Home   Chapter Home   Jobs   Conferences   Fellowships   Books



Advertisement

Skin - Nonmelanocytic tumors

Benign nonmelanotic epidermal tumors / tumor-like lesions

Melanoacanthoma


Reviewer: Christopher Hale, M.D. (see Reviewers page)
Revised: 25 June 2012, last major update June 2012
Copyright: (c) 2001-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● May be a pigmented variant of seborrheic keratosis
● Benign; cutaneous and oral variants, also called “melanoepithelioma”

Case reports
=========================================================================

● 65 year old man with “giant variant” melanoacanthoma (Indian J Dermatol 2011;56:79)

Clinical images
=========================================================================



Resembles melanoma

Gross description
=========================================================================

● Pigmented plaque, papule or nodule
● Dull surface

Micro description
=========================================================================

● Resembles seborrheic keratosis but with prominent, dendritic melanocytes with abundant melanin granules
● Melanocytes are scattered throughout the lesion
● No atypia

Micro images
=========================================================================



Basaloid cells form well-defined islands; numerous melanocytes are scattered throughout the lesion

Electron macroscopy description
=========================================================================

● Composed of benign keratinocytes and dendritic melanocytes, incomplete transfer of pigment from melanocytes to keratinocytes, normal population of Langerhan’s cells (J of Cutan Pathol 1978;5:127)

Differential diagnosis
=========================================================================

● Melanoma
● Pigmented malignant hidroacanthoma
● Pigmented squamous cell carcinoma
● Pigmented basal cell carcinoma

End of Skin - Nonmelanocytic tumors > Benign nonmelanotic epidermal tumors / tumor-like lesions > Melanoacanthoma


This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.

All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at copyrightPathOut@gmail.com with any questions (click here for other contact information).