Telangiectasia macularis eruptiva perstans: more than skin deep

Abstract

Systemic mastocytosis is a rare disease involving the infiltration and accumulation of active mast cells within any organ system. By far, the most common organ affected is the skin. Cutaneous manifestations of mastocytosis, including Urticaria Pigmentosa (UP), cutaneous mastocytoma or telangiectasia macularis eruptive perstans (TMEP), may indicate a more serious and potentially life-threatening underlying disease. The presence of either UP or TMEP in a patient with anaphylactic symptoms should suggest the likelihood of systemic mastocytosis, with the caveat that systemic complications are more likely to occur in patients with UP. TMEP can usually be identified by the typical morphology, but a skin biopsy is confirmative. In patients with elevated tryptase levels or those with frequent systemic manifestations, a bone marrow biopsy is essential in order to demonstrate mast cell infiltration. Further genetic testing for mutations of c-kit gene or the FIP1L1 gene may help with disease classification and/or therapeutic approaches. Rarely, TMEP has been described with malignancy, radiation therapy, and myeloproliferative disorders. A few familial cases have also been described. In this review, we discuss the clinical features, diagnosis and management of patients with TMEP. We also discuss the possible molecular pathogenesis and the role of genetics in disease classification and treatment.

Keywords: D816V mutation.; SCORMA index; mastocytosis; serum tryptase; telangiectasia macularis eruptiva perstans.

Figure 1

(A) Spontaneous telangiectasia macularis eruptiva perstans macular eruption. (B) Magnified view of the skin manifestations with small tan macules and red brown streaking. Images are produced with permission of the patient. (C) A cellular infiltrate is concentrated around superficial dermal blood vessels. Hematoxylin and eosin stain. 200× magnification. (D) The infiltrate demonstrates a substantial mast cell component (>15 per perivascular high power field). Many more mast cells are present than could be appreciated on the H&E-stained section. Mast cell tryptase immunohistochemical stain. 200× magnification.

Figure 2

Flow cytometry used to detect c-kit mutation. Both non-mutated peaks (A) and mutated peaks (B) were present in the patient. All patients with the c-kit mutation associated with mastocytosis should have some unmutated DNA present. These figures were kindly provided by Dr. Rebecca F. McClure of Mayo Clinic, Rochester, Minnesota.

Figure 3

Schematic diagram of c-kit tyrosine kinase receptor. The most common mutations, particularly the D816V mutation, that result in mastocytosis affect this specific protein on mast cells.