Primary non-Hodgkin's lymphoma of the transverse colon presenting as dermatomyositis: case presentation and literature review.

Primary extranodal non-Hodgkin's lymphoma of the transverse colon is a rare presentation of non-Hodgkin's lymphoma or colonic neoplasm. Dermatomyositis is an autoimmune condition of the skin, muscle, and blood vessels that when associated with malignancy is a true paraneoplastic syndrome but is rarely associated with non-Hodgkin's lymphoma. We present a case of primary non-Hodgkin's lymphoma of the transverse colon diagnosed after the presentation of dermatomyositis and review the literature on dermatomyositis and hematologic neoplasm.