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An Osteoid Osteoma As an Undiagnosed Cause of Three Years of Severe Pain

1997; Lippincott Williams & Wilkins; Volume: 85; Issue: 6 Linguagem: Inglês

10.1213/00000539-199712000-00029

1526-7598

Thomas Hartmann, Carsten Preis, A Gabriel, Thomas Rath, Wilfried Ilias,

Musculoskeletal synovial abnormalities and treatments

Osteoid osteoma is a benign, bone-forming tumor representing approximately 12% of all benign bone neoplasias in young individuals [1]. First described by Jaffe [2] in 1935, it has a predilection for the lower extremity, with 50% or more of lesions occurring in the femur and tibia. Of the remaining lesions, approximately 30% are equally distributed among the spine, hand, and foot [3]. There are different types of osteoid osteomas, each with differing degrees of associated osteosclerosis [4]. Pain is the leading and, in its early stages, often the only symptom of the disease and is typically described as mild and intermittent at first, later becoming more constant, more severe, and worse at night. Intense pain may be present even before the lesion is radiologically apparent. Male patients are more often affected than female patients by a ratio of 2:1, and the tumor is rare in the African-American population [5]. Trauma has been considered a contributing factor [6]. There are no pathognomonic signs or symptoms that unerringly lead to the correct diagnosis. Patients may undergo multiple procedures for the treatment of pain and/or unnecessary surgical procedures, leading to a reduced of quality of life, as in the case we present. Although there are many reports of this tumor in the surgical literature, they leave the question of pain and its treatment aside [7-9]. Case Report After manually lifting heavy items, a 44-yr-old man developed pain and paresthesias in the proximal phalanx of the fifth digit, with a pain level of 5-7 of 10 on the visual analog scale (VAS). The finger was slightly thickened, without signs of inflammation; however, it was extremely sensitive to external pressure and active or passive motion. The pain was thought to be from neuronal compression because neither radiographs nor computerized tomography (CT) revealed morphological pathology of the bony structures. Therapy with nonsteroidal analgesics was started, followed by local infiltration with anesthetics and cryotherapy. As none of these treatments resulted in pain relief, surgical neurolysis of the digital nerve was performed 4 mo after the initial trauma. Intraoperatively, the tissue around the nerves appeared to be thickened and was removed. Neither the proximal phalanx nor the proximal interphalangeal joint appeared to be affected. No new information was obtained from another radiograph and CT postoperatively. However, a radionuclide bone scan indicated that an inflammatory process might be present. Meanwhile, the patient was suspected of overreacting to his pain and was subsequently referred for psychopharmacological drug therapy. This treatment had no effect on the pain level. By this point, the patient had stopped working and had repeatedly contacted various emergency health facilities in his community to get pain relief. On physical examination, the patient localized the pain exactly and described it as burning and sticking in nature, causing him to be unable to sleep most of the night. Local anesthetic infiltration, although beneficial at first, became ineffective. Pharmacological pain management included nonsteroidal drugs and opioids, as well as tricyclic antidepressants, and was reinforced by physical therapy and psychological guidance. Magnetic resonance imaging (MRI) revealed some swelling of the tendinous sheaths and was followed by another surgical neurolysis of the digital nerve. The diagnosis of tendinous synovitis was confirmed by macroscopic examination, as well as by inflammatory reaction in the histologic specimen. Because the clinical picture indicated the presence of a complex regional pain syndrome, the patient was treated with repeated stellate ganglion blocks, followed by intravenous regional anesthesia with guanethidine to block peripheral sympathetic efferents. Blockade of the sensory afferents in the brachial plexus was accomplished by using a continuous axillary catheter. These measures reduced pain to a score of 3 on the VAS, but for only a limited time. Multiple additional surgical interventions were subsequently performed for removal of chronically inflamed tissue or neuronal decompression. Nearly 3 yr after the patient first presented with the digital pain, an endoscopic thoracic sympathectomy was performed to repeat the beneficial effect of the sympathetic blocks. The pain recurred postoperatively after 3 days with the same intensity as he had originally experienced (VAS score 5-7). The patient reacted with desperation and was becoming suicidal, demanding amputation of the painful digit. At this point, another radiograph for the first time revealed a hypodense oval area in the distal portion of the basal phalanx, measuring 8 x 5 mm and surrounded by a hyperdense border, indicating osteolytic destruction of the bone. Surgical removal of the destroyed bone mass followed. Examination of the histologic specimen revealed the presence of an osteoid osteoma. After this operation, the patient was immediately free from pain. One year later the patient is still pain free and fully reintegrated into the workplace. Discussion The radiographic hallmark of osteoid osteoma is the central nidus, a 2- to 10-mm focus of osteoid nested in a more radiolucent fibrous stroma, surrounded by marginal sclerosis. Current treatment is excision of the nidus, although other treatments, such as percutaneous tomography-guided thermocoagulation, have been described [2]. Several hypotheses have been proposed to explain the intensity of the pain. It was originally suggested that nerve endings might be stimulated by the high pressure because of the increased blood flow within the tumor [11]. There are also nerve fibers identified in the fibrous zone around the nidus, which are presumed to be components of the autonomic nervous system [12]. This could explain the pain reduction after sympathetic blocks in our patient. The pain in our patient was also reduced to some extent by non-steroidal antiinflammatory drugs, which suggests some contribution of prostaglandins to pain development in this tumor. Prostaglandins may directly stimulate free nerve endings inside or close to the tumor by lowering the nociceptive threshold [13,14]. Other diagnostic entities that may be manifested as extremity pain related or unrelated to trauma include tumors (either primary or metastatic), infectious or aseptic inflammatory processes of the bone and/or neighboring structures, and all the pathologies of regional somatosensoric and sympathetic nerve structures, or arthrotic alterations of the joints. Plain radiographs do not provide a clear diagnosis of osteoid osteoma [15]. Because of the prominent marginal sclerosis of osteoid osteomas, CT is more sensitive [16]. Nevertheless, false-negative results have been reported [9], as illustrated by our case. It is thus far from clear what role MRI might may play in diagnosis [17,18]. MRI remains a less informative method when osteoid osteoma is suspected [8]. Although diagnosis can almost always be made with radionuclide bone scan [19], the scan performed early in our case showed only signs of an inflammatory process retrospectively confirmed by our radiologists two years later. Persistent bone pain accompanied by nonspecific radiographic as well as scintigraphic findings should make one suspicious of osteoid osteoma [3]. This suspicion should encourage more persistent efforts to reach a diagnosis and could thus help to reduce ineffective, unspecific measures widely used to treat pain. The authors thank Prof. Robert Sladen and Prof. Dan Sessler for their critical review of the manuscript.