A gastric biopsy from a patient with dyspepsia and a history of acne.

Diagnosis: Injury of the type associated with doxycycline medication. Note the peculiar fibrinoid change in the tiny vessels beneath the surface.

Shih AR, Lauwers GY, Mattia A, Schaefer EA, Misdraji J. Vascular Injury Characterizes Doxycycline-induced Upper Gastrointestinal Tract Mucosal Injury. Am J Surg Pathol. 2017;41(3):374-381.