Differentiating primary cutaneous lymphoma from secondary cutaneous lymphoma is crucial since the former develops first in the skin without any systemic involvement. Because of the clinical and histological similarities between primary and secondary cutaneous lymphomas, distinguishing between the two can be difficult. In order to prevent any diagnostic issues, it may be necessary to do thorough staging investigations.
PCTCL is more prevalent than PCBCL since seventy-one percent of cases are PCTCL (7.7 cases/million inhabitants/year), while 29 percent of cases are PCBCL (3.1 cases/million inhabitants/year), according to an American epidemiological study published in 2009; More males than females are affected by PCL, with a male-to-female ratio of 1.72 (14.0 vs. 8.2 cases/million inhabitants/year). Also, the rate is highest among blacks, lowest among Hispanic Caucasians, and intermediate among Asians, with an annual rate of 11.5, 7.9, and 7.1 cases per million people.
Blacks had a higher incidence of PCTCL (10.0 cases/million inhabitants/year) while non-Hispanic Caucasians had a higher incidence of PCBCL (3.5 cases/million inhabitants/year).
Incidence of PCL was higher in 2001-2003 (14.3 vs. 5.0 cases/million inhabitants/year) and stabilized in 2004-2005 (12.7 vs. 5.0 cases/million inhabitants/year) according to this study.