Skin appendage neoplasm Pilomatrixoma Pilomatricomas usually are asymptomatic (pain appears only with associated inflammation and ulceration); deeply seated, firm, nontender subcutaneous masses adherent to the skin but not fixed to the underlying tissue. Stretching of the skin over the tumor shows the "tent sign" with multiple facets and angles, a pathognomonic sign for pilomatricoma. In addition, pressing on one edge of the lesion causes the opposite edge to protrude from the skin like a "teeter-totter". Both these "tent sign" and "teeter-totter sign" are the most helpful clinical clues to the diagnosis of pilomatricoma. SNOMEDCT_US:44155009 Pilomatricoma is an asymptomatic slowly growing benign cutaneous tumor, differentiating towards the hair matrix of the hair follicle. It is covered by normal or hyperemic skin, and usually varies in size from 0.5 to 3 cm. SNOMEDCT_US:274901004 UMLS:C0206711