Abstract

INTRODUCTION

Malignant neoplasms are one of the main causes of mortality in the world. Skeletal system involvement as metastasis is common. The primary source comes usually from breast, prostate, kidney, lung, and thyroid.[1,2] Diagnosis of these lesions often changes the treatment plan.

Primary bone tumors are rare. They account for 0.2–0.5% of all malignancies in all ages[3] and comprise 3–5% of tumors diagnosed in European children below 15 years and 7–8% in adolescents between 15 and 19 years of age.[4] Incidence of primary malignant bone tumors is about 9 in 1 million people in a year. It is slightly higher in males than females (10/million/year vs. 8/million/year).[5] It is usual for these tumors to be diagnosed late because these neoplasms are uncommon; moreover, their presentations are vague with unspecific signs and symptoms. Sometimes they are recognized and treated like osteomyelitis or simple fracture before exact diagnosis. Therefore, basic epidemiology in each region can help doctors to diagnose and manage them earlier. Also, these studies can guide researchers to find particular risk factors in that area.

According to previous researches, distribution of primary bone tumors is variable in different parts of the world. Highest rates are seen in Europe and the USA, but Asian countries have lower incidence and prevalence.[4,6,7] Although there are several epidemiologic studies of musculoskeletal tumors in the neighboring countries of Iran,[8–11] to the best of our knowledge, this report is the first documented one in Iran.

MATERIALS AND METHODS

We reviewed retrospectively charts and pathologic reports of patients who had undergone musculoskeletal open or excisional biopsies from January 1997 to December 2008. Biopsies had been taken in Chamran and Namazi Hospitals of Shiraz University of Medical Sciences, two main referral centers in the south of Iran. Pathologic slides had been reported by three expert pathologists in musculoskeletal diseases. Also, final diagnosis had been correlated with clinical presentation and radiograph findings by an orthopedic tumor surgeon (senior author). It should be mentioned that although diagnosis of several bone tumors like osteoid osteoma, osteochondroma, and nonossifying fibroma was made clinically and radiographically, open biopsies had been taken due to equivocal diagnosis. Moreover, some reports were the result of excisional biopsies (like osteochondroma and osteoid osteoma). We collected data on age, sex, anatomical site, and histopathologic type of 426 patients.

On the basis of pathologic reports, the tumors were classified as benign bone tumors, malignant bone tumors, and soft tissue tumors. The latter comprised malignant ones like rhabdomyosarcoma, fibrosarcoma, etc. Benign soft tissue tumors were excluded. There were some nonspecific sarcomas like small cell malignant sarcoma and high-grade malignant sarcoma in pathologic reports. We classified them as others in the results.

Description statistics were performed using SPSS software version 18.0 for windows (SPSS Inc., Chicago, IL, USA). Frequency and percentage of the mentioned variables were calculated.

RESULTS

Totally, 426 cases were analyzed. Male to female ratio was 1.5. There were 170 women (39.9%) and 256 men (60.1%). The oldest patient was an 84-year-old man with metastasis. There were two 4-year-old children as the youngest patients, with pathologic reports of osteofibrous dysplasia and soft tissue tumor. As shown in Table 1, 176 patients had malignant bone tumors with the peak frequency seen in patients of age between 5 and 25 years. Also, large proportion of benign bone tumors (161; 75.5%) was seen in patients younger than 25 years of age. Soft tissue tumors occurred more (10; 27.1%) in the age group of 45–54 years.

Table 1