DERMATOPATHOLOGY DIAGNOSIS Tetrad Bodies in Skin Aadil Ahmed, MD Eligible for 1 MOC SA Credit From the ABD This Dermatopathology Diagnosis article in our print edition is eligible for 1 self-assessment credit for Maintenance of Certification from the American Board of Dermatology (ABD). After completing this activity, diplomates can visit the ABD website (http://www.abderm.org) to self-report the credits under the activity title “Cutis Dermatopathology Diagnosis.” You may report the credit after each activity is completed or after accumu- lating multiple credits. A 72-year-old woman with a medical history notable for multiple sclerosis and intravenous drug abuse presented to the dermatology clinic with a 0.6×0.5-cm, pruritic, wartlike, inflamed, keratotic papulecopy on the palmar aspect of the right finger of more than 1 month’s duration. A shave biopsy was performed that showed exco- riation with serum crust, parakeratosis, and neu- trophilicnot infiltrate in the papillary dermis. Within the serum crust and at the dermoepidermal junction, clusters of refractive basophilic bodies (arrows) in tetrad arrangement also were noted Do(inset). The papule resolved after the biopsy without any additional treatment. H&E, original magnifications ×40 and ×1000 (inset). THE BEST DIAGNOSIS IS: a. bacterial infection b. Demodex mite CUTIS c. foreign body d. fungal infection e. urate crystals PLEASE TURN TO PAGE 164 FOR THE DIAGNOSIS From the Department of Pathology and Laboratory Medicine, Loyola University Medical Center, Maywood, Illinois. The author reports no conflict of interest. Correspondence: Aadil Ahmed, MD, Department of Pathology and Laboratory Medicine, Loyola University Medical Center, 2160 S First Ave, Maywood, IL 60153 (
[email protected]).