Nodular amyloidosis presenting like a primary scarring alopecia.

Nodular amyloidosis (NA) is a rare type of primary localized cutaneous amyloidosis in which light chain amyloid deposits in the skin without concurrent systemic involvement. We report a challenging case of NA on the scalp, mimicking primary scarring alopecia, in a relatively young and healthy 36-year-old man. In addition to a nonspecific clinical appearance with a broad differential, NA can be a difficult diagnosis because it may require ancillary testing, such as liquid chromatography-tandem mass spectrometry to type the amyloid protein, and hematology-oncology workup to exclude systemic disease. Pathologists can highlight the importance of systemic evaluation in their reports to ensure patients receive appropriate management.