A transplantable mouse lymphoma with unusual azurophilic granules.

A transplantable malignant lymphoma arising spontaneously in the C3H/Jax Heston mouse line is described. Such a spontaneously arising lymphoma within this strain has not been previously reported. The tumor exhibits 100% transmission in the C3H/HeJax mouse line and has been successfully carried through 113 transfers. No spontaneous regression was observed in 678 animals. The tumor terminates in lymphocytic leukemia after 2 to 3 weeks. The neoplastic cells contain azurophilic granules which stain purple-red with Wright's or tetrachrome blood stains, are not metachromatic with toluidine blue, are not peroxidase positive and show a pleomorphic structure at the level of electron microscopy. While the nature and function of azurophilic granules remains undetermined, their presence in this transmissible tumor offers a better opportunity to study them.