A case study recently reported that an asymptomatic 12-year-old boy was diagnosed with a solitary cutaneous mastocytoma in a rare case.

Cutaneous Mastocytosis

Cutaneous mastocytosis affects the skin, causing small flat brownish spots that are made more obvious by scratching. For children under the age of three, blistering of these lesions can occur. Cutaneous mastocytosos can evolve into many different subtypes, including maculopapular, dodular, and diffuse cutaneous mastocytosis (DCM), which is the most severe form and usually presents itself during childhood. DCM causes the skin to thicken and become discolored, and other symptoms include blistering, low blood pressure, gastrointestinal bleeding, itchiness, diarrhea, and anaphylactic shock.

Cutaneous Mastocytoma

Mastocytoma is the name given to a form of cutaneous mastocytosis in which there is a dermal accumulation of mast cells forming one to three solitary lesions.

Typical characteristics of mastocytoma are:

• A firm, macule or indurated plaque 1–5 cm in diameter
• The surface may be pitted (peau d’orange appearance)
• Red, pink, yellow or brown in colour
• Intermittent itching, especially when rubbed
• Rubbing causes the lesion to urticate (redden and swell) for 15 minutes or so (a positive Darier sign). A blister may also occur.

The Case

A twelve-year-old boy had a reddish-brown cutaneous lesion on his chest that was increasing in size at a fairly rapid speed. He had no other lesions on his body and presented without any symptoms, and after a number of scans he did not appear to have any abnormalities.

The lesion was then surgically removed and sent for a histopathologic examination. The examination showed the boy’s underlying dermis had a dense infiltrate of oval cells that contained a great deal of granular cytoplasm. They were then confirmed to be mast cells, and the boy was diagnosed with asymptomatic solitary cutaneous mastocytoma.

What to Look for with Solitary Cutaneous Mastocytosis (SM)

In most cases, SM is found during infancy and there are very little cases of it appearing in children over the age of two. When looking into a diagnosis, doctors take family history into consideration.

The signs and symptoms of SM can be triggered by a number of things such as physical stimuli (for example heat, cold, friction, etc.), emotional factors, certain drugs, and more. Symptoms can include localized blistering, flushing, vomiting, diarrhea, weight loss, and so on. If a patient experiences both the physical appearance and symptoms, they should talk to their doctor as soon as possible.

To manage SM, doctors look to prevent mediator release. They do this through prescribing antihistamines, cromolyn sodium, aspirin, and a strong recommendation to avoid triggering factors. Some topical treatments may also be prescribed.