Calcifying Pseudoneoplasms of the Skull Base Presenting with Cranial Neuropathies: Case Report and Literature Review

Abstract

Objectives We report our institutional experience with calcifying pseudoneoplasms of the skull base that presented with cranial neuropathies. These lesions are also known as fibro-osseous lesions, cerebral calculi, or brain stones.Results One patient presented with facial numbness and retro-orbital pain secondary to compression of the maxillary branch of the trigeminal nerve at the anterior portion of the infratemporal fossa. The other patient presented with occipital headaches and hypoglossal nerve palsy. This patient was found to have a calcified lesion in the posterior fossa, which eroded the left occipital condyle.Conclusion Calcifying pseudoneoplasms are benign, slow-growing masses that are apparently cured by gross total resection. Even with incomplete tumor resection, the prognosis is considered to be favorable. We advocate a minimally invasive surgical resection of such tumors involving the cranial nerves.

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

“…Clinically, CAPNON can present with pain syndromes, gait disturbance and motor weakness, all symptoms experienced by our patient. Her left‐sided facial droop was thought to be due more to corticospinal tract involvement than cranial neuropathy, which has previously been reported . In the majority of cases of intra‐axial CAPNON, seizures have been the presenting symptom, making our patient no different in this regard.…”

“…Her left-sided facial droop was thought to be due more to corticospinal tract involvement than cranial neuropathy, which has previously been reported. 13 In the majority of cases of intra-axial CAPNON, seizures have been the presenting symptom, 2 making our patient no different in this regard. At 2-month neurology follow-up, the patient was noted to be minimally interactive, had contractures of the left upper extremity and was wheelchair bound, but had no more seizures than her baseline.…”

“…The frequent adjacent granulomatous and inflammatory reaction along with an indolent course and a generally good prognosis support a benign or reactive rather than neoplastic process . Of the 65 cases of CAPNON that we identified in the literature, only one case presented with two separate lesions diagnosed 8 years apart in the same individual . The remaining 64 cases were solitary.…”

“…This entity shows male predominance (1.92:1) but does not seem to have a predilection for an age group . Sixty‐five cases have been reported in the literature, 41 of which were intracranial and mostly intradural, 20 in the spinal canal and four at the craniovertebral junction . Of the 65 reported cases, 64 cases consisted of a solitary lesion, while only one case presented with one initial lesion and the second many years later …”

Brain stones revisited—between a rock and a hard place

“…Calcifying pseudoneoplasms of the neuraxis (CAPNON) are extremely rare fibro-osseous lesions that can be extra- or intra-axial. Histologically, these benign lesions are composed of a pathognomonic chondromyxoid matrix in an amorphous or nodular pattern as well as palisading spindle or epithelioid cells and varying proportions of fibrous stroma [24–26]. When present in the skull base, they are known to symptomatically encase cranial nerves.…”