Discovery of a letter from Rokitansky to Virchow about subependymal corpora amylacea

Lung endothelium, tau, and amyloids in health and disease

Lung endothelia in the arteries, capillaries, and veins are heterogeneous in structure and function. Lung capillaries in particular represent a unique vascular niche, with a thin yet highly restrictive alveolar-capillary barrier that optimizes gas exchange. Capillary endothelium surveys the blood while simultaneously interpreting cues initiated within the alveolus and communicated via immediately adjacent type I and type II epithelial cells, fibroblasts, and pericytes. This cell-cell communication is necessary to coordinate the immune response to lower respiratory tract infection. Recent discoveries identify an important role for the microtubule-associated protein tau that is expressed in lung capillary endothelia in the host-pathogen interaction. This endothelial tau stabilizes microtubules necessary for barrier integrity, yet infection drives production of cytotoxic tau variants that are released into the airways and circulation, where they contribute to end-organ dysfunction. Similarly, beta-amyloid is produced during infection. Beta-amyloid has antimicrobial activity, but during infection it can acquire cytotoxic activity that is deleterious to the host. The production and function of these cytotoxic tau and amyloid variants are the subject of this review. Lung-derived cytotoxic tau and amyloid variants are a recently discovered mechanism of end-organ dysfunction, including neurocognitive dysfunction, during and in the aftermath of infection.

Focus on localized laryngeal amyloidosis: management of five cases

Amyloidosis is a group of idiopathic clinical syndromes caused by the deposition of insoluble fibrillar proteins (amyloid) in the extracellular matrix of organs and tissues. These deposits disrupt the function of the target organ. Amyloidosis can manifest as a systemic disease or a single-organ involvement (local form). Its etiology still remains unclear. Deposits of amyloid in the larynx are rare, accounting for between 0.2 and 1.2% of benign tumors of the larynx. In this retrospective study, we report the clinical aspects, diagnosis, treatment and follow-up of five female patients with localized laryngeal amyloidosis without systemic involvement. The patients were all treated successfully using microlaryngoscopy with CO₂ laser or cold instruments. Prognosis is excellent; however, appropriate follow-up is an important part of the long-term management of this disease in order to prevent and control the possibility of local recurrence.

Parahippocampal corpora amylacea: case report

OBJECTIVE

Corpora amylacea (CA) normally accumulate within perivascular, subpial, and subependymal astrocytic processes. CA are associated with a number of conditions including normal aging, hippocampal sclerosis associated with temporal lobe epilepsy, multiple sclerosis, Lafora-type progressive myoclonic epilepsy, and adult polyglucosan body disease. Reports of massive localized accumulation of CA in the brain outside of these conditions are rare.

CLINICAL PRESENTATION

A 49-year-old woman, with a long-standing history of migraine headaches, presented to her primary care provider for increased headache duration. Brain magnetic resonance imaging (MRI) revealed a left parahippocampal lesion, suggestive of low-grade glioma.

INTERVENTION

Given the MRI suggestive of left parahippocampal glioma, left-sided frontotemporal craniotomy was performed for resection of the lesion. Specimens obtained during the operation revealed focal high-density accumulation of CA with no evidence of neoplasm, ischemia, or hypoxic injury.

CONCLUSION

This case illustrates the possibility that localized high-density CA accumulation can present as an intrinsic lesion on brain MRI. CA should be included in the differential diagnosis for patients presenting with brain MRI suggestive of nonenhancing space-occupying lesions.