10049 - Ulcerating and Necrotizing (non-vasculitic) Skin Disorders: Histopathologic Keys to Clinical Correlations, a How-to Guide

Course Director

Steven R. Tahan, M.D., Harvard Medical School


This course addresses the need for recognition of critical differential diagnoses in skin specimens with the principle finding of ulceration and/or necrosis. It employs an algorithmic approach using microanatomic pattern to delineate a list of potential etiologies and elucidates key histopathologic features that enable identification of specific entities of clinical importance. Essential elements of the clinical context will be highlighted when required for further diagnostic differentiation.


AMA PRA Category 1 Credits™

Opus Medicus designates this Internet enduring material for a maximum of 2.0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Maintenance of Certification (MOC) Credits

In addition to AMA PRA Category 1 Credits™, Opus Medicus designates this course for Specialty Board MOC Program Credits:

2.0 ABP CC/MOC Credits1

Accreditation Statement

Opus Medicus is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.

Tuition Fees

Course & Credits: $52.00

Course Dates

Last Review Date: 04-Jan-2022
Expiration Date: 03-Jan-2025


After completing this course, participants will be able to:

1. Recognize key features present in a skin specimen with ulceration/necrosis to develop a specific list of differential diagnoses.

2. Understand optimal type and location of skin sample for best diagnostic yield.

3. Utilize patient demographics and clinical history, including information on underlying disorders, specific timeline of lesional development, lesional morphologic features, and anatomic site to enhance specificity of diagnosis.


1. How-to guide to evaluating skin specimens with ulceration and necrosis.

2. Types of necrosis.

3. Physical injuries.

4. Vascular insufficiency: histologic features of ischemia and vasculopathic disorders.

5. Herpes simplex and Varicella-Zoster.

6. Arthropod bites (inclusing tick and brown recluse spider)

7. Infections including ecthyma gangrenosum.

8. Necrobiosis lipoidica and necrobiotic xanthogranuloma.

9. Protothecosis.

10 Acanthamebiasis.

11.Pyoderma Gangrenosum.


13.Pancreatic fat necrosis.

14.Necrotizing fasciitis.

American Board of Medical Specialties (ABMS) / Accreditation Council for Graduate Medical Education (ACGME) Competencies

☑  Patient Care (PC)
☑  Medical Knowledge (MK)
☑  Practice-Based Learning (PBL)

Financial Relationship Disclosure and Content Attestation

Dr. Steven R. Tahan attests that commercial entities with which he has relationships do not offer healthcare related products or services relevant to the content of this course. No other person who has provided content for or who can influence the content of this course has disclosed financial relationships with commercial entities that offer healthcare-related products or services relevant to the course content.

There has been no commercial support for this course.

Supported Computer Hardware and Software Configurations2

Supported client computing platforms include:

A broadband Internet connection is required (e.g., cable, DSL, and 3G or 4G wireless). The course presentation is automatically scaled to the size of the display, from 800x480 pixels (minimum supported) to 1920x1200 pixels. On some smart phones, viewing courses may be tedious.

Supported browsers include:

Javascript, cookies, and popups must be enabled on your browser (which is the default configuration for most browsers).

1. Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to 2.0 CC/MOC credits for the American Board of Pathology (ABP) Continuing Certification (CC) / Maintenance of Certification (MOC) Program, in addition to AMA PRA Category 1 Credits™. Participants will earn CC/MOC credits equivalent to the amount of AMA PRA Category 1 credits claimed for the activity. Immediately upon course completion, Opus Medicus will submit participant completion information to ACCME for the purpose of granting ABP CC/MOC credit.

2. The course may also be viewable on other client computing platforms that comply with Internet standards. If you experience technical problems that prevent you from viewing the course, we will promptly issue a full refund upon request.