The lesional biopsy specimen, which was compared with one from unaffected skin, revealed dilated upper dermal vessels with a discrete perivascular cellular infiltrate with increased mast cell numbers (range, 10-20 per high-power field) on Giemsa staining. Routine blood tests (including serum tryptase levels), abdominal ultrasound, and bone scintigraphy revealed no abnormalities. There were significant increases in the 24-hour urinary excretion of N-methylhistamine (355 μg [reference value, <172 μg]) and 1-methyl-4-imidazoleacetic acid (27.3 mg [reference value, <4.5 mg]). The overall picture was consistent with TMEP with a unilateral distribution.
A Slowly Enlarging, Unilateral, Erythematous Macular Lesion—Diagnosis. Arch Dermatol. 2006;142(5):641-646. doi:10.1001/archderm.142.5.641-h