Telangiectasia macularis eruptiva perstans (TMEP) is a rare, heterogeneous disease of mast cell proliferation. The variable clinical presentation of TMEP, coupled with its rarity, makes the recognition and diagnosis of this disease difficult and challenging for clinicians. The histopathologic findings with hematoxylin and eosin staining that distinguish TMEP from a normal skin biopsy can be so subtle that confirmation of the diagnosis with additional special stains (c-Kit, Giemsa, toluidine blue) is strongly recommended. We describe three cases that highlight the variable clinical presentation of TMEP. One patient experienced only a localized skin manifestation, another an aggressive clinical course with systemic involvement, and a third diffuse skin involvement with mild fatigue, muscle pain, and weight gain.

A 26-year-old African American woman with a history of a recurring "oozing papule" in the right ear presented to the emergency department in July 2010 with a 2-month history of an enlarging, painful growth in the right ear canal. Physical examination revealed a 1-cm round cystic lesion along the right, anterior external auditory canal wall, just medial to the tragus. Initial diagnosis was an infected cyst of the external ear canal. The patient was instructed to follow-up with an ear, nose, and throat (ENT) office. Two months following the emergency department visit, inspection by ENT revealed a 3- to 4-mm round, firm subcutaneous nodule that did not extend into the ear canal or cartilage. According to the patient, this lesion had recurred with several infections. The lesion was biopsied in the outpatient setting and demonstrated ulceration with marked acute and chronic inflammation in addition to granulation tissue. Two months later, the lesion was surgically excised. The final diagnosis of giant cell tumor, tenosynovial type with lesion-free margins, and no involvement of the cartilage was made (Figures 1-3). No further treatment was recommended. Gross examination of the excised lesion revealed tan to white soft tissue measuring 1.0×0.7×0.3 cm. Results from factor XIII A immunostain was negative, confirming that the lesion did not represent an unusual variant of fibrous histiocytoma (Figure 4). To date, recurrence of this lesion has not been appreciated.

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.