Calcifying pseudoneoplasms of the neuraxis (CAPNON). A case report.

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare, slow-growing, benign lesions occurring throughout the neuroaxis that are frequently misdiagnosed and overlooked by clinicians. Here, we report a case of a 56-year-old woman who presented with a history of recurrent headache for the previous six years. Magnetic resonance imaging (MRI) revealed a 2.3-cm-sized solid mass in the right frontal lobe that was surrounded by marked edematous areas. The lesion demonstrated dense calcification and avid enhancement. The lesion was initially diagnosed as oligodendroglioma, and then found to be CAPNON based on histopathology of a surgically resected tissue. Genetic analysis revealed a nonsense mutation in the CUL4B gene. The patient's condition appeared to reflect a reactive, rather than neoplastic, process. Clinicians should be prepared to detect such pseudotumors histopathologically in order to avoid unnecessary differential tests of neoplastic or infectious diseases, as well as potentially harmful therapies.

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.

Multiple calcifying pseudoneoplasms of the neuraxis (MCAPNON): Distinct entity, CAPNON variant, or old neurocysticercosis?

We report a case of multiple calcifying pseudoneoplasms of the neuraxis (MCAPNON) with associated multifocal perivascular microcalcifications and vascular calcinosis. Calcifying pseudoneoplasm of the neuraxis (CAPNON) is a very rare condition that may arise in extra-axial and occasionally, in intra-axial locations. Moreover, it is nearly always a solitary mass with only one case with two lesions reported. While the etiology and pathogenesis of CAPNON remains unclear, the histopathology findings of this entity have been well described. We report a case of a 62-year-old woman with 18 calcifying radiologic lesions involving bilateral cerebral hemispheres. Histologically, these lesions have features similar to that reported for CAPNON, including nodular calcification with fibro-osseous components and peripheral histiocytic reaction. The patient had a poorly documented diagnosis of neurocyticercosis 32 years prior, although without tissue confirmation. The lack of detectable cysticercus serum antibody titers, and absence of residual larval or cyst wall tissue render multifocal calcific involution of that parasite unprovable although still plausible. We also raise the possibility of a blood-brain barrier derangement and/or a metabolic disorder as an alternative etiology. Whether this case of MCAPNON shares the same pathogenesis as the usual solitary CAPNON is unclear.

Multiple calcifying pseudoneoplasms of the neuraxis.

Calcified pseudoneoplasms of the neuraxis (CAPNON) are a rare diagnostic entity. They have been reported intra-cranially as well as in the spine, and are most commonly found at the skull base. This is a case report of a 38-year-old woman who presented with bilateral CAPNON, diagnosed 8 years apart. While there are approximately 46 reported in the current literature of cerebral and spinal fibro-osseous lesions, this is the first report of separate lesions.

Calcifying pseudoneoplasm of the foramen magnum--Case report and review of the literature.

We present a case of a 29-year-old male with a calcifying pseudoneoplasm of the neuraxis (CAPNON) located in the region of the foramen magnum, treated successfully by complete resection. After a 2-year follow-up the patient remains recurrence free. Clinical and histopathological characterization of CAPNON is provided with special emphasis on the intraoperative and neuroradiological features of the lesion.

Calcified Pilocytic Astrocytomas and Calcifying Pseudoneoplasms of the Neuraxis: A Diagnostic Challenge.

Pilocytic astrocytoma (PA), recognized as the most prevalent central nervous system (CNS) tumor, has long been associated with calcifications, a characteristic often attributed to benign or indolent growth patterns. In this study, we explored the calcified attributes in these tumors that beckon a deeper understanding. This is a retrospective study, on a set of seven cases, with a histopathological diagnosis of pilocytic astrocytoma with calcifications and psammoma bodies (PB). Despite an encouraging overall survival outcome, the recurrence in four cases cast some doubt on the conventional classification. The histological study of these cases revealed a spectrum of calcifications, varying in size and morphology, all of which exhibited positive reactivity to glial fibrillary acidic protein (GFAP), osteoconduction, and osteopontin. Notably, the immunohistochemistry showed hyaline bodies displaying an atypical immune profile, strikingly negative for vimentin and GFAP, and a robust positivity for epidermal growth factor receptors (EGFR), tumor necrosis factor-alpha (TNF-α), and interleukin 1 beta (IL-1ß). These results stimulated speculation that the identity of these calcified tumors may have extended and potentially embraced the realm of calcifying pseudoneoplasms of the neuraxis (CAPNON), underscored by intense pilot gliosis. This study transcends mere anatomical exploration; it delves into the intricacies of calcified tumors, casting a spotlight on the dynamic interplay between PA and CAPNON. As we traverse the frontiers of neuro-oncology, these findings pave the way for innovative avenues in the diagnostics and therapeutics of these tumors.

