Chronic lymphocytic leukaemia masquerading as a backache

摘要

An innocuous backache may be a clue to something more serious. We present the case of a seventy two year old man with a backache ,who was diagnosed as a metastasis of chronic lymphocytic leukaemia (CLL).Metastasis of chronic lymphocytic leukemia to the bone is an extremely rare complication .We report the first case of CLL metastasis to the proximal femur. This is perhaps the second case of a metastasis of CLL to the bone . Diagnosis depends on the histology. Its presence should be considered in patients with CLL presenting with low back pain . One should be aware of its existence or it may be missed . Introduction Chronic Lymphocytic Leukemia (CLL) is the most common lymphoproliferative disease and affects the older people. It is characterised by uncontrolled proliferation and accumulation of mature B lymphocytes. In most cases, it is asymptomatic. Symptoms can occur secondary to bone marrow infiltration. The spleen, lymph nodes, liver and bone marrow are primarily involved. A second malignancy may be encountered in a patient with CLL. There are reports of spread of CLL to the leptomeninges, gastro-intestinal tract, prostrate and intervertebral disc(1,2,3,4,). CLL seldom involves the bone and may present with areas of osteopenias (2). A report of presentation of CLL as a pyogenic arthritis of the proximal interphalangeal joint exists (5). A literature search brought forth a single case of spread of CLL to the bone (6). However , there are no previous reports of metastasis of CLL to the proximal femur. Case Report We present a case of a seventy two years old gentleman, who presented to us with a low backache. Blood investigations followed by the haematologist’s opinion confirmed a CLL (Rai stage 0 ). MRI of the spine aroused a suspicion of leukemic infiltration of T9 vertebra. A spinal biopsy revealed a normal histology. A trephine biopsy from the iliac crest confirmed a CLL. A search for a primary in other organs was futile. With analgesia, the pain improved and the patient continued to walk with a stick. He was reluctant to investigate further and returned to work. Eight months later he was admitted with excruciating lower back pain restricting him to his bed. He felt better with analgesia and bed rest. Unfortunately, during his stay in the hospital, he had sudden onset of sharp pain in his right thigh. Radiograph revealed a pathological subtrochanteric fracture of his right femur with evidence of metastasis (Fig 1). The opposite femur radiograph also exhibited similar changes without a fracture(Fig 2). The subtrochanteric fracture in the right femur was fixed with a long gamma nail(Fig 3) . The opposite femur was also fixed with a long gamma nail as a prophylaxis(Fig 3). The reamings from the subtrochanteric fracture were sent for histological study.To our surprise, the histological analysis revealed a B cell chronic lymphatic leukaemia.