Posttraumatic extraskeletal chondroma of the posterior neck: A systematic literature review on a rare finding and report of a case

Extraskeletal chondromas (EC) are uncommon, benign cartilaginous tumours. Most common locations are upper and lower extremities. Location in the neck is extremely rare and reported only within the anterior compartment. Data are limited to just four case reports in the paediatric population. The first case of EC in neck's posterior compartment is described herein. EC present peculiar features on imaging. Aetiology is unclear; however, trauma has been suggested as possible causative mechanism. Treatment of choice is surgical excision; recurrence is not uncommon, but additional removal seems to be resolutive. All cases in literature were asymptomatic, except for one presenting respiratory stridor. The present patient suffered from neck functional limitation and upper limb hypoesthesia. Symptoms improved after surgery in both cases. Imaging follow-up at 6 months in the present case showed no sign of recurrence. ECs are rare, benign lesions. However, they may be preoperatively misinterpreted as more malignant counterparts (both radiologically or histologically), so accurate diagnostic work-up and planning of the surgical procedure are essential

Pre-targeted immunodetection in glioma patients: tumour localization and single-photon emission tomography imaging of [99mTc]PnAO-biotin

The imaging of cerebral gliomas with radiolabelled monoclonal antibodies (MoAbs) has been previously reported. However, previous studies have been hampered by the drawback of a low tumour to non-tumour ratio. In order to overcome this problem we have developed a three-step pre-targeting method using the avidin-biotin system. The rationale of this technique consists in vivo labelling of biotinylated MoAbs targeted onto tumour deposits, when most of the unbound antibodies have been cleared from the bloodstream as avidin-bound complexes. The anti-tenascin MoAb BC2, specific for the majority of gliomas, was biotinylated and 1 mg was administered i.v. in 20 patients with histologically documented cerebral lesions. After 24-36 h, 5 mg avidin was injected i.v. followed 24 h later by a third i.v. injection of 0.2 mg PnAO-biotin labelled with 15-20 mCi technetium-99m. No evidence of toxicity was observed. Whole-body biodistribution was measured at 20 min, 3 h and 5 h post-injection. [99mTc]PnAO-biotin had a fast blood clearance and was primarily excreted through the biliary system. A dedicated single-photon emission tomography system was used to acquire brain tomographic images 1-2 h after the administration of [99mTc]PnAO-biotin. Tumours were detected in 15/18 glioma patients with a tumour to non-tumour ratio of up 14:1. This three-step method, based on the sequential administration of anti-tenascin MoAb BC2, avidin and [99mTc]PnAO-biotin, can support computed tomography or magnetic resonance imaging for the diagnosis and follow-up of patients with glioma. Further studies are required to evaluate the potential of this technique for therapeutic application