10038 - Blue Nevus and Blue Nevus-like Lesions: Benign and Malignant

Course Director

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


Dermal-based melanocytic proliferations with dendritic/spindle cell cytomorphology and melanin production give rise to clinical lesions with a distinctive blue-black hue. The common blue nevus is relatively straightforward histologic diagnosis, however variant lesions such as cellular blue nevi, cellular blue nevi with cytologic atypia, plaque-like blue nevi, neurocristic hamartoma, pigmented epithelioid melanocytoma, and cellular blue nevi with malignant transformation can represent significant diagnostic challenges. These are not common lesions with limited representation of their pathologic features available in published textbooks. This course is designed to elucidate diagnostic and key differentiating features of this series of lesions.


AMA PRA Category 1 Credits™

Opus Medicus designates this Internet enduring material for a maximum of 1.25 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:

1.25 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: $32.50

Course Dates

Last Review Date: 18-Oct-2021
Expiration Date: 17-Oct-2024


1. Develop familiarity with benign common and cellular variants of blue nevi.

2. Understand criteria for applying the term "atypical" to cellular blue nevus and need to ensure complete removal of these lesions.

3. Learn how to differentiate plaque-type blue nevus, diffuse neurofibroma, pilar neurocristic hamartoma, and desmoplastic melanoma.

4. Learn the characteristics of epithelioid blue nevi and pigmented epithelioid melanocytoma.

5. Learn the uses of the term "malignant blue nevus", criteria for diagnosis, and differentiation from benign cellular blue nevus.


1. Background/Tyndall effect

2. Common Blue Nevus and Variants

3. Dermal Melanocytoses

4. Cellular Blue Nevus

5. Atypical Cellular Blue Nevus

6. Plaque-type Blue Nevus

7. Pilar Neurocristic Hamartoma

8. Epithelioid Blue Nevus

9. Pigmented Epithelioid Melanocytoma

10. Malignant Blue Nevus

Specific topics covered in this AMA PRA Categogy 1 Credit™ online CME course include blue nevus, Tyndall effect, nevus of Ota, nevus of Ito, Mongolian spot, cellular blue nevus, atypical cellular blue nevus, plaque-like blue nevus, pilar neurocristic hamartoma, pigmented epithelioid melanocytoma, malignant blue nevus, and diffuse neurofibroma.

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 the commercial entities with which he has relationships do not produce health-care related products or services relevant to the course content. 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 produce health care-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 1.25 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.