Nodular amyloidosis - Skin
In nodular amyloidosis, the amyloid deposits are found in the dermis and subcutaneous fat and within the walls of blood vessels. Clinically, the condition presents as brownish-pink waxy-appearing papules or nodules, occurring singly or in groups, most commonly on acral surfaces and the face. Involvement of the trunk, genitals, and extremities has also been reported. There can be telangiectasias or atrophy of the overlying epidermis.
Men and women are affected equally. The disease usually begins in middle age. Typically, the prognosis is quite good, although a small minority of people (less than 10%) progress to systemic amyloidosis. A significant number of cases of nodular amyloidosis have occurred in association with Sjögren's syndrome. For this reason, appropriate screening tests, routine physical examinations, and thorough histories to exclude connective tissue disease are often a priority.
E85.9 – Other amyloidosis
402462008 – Nodular amyloidosis
- Colloid milium – acquired colloid milium presents on sun-exposed surfaces of the elderly, while juvenile colloid milium occurs in young persons. The disease may resemble nodular amyloidosis both clinically and histologically. Electron microscopy may be utilized to discriminate between the conditions.
- Sarcoidosis – a disease chiefly of African Americans, sarcoidosis, particularly when it occurs upon the face (lupus pernio), may mimic nodular amyloidosis. The distinction is quite clear by biopsy, as sarcoid is a granulomatous rather than depositional disease.
- Leiomyoma – often presents as agminated (clustered) lesions of smooth muscle on the face that characteristically cause pain when exposed to cold (because of contracture). Biopsy easily distinguishes between the two conditions.
- Cutaneous pseudolymphoma / lymphocytoma cutis – this condition, caused by recapitulation of lymph node-like tissue in the skin, is easily distinguished by biopsy.
- Basal cell carcinoma – a ubiquitous sun-induced non-melanoma skin cancer, common on the face of middle-aged to elderly individuals and often associated with a waxy appearance and telangiectasias, similar to nodular amyloidosis. The condition is easily distinguished by biopsy.