoscopically. The clinical details are reported with a review of the relevant literature. CAPNON, although rare, should be considered in the differential diagnosis of tumors presenting along the anterior skull base with radiographic characteristics consistent with a fibro-osseous lesion. Endoscopic resection of these lesions is feasible in select patients with sinonasal extension.

Calcifying Pseudoneoplasm of the Neuraxis (CAPNON) of the Anterior Skull Base: Report of a Case

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare, benign, fibro-osseous lesions of the central nervous system. They can occur anywhere in the central nervous system, and arise with roughly equal frequency in the spine and brain parenchyma. The etiology of these lesions is uncertain, but they are thought to arise from a reactive as opposed to a neoplastic process. Treatment of these lesions is typically with surgical excision. Herein, we report a case arising in a 19-year-old man presenting with chronic headache, unilateral rhinorrhea, and epiphora. The lesion was located along the anterior skull base, with sinonasal and orbital extension. The lesion was resected using an endoscopic, transethmoidal approach.

An unusual association of calcifying pseudoneoplasm of the neuraxis with interhemispheric lipoma and agenesis of corpus callosum: case report

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare tumours that can occur anywhere in the central nervous system. The aetiology and natural history of these lesions is unclear. We report an unusual case of intraparenchymal CAPNON that occurred in association with interhemispheric lipoma and agenesis of the corpus callosum. The patient was a 47-year-old woman with known congenital absence of corpus callosum who presented with a progressive 6-month history of worsening headache, ataxic gait, blurred vision and poor memory. Magnetic resonance imaging (MRI) revealed complete agenesis of the corpus callosum with associated interhemispheric lipoma and an unusual calcified intra-parenchymal mass, largely hypointense on T2 with intermediate signal centrally on T1, surrounded by an ill-defined vasogenic oedema. Histologically, the first lesion was confirmed as lipoma. The second lesion consisted of multiple nodules of chondromyxoid matrix partially rimmed by a single layer of palisading spindled to epithelioid cells and focal osseous metaplasia including mature lamellar bone. The final diagnosis was CAPNON associated with interhemispheric lipoma and agenesis of the corpus callosum. To our knowledge, this is the first reported association between these uncommon lesions. CAPNON have relatively non-specific radiological features with a broad differential diagnosis, but have distinctive histological features. Accurate identification of CAP-NON will help avoid misdiagnoses and unnecessary therapeutic procedures since wide local excision is curative.