Teaching NeuroImage: Primary cerebral amyloidoma mimicking CNS neoplasm

Long-Term Progression of a Residual Cerebral Amyloidoma: An Illustrative Case and Systematic Review

OBJECTIVE

Cerebral amyloidomas (CA) are exceptionally rare tumor-like lesions composed of cerebral amyloid-beta, which is derived from the cleavage of the amyloid precursor protein.

METHODS

We presented a case of recurrent CA and performed a systematic review, comparing their initial presentation, imaging features, neurosurgical treatment, and natural history of the disease.

ILLUSTRATIVE CASE

A 65-year-old male with a history of right homonymous hemianopsia, who underwent subtotal resection of a CA 19 years before, presents to the emergency department with right hemiparesis, dysarthria, and a new onset of clonic seizures. Imaging revealed a left parieto-occipital lesion with calcifications and vasogenic edema. A gross-total resection was performed. Histopathology revealed a hypocellular eosinophilic lesion consistent with CA. Postoperatively, the patient recovered without new neurological deficits. One-year follow-up magnetic resonance imaging showed no residual or recurrence lesion.

SEARCH RESULTS

Eighty-seven cases, including ours, revealed that 65.5% (n = 57) were females with a median age of 54 years (IQR: 46-62). Most lesions were solitary (82.7%; 72 of 87 lesions). Frontal and parietal lobes were most commonly affected with 32.9% (n = 28) and 30.5% (n = 26), respectively. Seizures were the most common symptom followed by visual compromise. Calcifications were present in 19.5% (n = 17) of the lesions.

CONCLUSIONS

This systematic review provides insights into the epidemiological, clinical, and neurosurgical characteristics, as well as the long-term prognosis of CA. This marks the first case in the reviewed literature with a 19-year period of follow-up where the patient had reoperation due to disease progression.

Amyloids and brain cancer: molecular linkages and crossovers

Amyloids are high-order proteinaceous formations deposited in both intra- and extracellular spaces. These aggregates have tendencies to deregulate cellular physiology in multiple ways; for example, altered metabolism, mitochondrial dysfunctions, immune modulation, etc. When amyloids are formed in brain tissues, the endpoint often is death of neurons. However, interesting but least understood is a close connection of amyloids with another set of conditions in which brain cells proliferate at an extraordinary rate and form tumor inside brain. Glioblastoma is one such condition. Increasing number of evidence indicate a possible link between amyloid formation and depositions in brain tumors. Several proteins associated with cell cycle regulation and apoptotic pathways themselves have shown to possess high tendencies to form amyloids. Tumor suppressor protein p53 is one prominent example that mutate, oligomerize and form amyloids leading to loss- or gain-of-functions and cause increased cell proliferation and malignancies. In this review article, we present available examples, genetic links and common pathways that indicate that possibly the two distantly placed pathways: amyloid formation and developing cancers in the brain have similarities and are mechanistically intertwined together.

Cerebral Amyloidoma Accompanied by Sjögren's Syndrome: A Case Report and Literature Review

We present a 69-year-old woman with colorectal cancer and a left frontal lobe tumor that was diagnosed as a cerebral amyloidoma after surgical resection. Further postoperative systemic evaluation revealed another amyloidoma in her hip as well as Sjögren's syndrome. Systemic amyloidosis was not present. To the best of our knowledge, this is the first case of cerebral amyloidoma presenting as one of the multiple localized amyloidomas accompanied by Sjögren's syndrome. We also present a systematic review of 65 cerebral amyloidoma cases reported in the literature over the past 40 years and discuss patient characteristics and pathological and imaging findings associated with prognosis.

Minimally Invasive Resection of Intracerebral Amyloidoma: Case Report and Systematic Review of the Literature

BACKGROUND

Management of cerebral amyloidomas has lacked consensus owing to their rarity. We present a case and review 39 reported cases of amyloidomas in the literature, comparing their initial presentation, imaging characteristics, treatment, and progression.

CASE DESCRIPTION

A 56-year-old woman presented with a history of intractable headaches and progressive speech difficulty. Imaging demonstrated a 1.7 × 2.6 cm left frontal subcortical hemorrhagic mass with an associated developmental venous anomaly, characteristics initially suggestive of a cavernous malformation. Diffusion tractography imaging was employed to avoid interference with the intact arcuate fasciculus and corticospinal tracts to minimize neurologic deficits.

CONCLUSIONS

To our knowledge, this is the first documented case of the use of diffusion tractography in preoperative planning for cerebral amyloidoma resection. Our systematic review of 39 reported cases of amyloidomas in the literature provided insight regarding how these rare lesions have manifested and progressed and further understanding of current theories regarding their etiology and pathophysiology. Cerebral amyloidomas are rare, localized, proteinaceous aggregates with variable presentation and prognosis and no apparent relationship to systemic amyloidosis. Biopsy may be useful in determination of progression. Diffusion tractography is a valuable tool for minimizing complications associated with resection.

A 61-year-old man with instability of gait and right hand clumsiness

60 year-old man, without relevant medical history, noted a slight and progressive instability of gait for one month and right hand clumsiness. Brain MRI showed a cerebellar lesion, posterior to the middle cerebellar peduncle. This lesion was heterogeneous and hyperintense on FLAIR sequences, isointense on T1-weighted images, and showed gadolinium enhancement. Hematological and biological serum analyses were normal as were plasma and urine immunoelectrophoresis. CSF analysis including protein electrophoresis was unremarkable. CT scans of the abdomen, chest and pelvis were normal as were cervical echography and bone scintigraphy. A yellowish and firm lesion was surgically resected. The patient's recovery was good, with normal total body PET scan and bone marrow biopsy. Pathological study evidenced kappa light chain deposits and kappa-immunopositive mature plasma-cells in the vicinity. The deposits failed to show any birefringence in polarized light microscopy after Congo red staining, and electron microscopy revealed their granular ultrastructure. Light chains are well known for their amyloidogenic properties, but in a few cases, they are non amyloidogenic and may cause tissue deposits histologically similar to amyloid but Congo red-negative and non fibrillary at ultrastructural examination. Occurrence of light chain deposits in the brain is rare and the tumor-like MRI presentation is reminiscent of primary intracerebral amyloidoma presenting as a mass lesion. This is the first report of intracerebral kappa light chain deposits which presumably derived from local synthesis by mature plasma cells.