En este artículo los autores presentan el caso de un hombre de 19 años de edad portador de beta talasemia mayor que fue referido para cintigrafía ósea con Tc99m metilendifosfonato (Tc99m MDP) por un cuadro de lumbalgia. Este caso muestra muchas de las repercusiones de la beta talasemia mayor en el esqueleto. Además, podemos observar signos indirectos de algunas endocrinopatías asociadas.

ABSTRACT:

In this article, the authors describe a 19 year old man with beta-thalassemia major and back pain, who was studied with a Tc99m Metilendiphosphonate (Tc99m MDP) bone scan. This case shows many of the complications of beta-thalassemia major in the skeletal system. Also we can see some indirect signs of endocrinopathies associated.

Key words: Beta-thalassemia major, Insufficiency fractures, Osteopenia, Growth retardation, Bone deformities.

Beta-thalassemia major is also known as Cooley’s disease. The clinic onset is near 6^th month of life with severe anemia and spleen and hepatic enlargement. The patients have loss of bone mass, fractures, and endocrinopathies as complications of the transfusional treatment and marked facial bone deformities as a characteristic feature of the syndrome (1). We report the interesting findings in a bone scan of a patient with beta-thalassemia major, and explain the physiopathologic basis of these signs.

MATERIAL

CASE REPORT

A 19 year old man with beta-thalassemia major diagnosed at infancy had been treated with transfusions since 10 to 12 years, and then with esplenectomy. He had hipogonadism and hipothyroidism diagnosed at 15 year. He also had osteoporosis and was treated with calcium and calcitonin for two years. In the last year he had three inssuficiency fractures (left radium, femur and astragalo).

Because of severe low back pain of one month, he was sent to our service for a bone scan.

Two hours after the injection of 24 mCi (888 MBq) of Tc-99m MDP we acquired anterior and posterior whole body scans with 1.500.000 counts each one and 500.000 counts lumbar spine and skull planar images.

Whole body scans showed generalized increased tracer uptake, with increased skeleton-to-soft tissue ratio (Fig 1).

There were focal spots of major activity at both frontal bones (Figs 1, 2), lumbar spine at L2, L4 and L5 (Figs 1, 3), rib cage at 5 ^th, 9 ^th and 11^th posterior left ribs (Figs 1, 3), right femoral head and left femoral distal diaphysis (Fig 1). All of them suggested osteoporotic insufficiency fractures .

Cranial bones showed some of the classical deformities of the thalassemia: prominent frontal and maxilar bones and thickening of the diploe (Figs 1, 2).

There was increased uptake in metaphyses of large bones considering the patient´s age, suggesting growth retardation (Fig 1).

Figure 1(click=zoom)

Figure 2(click=zoom)

Figure 3(click=zoom)

Cooley’s original description of beta thalassemia major included marked bone deformities as a characteristic feature of this syndrome (1, 2). The patients typically have pronounced vertical diploe and mandibular growth direction, prominent mandibular incisors, frontal bones enlarged and narrowed nasal cavity (1, 3). These are due to expansion of haemopoiesis sites attempting to compensate for the congenital anaemia, and are prevented by blood transfusions from infancy. In this patient the transfusions started at 10 years of age, so he was anemic for a long time and probably he had expanded haemopoiesis.

Regular blood transfusions lead to secondary hemochromatosis. As a consecuence of chronic iron overload, many endocrinopathies may occur (1, 2). The most frequent endocrine dysfunction is hypogonadotropic hypogonadism, which is mainly responsible for osteopenia (4). Hypothyroidism also can occur as a complication of transfusional therapy and iron overload.

This patient had both diseases, and had secundary osteoporosis. The generalized increased tracer uptake, with increased skeleton-to-soft tissue ratio and the findings suggesting osteoporotic insufficiency fractures probably were due to osteoporosis.

In transfusion dependent thalassemic patients abnormal growth and delayed puberty are frequent findings (5). Although delay in onset of puberty is a common cause of growth failure in adolescent thalassemic patients, growth retardation could also be due to iron overload, the toxic effects of desferrioxiamine, or the development of other endocrinopathies such as growth hormone insufficiency or primary hypothyroidism (6).

The bone scan in this case showed many signs of the classical bone diseases reported in severe beta-thalassemia major.