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.

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.

Calcifying Pseudoneoplasm of the Neuraxis: An Institutional Series of Ten Cases and Review of the Literature to Date.

BACKGROUND: Calcified pseudoneoplasms of the neuraxis (CAPNONs) are rare, fibro-osseous lesions with an unknown cause that may present anywhere along the neuroaxis. Little is known about how intracranial CAPNONs present and about patients' long-term outcomes. METHODS: A retrospective institutional review of intracranial pathology-confirmed CAPNONs was performed. Presenting clinical features, management, and clinical outcomes are highlighted. A literature review of intracranial CAPNON lesions was also performed to build on our series. RESULTS: Ten patients were identified who met the inclusion criteria. Most patients presented with headaches (n = 6; 60%), seizures (n = 5; 50.0%), and neck and facial pain (n = 3; 30.0%). Most lesions were supratentorial (n = 7; 70.0%), with 3 infratentorial origins. Surgical resection was the most common initial management undertaken (n = 7; 70.0%). No new permanent postoperative neurologic deficits were identified. The median clinical and/or radiographic follow-up for all patients was 6.8 years (range, 0.7-23.3 years), with no recurrence of disease for 5 patients who underwent gross total resection. Four of 5 patients with residual or nonresectable lesions showed no interval growth on radiographic follow-up; 1 patient showed progression and worsening of presenting symptoms 2 months after resection. Resection substantially improved seizures and headaches in patients presenting with these symptoms (80% and 83.3%, respectively). CONCLUSIONS: Intracranial CAPNONs may present with a wide variety of symptoms characteristic of the site of origin. The outcomes of these symptoms regarding survival and disease control are generally favorable, although resection does not always yield complete resolution of presenting deficits in certain patients, particularly those presenting with headaches or neck/facial pain.

Benign Intracranial Calcified Lesion or a So-Called Brain Stone: A Challenging Diagnosis.

Brain stone is an umbrella term for benign intracerebral calcifications and may be associated with various diagnoses. The surgical decision should be made on a case-by-case basis. Sometimes, conservative management should be considered, irrespective of the underlying pathology. We present a critical case with a brain stone treated conservatively. A 17-year-old female patient was admitted to our department with a headache. The neurological examination revealed no abnormal findings. Cranial CT and MRI scans showed a contrast-enhanced, highly calcified lesion located deep in the white matter at the level of the left centrum semiovale. Surgery was found unnecessary. The patient presented no neurologic deficits or symptoms during the three-year follow-up period. In this case, the differential diagnosis included arteriovenous malformations (AVMs), cavernomas, calcifying pseudoneoplasms of the neuroaxis (CAPNON), etc. The localization of the lesion, expression of the symptoms, and potential outcomes of a possible surgery should be carefully estimated before making the final decision. In summary, conservative treatment should also be considered for critically located, benign calcified lesions, irrespective of pathology, unless they cause intense neurologic symptoms or deficits.

Calcifying pseudoneoplasm of the neuraxis (CAPNON): Unraveling a rare non-neoplastic calcified central nervous system lesion.

INTRODUCTION AND IMPORTANCE: Calcifying pseudoneoplasms of the neuraxis (CAPNON) are infrequent benign brain tumors. They demonstrate slow growth and are characterized by calcium deposits within the tumor tissue. CAPNONs are observed in the supratentorial compartment of the brain. Due to their rarity, increasing knowledge of CAPNONs is essential for accurate diagnosis and effective management of affected patients. This report describes a case of CAPNON diagnosed in a 56-year-old female and discusses the clinical, imaging, and histopathological findings of this rare entity. CASE PRESENTATION: A 56-year-old female presented with a history of recurrent holocranial headache and dizziness, progressively worsening over the last month. Physical and neurological examinations revealed no evident abnormalities. Brain magnetic resonance imaging revealed a calcified and cystic mass, measuring 40 × 32 mm in the right frontal lobe. Complete excision of the mass was done. Histologically, the lesion was composed of glial tissue with abundant amorphous lamellar calcification and a myxoid matrix in the background. Concentric circular calcifications were observed with osseous metaplasia present in some areas. Palisading spindle to epithelioid cells was noted around the lesion. The final diagnosis was CAPNON. The postoperative course was uneventful, and one year of follow-up revealed no signs of recurrence. DISCUSSION: CAPNON typically occurs in middle-aged adults and can present with variable symptoms depending on its location within the brain, including seizures, headaches, or neurological deficits. Surgical resection is considered the optimal treatment for CAPNON. Raising awareness and understanding of this rare entity is necessary for accurate diagnosis and management of patients affected by this condition.

