Extensive Cutaneous Mastocytosis After Pregnancy

Abstract

Mastocytosis is an uncommon disease involving the proliferation of mast cells within at least one organ system, most commonly the skin. One rare variant is telangiectasia macularis eruptive perstans (TMEP). The telangiectatic tan-brown macules are highly characteristic, although a biopsy is indicated to confirm the diagnosis. We present a 33-year-old white woman who presented for a skin check with concern for a four- to six-year history of "moles" present on the majority of body surface area. Her lesions presented shortly after her first pregnancy and spared sun-exposed face, neck, and extremities. Both of these features are rather unusual in TMEP. In this asymptomatic patient, workup focused on excluding systemic manifestations and discussion of cosmetic treatments. Punch biopsies revealed nests of CD117+ mast cells as well as increased basal melanocytes. Because the lesions spared sun-exposed regions, sunbathing was advised for initial treatment.

Keywords: mastocytosis; pregnancy; tmep.

Figure 1. (A) Multiple non-coalescing brown macules on the upper and lower back. (B) Closer view of the skin findings in detail.

Figure 2. (A) Dermatoscopic evaluation of a mildly pigmented macule with poorly defined margins. (B) Dermatoscopic evaluation of a deeply pigmented macule with sharper margins.

Figure 3. CD117+ stain showing mast cells in the dermal layer.

Figure 4. Higher power magnification reveals nests of mast cells (arrows).