Primary Localized Cutaneous Nodular Amyloidosis on Scalp Successfully Treated with Excision

Primary localized cutaneous nodular amyloidosis (PLCNA) is the rarest form of cutaneous amyloidosis, characterized by nodular deposits of light chain amyloids in the dermis and subcutaneous tissue, without apparent systemic involvement. One or several nodules are preferably located on the extremities, trunk, or face. The most useful stain for detecting amyloid fibrils is Congo red, which, when combined with polarized light, makes amyloid proteins appear apple-green under a microscope. Immunohistochemical staining can help identify the exact type of amyloid proteins. Although the exact etiology of PLCNA is unclear, removal of nodules by shaving or surgical excision has shown good results. To the best of our knowledge, only seven cases of PLCNA have yet been reported in the Korean literature. In three of these cases, the patients had lesions on the scalp. Herein, we present a case of a 34-year-old male with PLCNA on the scalp with all the results of immunohistochemical evaluation.