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

BACKGROUND: There 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. OBSERVATIONS: The 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). LESSONS: CAPNON 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.

Surgical Treatment of IV Ventricle Calcifying Pseudoneoplasm of the Neuraxis (CAPNON) Operative Nuances.

Calcifying pseudoneoplasm of the neuroaxis (CAPNON) is a rare, slow growing, and generally benign fibro osseous mass that can emerge throughout the entire central nervous system (CNS). When diagnosed, prompt surgical treatment can determine a good neurological outcome and possibly curative resolution. The objective of the present work is to present a step by step technical report with its video. We present a 37 year old female presented with occipital headache and cervical pain associated with dysphagia, nausea, and gait disturbances. Computed tomography (CT) scan showed a focal calcified lesion on the floor of the IV ventricle projecting toward the vermis with associated supratentorial hydrocephalus and transependymal edema. The telovelar approach was chosen for the procedure. The outcome was favorable, with no complications. Postoperative CT was performed, which revealed no residual lesion. A step by step report of a IV ventricle CAPNON that manifested with hydrocephalus is described.

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

BACKGROUND: 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. METHODS: This was a monocentric, retrospective study of surgical patients diagnosed with a posterior fossa CAPNON in the last 5 years. A thorough bibliographic research was conducted. RESULTS: 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. CONCLUSIONS: 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 Presenting with Vasogenic Edema and a Perilesional Cyst.

Calcifying pseudoneoplasms of the neuraxis (CAPNONs) are uncommon benign lesions that are rarely diagnosed radiographically. We report an unusual case of a left middle cerebellar peduncle CAPNON with vasogenic edema and a perilesional cyst. The patient was a 36-year-old woman with a 20-year history of left-sided hearing loss that had recently progressed. Computed tomography and magnetic resonance imaging showed a heterogenous calcified lesion with vasogenic edema and a perilesional cyst in the left middle cerebellar peduncle. Although it is a rare radiographic feature of CAPNON, vasogenic edema should be included as a possible feature of this uncommon tumefactive lesion.

Calcifying Pseudoneoplasm of the Neuraxis in the Posterior Fossa: A Case Report and Literature Review.

Calcifying pseudoneoplasm of the neuraxis are rare fibro-osseous lesions that can occur throughout the central nervous system. This paper reports one case of this lesion within the posterior fossa and contains a literature review of all cases documented within the posterior fossa to date. A 53-year-old female patient with a history of epiphora, facial irritation, and headaches was found to have a mass centered in the posterior fossa. The patient underwent surgical resection for removal of the mass. Upon review by pathology, the final diagnosis was consistent with calcifying pseudoneoplasm of the neuraxis.

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 the neuraxis: A case report and review of the literature.

Calcifying pseudoneoplasms of the neuroaxis (CAPNON) are rare, slow-growing, fibro-osseous lesions that can occur throughout the entire neuroaxis with few reported cases. We describe a case of craniocervical CAPNON that was treated by our unit and review the available literature. CAPNON are rare benign lesions occurring throughout the neuroaxis. Although rare, these lesions should be considered in cases of histopathological and radiology features of calcified lesions in both brain and spine. Despite a paucity of reports complete safe surgical resection should remain the goal to obtain the best clinical outcomes.

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.

Calcifying Pseudoneoplasm of the Neuraxis, Cerebellum and Cognition: A Rare Opportunity to Learn More.

Calcifying pseudoneoplasms of the neuraxis (CAPNON) are rare tumours. We describe a CAPNON in the posterior fossa and its associated neuropsychological sequelae to provide further evidence for the role of cerebellum in cognitive function. We report the clinical details, imaging, pre-operative neuropsychological assessment, histological features and management of a patient with such a tumour in the posterior fossa location. Detailed pre-operative neuropsychological assessment identified a number of cognitive deficits that had the hallmarks of dysexecutive syndrome. Post-surgery, there was considerable improvement, most notably on processing speed tasks and selected executive tests. This rare case provides further evidence for the role of cerebellum in cognitive function.