Abstract: Objective To study the expression of BCL10 and associated chromosomal aberration in primary cutaneous marginal zone B-cell lymphoma （PCMZL）. Methods Tissue specimens were collected from 17 patients with PCMZL. Immunohistochemistry was used to detect the expression of BCL10. Fluorescence in situ hybridization （FISH） was performed to examine the presence of API2-MALT1 fusion gene and chromosomal aberration in BCL10, MALT1 as well as IgH genes in these cases. Results Of these patients, 94.1% （16/17） expressed BCL10 protein. The cytoplasmic expression of BCL10 was observed in 64.7%（11/17） of the patients, and nuclear expression in 29.4% （5/17）. As shown by FISH test, neither API2- MALT1 fusion gene nor chromosomal aberration in BCL10, MALT1 or IgH genes was present in these patients. Conclusions Compared with MALT lymphomas originating from tissues other than skin, PCMZL is uncommonly associated with chromosomal abnormalities; it is possible that there are unknown factors contributing to its tumorigenesis. Nuclear BCL10 is unrelated to the presence of chromosomal aberration in BCL10, MALT1 or IgH genes. Further follow-up is required to clarify the association between nuclear BCL10 and poor prognosis of PCMZL.