Internal cancers such as of the lung and stomach can cause the palms to become thickened and velvety such that they look a lot like tripe, the thick velvety insides of cows, sheep and so forth that make delicious dishes - depending of course on one’s taste - tripe palms.
Tripe palms are not due to the presence of cancer cells in the palms but are the result of substances produced by cancer cells elsewhere in the body or the body’s response to cancerous products which result in the palms becoming thick and velvety.
Although tripe palms are rare, the majority of individuals with tripe palms will have an internal malignancy, thus recognizing tripe palms is important.
Paraneoplastic phenomena such as tripe palms are phenomena due to the presence of cancer cells within the body not directly caused by the local presence or effects of cancerous cells.
Patel A, Teixeiria F, Redington AE. Palmoplantar keratoderma ("tripe palms") associated with primary pulmonary adenocarcinoma. Thorax, 2005 (11):976. Go to reference