Classification and proper treatment of extranodal lymphoma is hindered by the diversity of lymphoma types and the relative rarity of many of these tumour types. In order to review controversial issues in extranodal lymphoma diagnosis, a joint Workshop of the European Haematopathology Association (EAHP) and the Society for Hematopathology (SH) was held, where 99 selected cases were reviewed and discussed. This Workshop summary is focused on the most controversial aspect of cutaneous B-cell lymphoma, other extranodal B-cell lymphomas, plasmablastic lymphoma and anaplastic large-cell lymphoma in extranodal sites, and makes practical recommendations about diagnosis and therapeutic approaches.