Accuracy of clinical diagnosis, imaging methods, and biopsy in tumours and pseudo-tumours of the hand.

Background: The appropriate use of imaging methods in bone and soft tissue tumours of the hand is well established in the radiological literature. However, since most of the tumoral conditions of the hand are benign, the use of imaging methods may be based on clinician preferences and technical availability. The aim of this work is to present the experience in our institution in the management of tumours and pseudo-tumours of the hand and to review the utility of different imaging methods in their diagnosis.

Methods: We present a retrospective and consecutive case series of patients referred to Hospital Universitario Virgen de las Nieves due to clinical suspicion of hand tumour in the last 10 years. We assessed the accuracy of clinical and imaging diagnoses, matching the final pathological or surgical results, considering a diagnosis as "correct" if it was included in the differential diagnosis suggested in the clinical (including all provided diagnoses) or radiological report (only the first 2 diagnoses), respectively. Biopsy accuracy was contrasted with surgical findings.

Results: We included 175 patients with a pathological or microbiological diagnosis of hand tumors, obtained through surgery (n=124) and/or core needle biopsy (n=62), or puncture-drainage (n=30). Among these, 21 cases were identified as infectious, metabolic, or inflammatory processes, while 154 were classified as hand tumours or pseudotumours (101 in soft tissues and 53 in bone). The overall diagnostic accuracy (95% confidence interval) for each approach was as follows: clinical diagnosis, 26.3% (19.8-32.8%); ultrasound, 72.6% (64.3-80.8%); magnetic resonance imaging (MRI), 80.6% (73.8-87.4%); computed tomography (CT), 84.6% (74.8-94.4%); and radiography, 46.8% (38.6-55.0%). The overall accuracy of imaging was 81.1% (75.3-86.9%). For soft tissue masses, the diagnostic accuracy was: clinical, 30.7% (25.5-42.1%); ultrasound, 69.8% (62.9-80.1%); MRI, 73.9% (65.5-83.4%); CT, 75.0% (30-92%); and radiography, 20.3% (14-33%), with an overall imaging accuracy of 75.2% (69.2-84.1%). For bone tumours, the accuracy was: clinical, 10.9% (5.2-21.8%); ultrasound, 75.0% (46.8-91.1%); MRI, 90.7% (78.4-96.3%); CT, 92.3% (79.7-97.3%); and radiography, 83.3% (71.3-91%), with an overall imaging accuracy of 89.1% (78.2-94.9%). Biopsy accuracy was 90.7% (83-98.5%) overall, 86.4% (74-98%) for soft tissue masses, and 100% (81.5-100%) for bone tumours.

Conclusions: Imaging outperforms clinical diagnosis in terms of accuracy and should be mandatory before any interventional procedure. Imaging-guided biopsy is an efficient complementary technique when doubts persist about the nature or potential malignancy of a hand tumour.