Ribosome-lamella complex in hairy cell leukemia. Ultrastructure and distribution.

Of 19 patients with hairy cell leukemia, an unusual lymphoproliferative disease, nine were found by transmission electrom microscopy to have a cytoplasmic inclusion known as the ribosome-lamellae complex (RLC). The RLC appears to be a cylinder 2.2 to 4.1 micron. in length. The internal diameter appears to be relatively constant at 0.42 micron. The outer diameter, which depends on the number of lamellae as well as on the contents of the intralamellar space, ranges from 0.52 micron to 1.27 micron. The RLC can be comprised of a single lamellae spiraled around the central core, but also RLCs with both two and three lamellae can be defined. The lamellae are composed of double tubule structures 125 A in width set in parallel arrays 125 A apart. A second array of parrallel tubules intersect at a 60 degree-angle creating a lattice. THe distance between the spiraled lamellae is dependent upon the presence or absence of ribosome-like particles. When these particles are present, the distance is usually 406 A, but when they are absent the distance is 172 A. Although experiments with certain fixatives suggest the lamellae may be primarily composed of protein rather than lipid, the exact nature of the RLC and its importance to the leukemic process remain to be determined.