Acanthosis nigricans as a paraneoplastic syndrome. Case reports and review of literature.

Acanthosis nigricans (AN) is a skin disorder characterized by focal or diffuse hyperkeratosis symmetric hyperpigmentation of the skin and oral cavity mucosa. Various neoplasms, especially gastrointestinal adenocarcinomas are associated with acanthosis nigricans (AN malignant). Chemotherapy may cause regression of skin lesions.

[Primary lymphoma of the thyroid--diagnostic and treatment problems. The case report].

The authors present the case of primary malignant thyroid lymphoma and problems with distinguishing between Hashimoto's thyroiditis and primary thyroid lymphoma. Primary malignant thyroid lymphoma (PMTL) is a rare disease and difficult to diagnose. The appearance of PMTL may be preceded by Hashimoto's thyroiditis.