Occipital Condyle Osteoid Osteoma with Severe Occipital Pain that Disappeared after Surgical Resection

Abstract

osteoma is presumed to be associated with prostaglandin E2 secretion. While some articles have reported elevation of prostaglandin E2 locally, 5,6) none have reported elevated plasma concentration of prostaglandin E2 in peripheral blood. The present report is the first to describe a change of the plasma prostaglandin E2 concentration in patients with osteoid osteoma. Case Presentation I. History and examinationA 25-year-old man visited the Department of Orthopedic Surgery in our hospital with a history of severe occipital pain that worsened at night. The patient had received nonsteroidal anti-inflammatory drugs (NSAIDs) and nerve block in other institutions for pain over the previous 2 years, but the pain gradually worsened and interfered with his sleep. Computed tomography (CT) scans revealed a 10-mm radiolucency in the left occipital condyle (Fig. 1a, b). Bone scintigraphy showed localized uptake of Technetium 99m ( 99m Tc) in the same lesion (Fig. 1e). The lesion was hypointense in T 1 and T 2 weighted images in magnetic resonance image (MRI) (Fig. 1c, d). After another year of conservative treatment at our hospital without improvement, the patient decided to undergo surgical resection. The preoperative concentration of plasma prostaglandin E2 was 12 pg/mL, somewhat above the normal range (< 8.4 pg/mL). II. OperationThe patient was placed in the prone position. A curved linear skin incision was made from the right asterion to behind of the tip of mastoid process, and then curved medially inside the hairline. The vertebral artery and C1 lateral mass were identified in the suboccipital triangle. The C0/C1 facet was exposed by dissecting the obliquus capitis superior muscle and rectus capitis posterior major muscle from the occipital bone. The medial half of the occipital condyle was drilled with the help of CT navigation. The lesion could not be clearly distinguished from the surrounding bone tissue (Fig. 2). III. Pathological findingsMicroscopic examination revealed trabeculae of woven bone and surrounding fibrovascular stroma (Fig. 3a). Those findings were consistent with a diagnosis of osteoid osteoma, but no osteoblasts were detectable in the small specimen Osteoid osteoma is a benign bone tumor characterized by local pain that typically increases at night. The tumor commonly occurs in the long bones of the lower extremities, and in rare instances in cranial bones. Here we report the case of a 25-year-old man diagnosed with an osteoid osteoma of the right occipital condyle. The patient suffered from severe occipital pain in the 3 years leading up to surgery, and the pain disappeared after surgical resection of the tumor. Due caution must be taken to avoid vertebral artery injury in the surgical approach in this region. An intraoperative navigation guidance system and preoperative analysis using threedimensional reconstructed computed tomography (CT) images improved the accuracy and safety of the resection. The typical pain in osteoid osteoma is presumed to be associated with prostaglandin E2 secretion. Pla...

Huge Osteoma on Suboccipital Region: A Case Report

“…Osteoma is a benign tumor that mostly occurs in the craniofacial bone, within the frontal sinus, ethmoid, maxillary and sphenoid sinus. It is frequently found in adults during the first 3 decades of their lives and it is mainly prevalent in women 7)…”