The Granulated Sweetener Packet Sign

The last two decades have seen a continuing shift from visual and tactile diagnoses in dermatology towards novel, state-of-the-art, and noninvasive instrumental technologies. Against the current tide toward replacing classical physical examinations with sophisticated high-tech ones, the present article will describe an easy-to-use and practical clinical sign to differentiate between metastases of malignant lesions and apparently benign inflamed/infected dermoid cysts. Epidermoid cysts (sometimes erroneously called "sebaceous cysts") are subcutaneous nodules containing keratin and encapsulated by an epidermoid wall. They are mobile nodules, smooth to the touch, variable in size, and most commonly located on the face, neck, and trunk. They may rupture or become infected and inflamed, red, painful, or purulent. Diagnosis is usually clear-cut, and uncomplicated cysts may not require treatment. Patients usually seek advice and request excision for esthetic or medical reasons (inflammation/infection). A 48-year-old otherwise healthy woman presented for a consultation because of a small cyst on her forehead (Figure 1). Two-finger palpation of the cyst revealed that it did not have the gelatinous fluctuant consistency of an ordinary cyst, but rather felt like a packet of granulated sweetener. The histological diagnosis of the cyst was small-to-medium-sized T-cell lymphoma. The diagnostic challenge of this case was to distinguish between metastases and an ordinary innocent-appearing cyst. The impression of a packet containing granular material upon palpitation of a cyst can be the definitive clue to detecting metastases of malignant lesions among what appear to be uncomplicated dermoid cysts. We have seen several such cases of subcutaneous nodules that turned out to be metastases of sarcomas and carcinomas, all of them with the same impression of a packet of granulated material upon palpation. We propose the term "granulated sweetener packet sign" for this diagnostic sign.