Patients with mastocytosis are characterized as having either systemic mastocytosis (SM) or cutaneous mastocytosis (CM). Patients with SM exhibit bone marrow, liver, spleen, or gastrointestinal tract involvement, whereas those with CM experience a proliferation and accumulation of mast cells in their skin.
CM is divided into 3 main types: 1) maculopapular cutaneous mastocytosis (MPCM), 2) diffuse cutaneous mastocytosis, and 3) solitary mastocytoma. MPCM is further divided into the following subtypes: 1) papular/plaque variants, 2) urticaria pigmentosa, and 3) telangiectasia macularis eruptiva perstans (TMEP).
A CM diagnosis is verified via dermal infiltration of mast cells or by using special stains. TMEP, which is a rare variant of CM, is reported in fewer than 1% of patients. A TMEP diagnosis is typically based on clinical findings and histologic examination, with the final diagnosis rendered via immunohistochemistry with tryptase and the transmembrane protein c-kit.
The current case report, which was published in the Journal of the Turkish Academy of Dermatology, describes a 51-year-old man with TMEP. The case study concentrates on dermoscopic, histopathologic, clinical, and immunohistochemical findings.
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Over the last 11 years, the patient had been experiencing an erythematous rash on his back, chest, and arms. His skin lesions usually would improve within several months, subsequently resulting in the development of hyperchromic lesions. The man did not reported any itchiness, fever, bone pain, muscle pain, abdominal pain, diarrhea, syncope, weight loss, or oral ulcers.
Treatment, which included antiallergic/antihistamine tablets and corticosteroid cream, had not been associated with any improvement. The patient did not report any personal or family history of any allergies.
According to the results of histopathologic analysis, edema was observed in the superficial dermis, with inflammatory cells containing lymphocytes and mast cells in the perivascular, periadnexal, and telangiectatic veins. Ultimately, the patient was diagnosed with TMEP, for which he received treatment with 10 mg of cetirizine once daily and 1 mg of ketotifen twice daily.
He was advised to avoid any histamine-containing agents, including alcohol, aspirin, nonsteroidal anti-inflammatory drugs, and anticholinergic agents, as well as heat, friction, and opioids. Although the patient exhibited improvement with use of the prescribed medications, further assessment was warranted to determine the presence of any systemic disease involvement—that is, SM.
Among individuals with TMEP, the molecular pathogenesis of disease remains to be elucidated, with a number of studies reporting point mutations in the KIT gene. KIT, which is a type III tyrosinase kinase that is expressed on mast cells and melanocytes, is a major growth factor of mast cells. Histopathologically, the mast cell infiltration observed among patients with TMEP is located mainly in the upper third of the dermis, typically clustering around dilated capillaries and superficial venule plexuses.
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In the current case, the TMEP diagnosis was based on the correlation among clinical manifestations, dermoscopic examination, immunohistochemistry, and histopathologic results. Small, irregular, reddish-brown telangiectatic macules on the predilection areas were reported on clinical findings, with dermoscopy results matching the pattern in this case. Biopsy findings revealed mast cell infiltration in the upper third of the dermis and around dilated capillaries, which was “highlighted by Giemsa and immunochemistry with CD117 staining.”
Most cases of TMEP are confined to the skin, but systemic involvement has been reported in 35% to 50% of cases within 6 or more years of onset.
The authors concluded, “Although the patient showed improvement with medication, further evaluation is needed to assess the possibility of systemic involvement.”
Suryawati N, Saputra H. Telangiectasia macularis eruptiva perstans: a case report and review literature. J Turk Acad Dermatol. Published online June 21, 2023. doi:10.4274/jtad.galenos.2023.27247