Related Experiment Video
Updated: May 10, 2026

Intradermal Inoculation of Mycobacterium avium in the Mouse Ear
Published on: July 3, 2025
Verruciform xanthoma of the earlobe in an immunosuppressed patient
Bishr Aldabagh1, Amir Al-Dabagh, Arif S Usmani
1Department of Dermatology, Duke University Medical Center, Durham, North Carolina, USA. bishbish07@yahoo.com
Abstract:
Verruciform xanthoma (VX) is an uncommon mucocutaneous lesion of uncertain etiology. Originally thought to be limited to the oral mucosa, its occurrence in other mucosal and nonmucosal sites also has been documented. Histologically, VX is characterized by subepithelial foamy histiocytes associated with papillomatosis, parakeratosis, and dyskeratosis. Subepithelial foamy cells are lipid-containing, non-Langerhans cell histiocytes. A variety of etiologies have been proposed without much consensus, including infectious (bacterial, viral, and fungal), degenerative, reactive/ reparative, inflammatory, metabolic, reactive/ multifactorial, and immunosuppressive factors. Verruciform xanthoma of the external ear is exceedingly rare. Herein, we report a rare case of VX occurring on the earlobe at a piercing site in an immunosuppressed patient and provide a discussion of the possible pathogenetic mechanism(s).
Related Concept Videos
Pulmonary Tuberculosis I
Causative Organism
The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare.
Mode of...
Endocarditis II: Clinical Features of Infective Endocarditis
Skin Diseases and Disorders
Gram-positive Staphylococcus spp. and Streptococcus spp. are responsible for many of the most common skin infections. However, many...