Histopathological findings in patients with lipoid proteinosis

Objective: Lipoid proteinosis (LP) is a rare autosomal recessive genodermatosis characterized by the accumulation of amorphous hyaline substance in the skin and mucous membranes. In this study, the histopathological findings of the patients who were admitted to our clinic and diagnosed with LP were examined. Materials and Methods: This prospective study included 18 patients who presented to our clinic between January 2014 and December 2018 and were confirmed by histopathological examination. A punch biopsy including epidermis, dermis, and subcutaneous tissues was obtained from the lesional skin of each patient evaluated clinically, and the material was stained with hematoxylin and eosin stain and periodic acid–Schiff (PAS) stain. These preparations were evaluated by a pathologist experienced in dermatopathology. Results: The most common histopathological findings in the epidermis were hyperkeratosis (88.8%) and pigmentary incontinence (83.3%) in the basal layer. The most common histopathological findings in the dermis were amorphous substance accumulation (100%), perivascular PAS positivity (33.3%), and PAS positivity around eccrine glands (11.1%). Conclusion: The findings of our study were similar to the histopathological findings of late-term skin lesions in LP patients previously described in the literature. In order to better understand the histopathological findings of skin lesions of LP patients, studies with a large number of patients including early skin lesions of LP are needed.