Abstract
Abstract 5176
Introduction
Telangiectasia macularis eruptiva perstans (TMEP) is a rare form of cutaneous mastocytosis seen commonly in adults. TMEP may show systemic manifestations and may be associated with myelodysplasia, myeloproliferative disorders, acute myeloid leukemia, and/or lymphoproliferative disease, but is not well recognized by hematologists. We present two cases of this rare but fascinating disease that illustrate the wide range of associated findings that may be present.
Case 1
A 73-year-old female presented with hyperpigmented patches on her thighs, knees, and ankles/dorsal feet. She had no systemic symptoms. Skin biopsy showed dilated vessels and associated mast cells indicative of TMEP. A toluidine blue stain highlighted increased mast cells around the superficial vessels in the papillary dermis. Some mast cells in the superficial dermis also showed c-kit immunoreactivity. After four years she is still asymptomatic and no further studies have been performed.
Case 2
A 28-year-old female presented to a doctor's office with a three day history of oral labial edema with burning and pruritus. She took Benadryl at home and also received Benadryl injection without relief. She had lesions on her forehead that spread to involve the remainder of her body, lasting from five minutes to hours. She also experienced flushing, dizziness, tinnitus, dyspnea, wheezing, cough, arthralgia and daily abdominal cramps with diarrhea. She was referred for bone marrow biopsy and further evaluation, and was diagnosed with TMEP on skin biopsy. The diagnosis was confirmed with positive toluidine blue and Giemsa stains and c-kit immunoreactivity. She had no bone marrow involvement.
Case 3
A 36 old female presented with a rash for over a year. It initially started on her face and then spread to the chest, upper arms and hands. It was focally pruritic and painful. She also complained of fatigue, muscle pain on the shoulders and weight gain. Physical examination showed diffuse scattered telengiectasias of the face, upper palate, buccal- labial mucosa, neck, upper chest, upper arms, palms and fingers. A skin biopsy revealed dilated blood vessels and increased mast cells in the superficial dermis. Toluidine blue and Giemsa stains demonstrated the mast cells and the c-kit immunostain was also reactive.
Cutaneous mastocytosis is a mast cell proliferative disorder with at least four different clinical forms: urticaria pigmentosa, solitary mastocytoma, diffuse cutaneous mastocytosis, and TMEP. In TMEP, characteristically, lesions are ill defined, non-pruritic, but urticate on rubbing, telengiectatic tan/brown 2–6 mm macules located symmetrically over the trunk and extremities and rarely on the face. Occasionally, urticaria pigmentosa may coexist with this lesion; however TMEP should be distinguished from urticaria pigmentosa with overlying telangiectases. Darier's sign is usually absent or minimal. This is because the lesions are characteristically paucicellular, and the few mast cells may not yield significant degranulation to exhibit Darier's sign and dermographism. Symptoms are the result of degranulation of mast cells with the release of multiple mediators. Flushing, blistering, pruritus, cardiac arrhythmias, dyspnea, asthma exacerbations, hypotension, gastrointestinal upset, acid reflux, peptic ulcer disease, diarrhea, splenomegaly, increased numbers of mast cells in the bone marrow, abnormal skeletal radiographs, irritability and nonspecific neuropsychiatric symptoms can be seen.
TMEP is characteristically composed of subtly increased numbers of ovoid to spindle shaped mast cells infiltrating the papillary dermis and surrounding dilated superficial capillaries and venules. To distinguish mast cells from histiocytes, Giemsa and toluidine blue stains are useful. Tissue sections showing more than 5–10 mast cells are confirmatory for the diagnosis. c-Kit immunohistochemistry can be used to confirm the diagnosis. c-Kit is a proto-oncogene that codes for a tyrosine kinase receptor (CD117) present on mast cells and melanocytes.
The present cases illustrate the wide diversity of systemic manifestations of mastocytosis that may accompany TMEP. Case one showed no systemic signs at all, whereas cases two and three showed significant systemic disease. In case three lesions started on the face, an unusual location for TMEP. Appropriate work-up is mandatory in cases presenting with TMEP.
Disclosures:
No relevant conflicts of interest to declare.
Diffuse Cutaneous Mastocytosis (Pigmented Maculopapular Cutaneous Mastocytosis) in a Cat
