Skeletal Radiol (2004) 33:234–236 DOI 10.1007/s00256-003-0710-5
Yener Saglık Tuba Karagülle Kendi H. Yusuf Yıldız Aziz Erakar Adem Güngör Selim Erekul
Received: 12 March 2003 Revised: 19 September 2003 Accepted: 23 September 2003 Published online: 13 November 2003 © ISS 2003 Y. Saglık · H. Y. Yıldız · A. Erakar Department of Orthopaedic Surgery, Ankara University School of Medicine, 06100 Ankara, Turkey T. K. Kendi Integra MR Imaging Center, Tahran Cad. No: 38/11 Kavaklıdere, Ankara, Turkey T. K. Kendi (✉) CMRR, University of Minnesota, 2021 6th Street SE, Minneapolis, MN 55455, USA e-mail:
[email protected] Tel.: +1-612-6262001 Fax: +1-612-6262004
C A S E R E P O RT
Clavicular osteoma associated with bronchial osteomas
A. Güngör Department of Chest Surgery, Ankara University School of Medicine, 06100 Ankara, Turkey
Keywords Osteoma, clavicle · Bronchi · Radiographs · CT
S. Erekul Department of Pathology, Ankara University School of Medicine, 06100 Ankara, Turkey
Abstract Osteoma is a rare benign tumor, composed of bony tissues. It predominantly involves the skull but rarely the long bones. In this report we present a case of clavicular osteoma associated with bronchial osteomas. This association has not previously been reported. There was no evidence of Gardner’s syndrome.
Introduction Osteoma is a benign, relatively rare, usually solitary lesion composed of either compact bone with Haversian systems or ordinary trabecular bone with marrow. It usually arises in the skull and extremely rarely in the long bones [1, 2, 3, 4]. Clavicular involvement of osteoma is extremely rare but is not unique [4]. Osteoma in sites other than the cranial bones is a rare event except in Gardner’s syndrome. In this report we present an osteoma involving the left clavicle and multiple osteomas of bronchi. Colonoscopy revealed no polyps.
Case report A 27-year-old man presented with a 4–5 month history of a painless mass in the area of his left clavicle. There was no history of
trauma and family history was negative for Gardner’s syndrome. Physical examination revealed a 3×2 cm non-tender hard mass in the left clavicle without any limitation of movement. Laboratory studies were within normal limits. Stigmata of Gardner’s syndrome were not observed. Radiographs of the left shoulder revealed a 8×6 cm, mushroom-shaped blastic mass in the proximal and mid-portion of the left clavicle (Fig. 1). Computed tomography demonstrated a dense lesion with sharply outlined margins and no associated soft tissue mass. Bone scintigraphy showed accumulation of the tracer in the mid-portion of the left clavicle but not in the chest. Computed tomography of the thorax demonstrated multiple peribronchial well-defined calcified nodules extending along the left lower lobe bronchus (Fig. 2). Surgical total excision of the clavicle with left pneumonectomy was performed on the presumption of an osteosarcoma with metastases. Pathological examination of specimens from both clavicle and bronchi showed compact cortical bone consistent with osteoma (Fig. 3). Colonoscopy was performed to search for polyps but no abnormality was found. The patient had an uneventful follow-up period. At 6 months postoperatively he is symptom-free, except for some limitation of movement.
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Fig. 1 Radiograph of the left shoulder reveals a 8×6 cm, welldefined blastic mass in the proximal and mid-portion of the left clavicle
Fig. 3 Specimens from the clavicle (A) and lung (B) reveal compact bone consistent with osteoma
Fig. 2 Computed tomography of the thorax demonstrates multiple peribronchial well-defined calcified nodules extending along the left lower lobe bronchus
Discussion Osteomas are benign bone-forming tumors that usually arise in the skull and rarely in the long bones [1, 2, 3, 4]. Lesions are usually located in the inner and outer tables of the calvarium, the mandible, and the facial bones. Lesions in the long bones may be multiple and often associated with Gardner’s syndrome, which is characterized by familial polyposis coli leading to carcinoma, multiple osteomas and skin/soft tissue tumors [1, 5]. Although the clavicle is the only long bone to be ossified intramembranously like skull bones, it is an extremely unusual site for osteoma [2, 6].
The radiological appearance of osteoma is usually that of a round or ovoid, sharply marginated blastic mass with no associated soft tissue mass. The skull lesions are usually dome-shaped and arise from periosteum and juxtacortical tissues [1]. Osteomas of long bones seem to arise intramembranously but may also be periosteal or juxtacortical in origin [1, 2, 3, 4]. Malignant transformation of this lesion has not been reported and recurrence of the lesion following excision is reported as an infrequent event [7]. Novak et al. [8] suggested that osteomas with mechanical complications may show increased radio-tracer accumulation on bone scans and osteomas with “cold” bone scans can be accepted as relatively inert. They suggested surgical excision of osteomas with increased activity and follow-up of those which are “cold”. Lambiase et al. [3] observed a degree of radionuclide uptake in their series of patients and felt it was probably secondary to the summation effect, caused by the added thickness of cortex at the site. However, the degree and intensity of uptake did not approach that of osteosarcoma. In our case there was also slight accumulation of radionuclide at the left clavicle; however, there was no radionuclide uptake in the chest.
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Microscopically, osteomas are composed of either compact bone with Haversian systems (compact osteoma), as in our case, or ordinary trabecular bone with marrow (spongy osteoma). The stroma should not contain osteoid and osteoblastic cells, suggestive of osteosarcoma. Parosteal osteosarcoma, a low-grade anaplasia, can be mistaken for a benign lesion; in fact in the past it was named as parosteal osteoma. Parosteal osteosarcomas are usually more than 5 cm in diameter with a “pasted on” radiological appearance. They usually have peripheral or central foci of cartilage production undergoing enchondral ossification, a thin collar of spindle cells about the peripheral borders of the mass on pathological examination. Recurrence might be observed within 2–15 years after the first diagnosis. In our case, the huge size of the clavicular lesion with bronchial nodular lesions resembling calcified metastases erroneously suggested to us a diagnosis of parosteal osteosar-
coma with calcified lung metastases. We were, however, in error in not performing a biopsy prior to radical treatment and parosteal osteosarcoma should not metastasize unless it has de-differentiated. Osteomas involving the bronchial system have never been reported in the English literature, hence we were not suspicious of osteoma in the preoperative evaluation but rather we considered osteosarcoma with lung metastasis. Pathological examination revealed compact bone from both specimens consistent with the diagnosis of osteoma. We further investigated the patient for features of Gardner’s syndrome, but neither colonoscopy nor physical examination revealed any abnormality to support this diagnosis. Finally, we concluded that clavicular osteoma with bronchial osteomas appears to be a previously unreported combination of findings which may be clarified by future reports.
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