Chloroma. Report of a patient with unusual rib lesions.

Abstract

Chloroma is a manifestation of myelogenous leukemia in which leukemic tumors are colored green. The original description by King (10) in 1853 led to the belief that chloroma represented a separate disease entity. In 1937, however, Kandel (9) reviewed 58 cases reported in the literature and found that the chloroma without exception had been associated with myelogenous leukemia. The green color is attributed to reduced breakdown products of hemoglobin (8). In 1966 Filip and Bednář (3) showed in a series of 24 patients marked erythrophagocytosis by tumor cells. Chloroma occurs mainly in children, with predilection for the long bones, calvarium, and periorbital tissues. Roentgenographic descriptions are few, but periosteal elevation was prominent in the patients reported (1, 12). In the original roentgenographic description Gould and LeWald (5) noted underlying new bone at right angles to the shaft. No reports include roentgenographic reproductions of rib chloromas, although isolated rib lesions have been described (11). The present case report is prompted by an unusual roentgenographic appearance resembling the rachitic rosary, with symmetric involvement of the ribs anteriorly by multiple chloromas. Case Report A 10-month-old Caucasian female was admitted with the diagnosis of acute myelogenous leukemia. The child was normal at birth and well until the age of eight months when mild pallor appeared. Three weeks before admission she became anorectic and febrile with rapid respirations. The white blood cell count was 288,000, and many myelocytic blast forms were present. Hemoglobin was 6.4 g per 100 ml. Examination of bone marrow showed diffusely infiltrating acute promyelocytic cells. Treatment with 6-mercaptopurine had been instituted at another hospital. The patient did not improve, and she was transferred to the University of California Medical Center at San Francisco for further therapy. There was no family history of hematologic disease. A maternal grandmother had died of carcinoma of the uterus. Examination revealed an acutely ill female infant in severe respiratory distress. The conjunctivae were pale and the eyes were moderately proptotic. Shotty anterior and posterior cervical lymph nodes were palpable. Intercostal retractions and occasional rhonchi were noted in the chest; no rib masses could be palpated. The liver and spleen were moderately enlarged. The skin contained numerous ecchymoses. Laboratory Data: White blood cell count was 145,000; platelets, 1,000, hematocrit, 21 mm. Aspiration of bone marrow five days after onset of therapy revealed a pronounced hypocellularity with immature blast cells and erythrophagocytosis. Roentgenograms of the chest showed bilateral bulbous expansion of the anterior ends of the second through seventh ribs with periosteal elevation (Fig. 1). Patchy infiltrates were scattered throughout the lungs. Transverse radiolucent bands were seen in the proximal humeral metaphyses.