Mastocytoma

LAST UPDATED: Nov 18, 2021

Introduction

A mastocytoma is a localised form of an uncommon group of conditions known as ‘mastocytosis’, which are characterised by a local or diffuse, increased growth and accumulation of mast cells in the skin and / or internal organs, especially the bone marrow and gastrointestinal tract.

This chapter is set out as follows:

History
Clinical findings
Images
Management

History

Most cases of mastocytoma arise in early childhood
Lesions are usually asymptomatic
Systemic involvement, with symptoms such as flushing or abdominal pain, is rare

Clinical findings

Distribution

Any site can be affected

Morphology

One or more smooth, red-yellow plaques / nodules
Size varies from 1-5 cm in diameter
Darier's sign - lesions urticate (become red and swollen), and occasionally blister, within a few minutes of gentle rubbing

Clinical Images

Please refer to notes on image rights at bottom of the page with regards to individual image ownership.

Management

Nearly all lesions will resolve in the first few years of life

Treatment is not normally needed, although non-sedating antihistamines can be used if itch is prominent

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Image Rights - The PCDS would like to thank Dermatoweb, DermQuest (Galderma), and others who have contributed images. All named individuals and organisations maintain copyright for the relevant images.