Asymptomatic, Red-Brown Macules Symmetrically Distributed on the Trunk and Arms of Adult Male Patients.

Abstract

DISCUSSION Telangiectasia macularis eruptiva perstans (TMEP) is a rare presentation of cutaneous mastocytosis seen most commonly in adults. TMEP typically presents as symmetrically distributed red-brown telangiectatic macules with irregular borders on the trunk and accounts for less than 1%–14% of all presentations of cutaneous mastocytosis.1,2 The cutaneous lesions are typically asymptomatic, but may be pruritic. In 2 case series, 47%–67% of patients with TMEP were found to have systemic mastocytosis.2,3 With multifocal aggregates of .15 mast cells per high power field in our patient’s most recent bone marrow biopsy, of which greater than 25% exhibited spindled morphology, along with a persistently elevated serum tryptase level, he met diagnostic criteria for systemic mastocytosis.4 The clinical diagnosis of TMEP may be more challenging than other forms of cutaneous mastocytoses. Darier’s sign is a physical examination finding where mechanical irritation, such as rubbing or stroking, causes an urticaria-like wheal. This is seen in most forms of cutaneous mastocytosis but is typically negative in TMEP.2 The clinical differential diagnosis includes vascular entities such as generalized essential telangiectasia and angioma serpiginosum, as well as inflammatory disorders such as lichen planus pigmentosusinversus. Our patient had previously been evaluated for brown macules without background telangiectasias on the trunk with a favored clinical diagnosis of lichen planus pigmentosus-inversus. Subtle clinical findings may also mimic benign lentigines. Histopathologic examination is necessary to confirm the diagnosis. The histopathologic changes seen in cutaneous mastocytosis can be subtle, and mast cells may have a spindled morphology.5 Special stains such as Leder stain, Giemsa stain, and Toluidine blue are used to highlight mast cells located in the upper third of the dermis and around the capillaries.5 Immunohistochemistry with CD117 and tryptase can also be helpful in locating mast cells in difficult cases. There is no gold standard therapy for cutaneous mastocytosis; therefore, treatment is tailored toward symptom management. Topical medications include corticosteroids and calcineurin inhibitors. Second-generation antihistamines, such as fexofenadine, cetirizine, and loratadine, may be used to control symptoms associated with mastocytosis along with other mast cell stabilizers such as cromolyn sodium. Psoralen plus ultraviolet A (PUVA) may be used but is typically reserved for severe cases.5 It is also important to counsel on potential triggers of mast cell stimulation. These include physical stimuli such as pressure, friction, extremes in temperatures, and chemical mast cell degranulators including aspirin, opioids, and alcohol. After the diagnosis of cutaneous mastocytosis, particularly in an adult, a thorough review of systems and evaluation for systemic involvement should be performed. Systemic involvement may manifest as systemic mastocytosis or less commonly, as an associated non–mast cell hematologic disorder, as was initially seen in our patient.6 Serum tryptase is a useful marker to screen for systemic mastocytosis, as tryptase is found within mast cell granules and is an indicator of total mast cell burden. Serum tryptase levels over 20 ng/mL are typically seen in patients with systemic mastocytosis.7 Although TMEP is not considered a separate entity in the World Health Organization (WHO) classification of cutaneous mastocytosis, it remains an important clinical and pathologic entity, given that more than 50% of patients may have systemic involvement.2,3,7,8 Our case represents a presentation of TMEP in an adult patient with systemic mastocytosis and myelodysplastic disorder, which is categorized by the WHO as a systemic mastocytosis associated with a hematologic non–mast cell lineage disease.4 Although a recent case of myelofibrosis with a 5q deletion and cKIT-positive mastocytosis has been reported, a 5q deletion was not found in our patient.9,10 This case also warrants sociocultural consideration, as our patient is a Jehovah’s Witness. Owing to his religious affiliation, a bone marrow transplant was not pursued for myelofibrosis. With a known JAK2 V617F-positive myelofibrosis, our patient is currently managed with ruxolitinib, a JAK 1/2 inhibitor, fexofenadine 180 mg orally twice per day, and cromolyn sodium 200 mg orally 4 times per day. Although ruxolitinib has been used to treat our patient’s From the *SAUSHEC—Dermatology, Fort Sam Houston, TX; and Departments of †Dermatology, and ‡Pathology, SAUSHEC, Fort Sam Houston, TX. The authors declare no conflicts of interest. Correspondence: Emily Maxon, DO, SAUSHEC—Dermatology 3551 Roger Brooke Dr, Fort Sam Houston, TX 78234 (e-mail: [email protected]). Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.