Electron microscopy of E-rosette-forming leukemic monocytes in a child with acute monocytic leukemia

✍ Scribed by Masahige Tsukada; Hiroharu Saitoh; Toshihiro Hara; Atsushi Komiyama; Taro Akabane

• Publisher: John Wiley and Sons
• Year: 1981
• Tongue: English
• Weight: 378 KB
• Volume: 47
• Category: Article
• ISSN: 0008-543X
• DOI: 10.1002/1097-0142(19810401)47:7<1800::aid-cncr2820470713>3.0.co;2-p

✦ Synopsis

A 7-year-old boy with acute monocytic leukemia (AMoL) had leukemic monocytes that formed spontaneous rosettes with sheep red blood cells (E-rosette). The E-rosette formation was observed in 75% of leukemic monocytes at 4 C and in 37% at 37 C. Cytochemical and ultrastructural studies confirmed that the rosette-forming cells were leukemic monocytes. The leukemic monocytes attached to the red blood cells at a portion of their surface and did not show any phagocytic processes at the electron microscopic level. The data from this patient seem to indicate that in a rare case of AMoL, abnormal myeloid lymphoid stem cells can differentiate to monocytes while retaining lymphoid properties.

Cancer 4731800-1103, 1981.

L I M A N MONOCYTES have Fc and C3 receptors on

H their surface, and leukemic monocytes in acute monocytic leukemia (AMoL) usually retain such receptors.'-3 However, they do not form rosettes with sheep red blood cells (SRBC), a specific marker for T-lymphocytes.

Reported here is an unusual case of childhood AMoL, in which leukemic cells formed spontaneous rosettes with SRBC (E-rosette). The E-rosette formation by leukemic monocytes has been confirmed at the electron microscopic level.

Case Report

A 7-year-old boy was admitted to Shinshu University Hospital in September 1978. At the age of 6 years, 9 months, he had visited another hospital with complaints of fever and cervical lymphadenopathy, and was diagnosed as having acute leukemia. Complete remission was attained with a combination of vincristine, 6-mercaptopurine (6-MP), and prednisolone, and was maintained with 6-MP and methotrexate.

In September 1978, he was sent to Shinshu University Hospital because of relapse of the leukemia. On admission. hemoglobin was 12.8 d m l , red blood cells 3.86 x IO'Vcu nim, platelets 20,OOO/cu mm. leukocytes 750/cu mm with a differential count of 44% lymphocytes and 56% nionocytic