Adult T-cell leukemia predominantly involving exocrine glands.

OBJECTIVES

We describe a rare case of adult T-cell leukemia (ATL) presenting with dry mouth and swelling of bilateral parotid and submandibular glands. The unusual involvement of these exocrine glands by malignant cells prompted us to conduct a detail characterization of these infiltrating and circulating leukemic T cells, which may provide insight to the pathogenesis of exocrine involvement in ATL.

METHODS

Immunophenotyping of peripheral ATL cells and microscopic examinations of various organs prepared by autopsy were performed. Analysis of the repertoire of T-cell receptor (TCR) of parotid gland-infiltrating ATL cells using molecular and immunohistochemical examinations were also performed.

RESULTS

Microscopic examinations of various organs prepared by autopsy revealed the predominant and specific exocrine gland infiltration of ATL cells. Reverse transcription-polymerase chain reaction (RT-PCR) followed by both TCR spectratyping and complementary determining region (CDR)-3 sequencing analysis of TCR Vbeta of parotid gland-infiltrating T cells revealed a relatively restricted but not single usage of TCR Vbeta. Immunohistochemical analyses of parotid gland specimens detected only a small number of TCR Valphabeta-positive cells in parotid gland-infiltrating ATL cells.

CONCLUSIONS

The predominant infiltration of ATL cells in exocrine glands implied that these T cells recognized exocrine gland-specific antigen. However, the absence of both TCR Vbeta mRNA transcripts and TCR Valphabeta protein expression in most ATL cells suggested that antigen recognition via TCR may not have played a major role in adhesion and subsequent infiltration into the exocrine glands in this patient. These results provide important background information to further elucidate the pathogenesis of exocrine gland-specific inflammation.