Context: Primary cutaneous lymphoma is an uncommon, extranodal lymphoma, and it is usually more indolent with a better prognosis than its histologically similar systemic counterpart is.
Objectives: To illustrate the clinicopathologic features of cutaneous lymphomas in Taiwan and to compare the relative frequencies of subtypes of cutaneous lymphoma among different geographic areas.
Design: A total of 56 patients with cutaneous lymphomas were retrospectively collected and were reclassified according to the 2005 World Health Organization and the European Organization for Research and Treatment of Cancer and the 2008 World Health Organization classifications. The data were compared with those from other studies for different geographic areas.
Results: Thirty-one (55%) tumors were primary cutaneous lymphomas, and twenty-five (45%) tumors were secondary or concurrent cutaneous lymphomas. Among primary cutaneous lymphomas, 23 cases (74%) were T-cell or natural killer-cell lymphomas, and 8 cases (26%) were B-cell lymphomas. The most common types were extranodal natural killer/T-cell lymphoma, nasal type, and primary cutaneous peripheral T-cell lymphoma, unspecified (5 cases each; 16%). In contrast with other primary cutaneous B-cell and T-cell lymphomas, either primary or secondary extranodal cutaneous natural killer/T-cell lymphomas, nasal type, had extremely poor prognoses (1-year overall survival, 0%).
Conclusions: This study showed that the frequency of subtypes of primary cutaneous lymphoma varied in different geographic areas. Compared with the Western countries, there was a higher frequency of extranodal natural killer/T-cell lymphoma, nasal type, and a lower frequency of mycosis fungoides in Taiwan. Extranodal natural killer/T-cell lymphoma, nasal type, also had an extremely poor prognosis compared with other lymphomas.