Malignant acanthosis nigricans is a rare obligate paraneoplastic dermatosis which accounts for 20% of all acanthosis nigricans cases. The clinical features of the disease are the same as in the benign forms: symmetrical, hyperpigmented, velvety papillomatous lesions mostly involving the axillae, neck, groins, periumbilical cubital and popliteal areas, mammary areolae and less often mucous membranes. However, unlike other forms, it is characterized by sudden onset and rapid spread, commonly (80%) after the age of 40, which may be a marker of malignancy and a key to early diagnosis, indicating the need for a detailed examination. It is a disorder that has no gender differences. Most cases are detected at the moment of cancer diagnosis (61.3%), in fewer cases (about 20%) prior to cancer diagnosis, and in 21% at a later stage of malignant disease. Acanthosis nigricans is usually associated with one of the three or all three forms of paraneoplastic lesions: florid cutaneous papillomatosis, acanthosis palmaris (tripe palms, pachydermatoglyphia) involving the palms and soles, as well as multiple seborrheic keratosis (sign of Leser-Trélat).
We report on a female patient with clinically established three paraneoplastic syndromes: malignant acanthosis nigricans, florid cutaneous papillomatosis, and acanthosis palmaris, which appeared before the diagnosis of advanced gastric adenocarcinoma, leading to fatal outcome.