Mixed connective tissue disease associated with lupus lymphadenitis.

We have encountered 2 patients with mixed connective tissue disease (MCTD) associated with lymphadenopathy at the outset. Biopsy specimens of enlarged lymph nodes showed massive necrotizing lesions with follicular hyperplasia, which are occasionally observed in the involved lymph nodes of patients with systemic lupus erythematosus (SLE) and called lupus lymphadenitis. Usually, the only histologic finding of an involved lymph node in MCTD is lymphoid hyperplasia. These are the 2nd and 3rd cases of MCTD associated with lupus lymphadenitis. Our cases suggest that histologic studies of the swollen lymph nodes are not helpful in distinguishing MCTD from SLE.