Abstract In this article we report a case of bizarre paraosteal osteochondromatous proliferation (BPOP), also known as Nora’s lesion, arising on the distal phalanx of the fifth finger of the hand in a young-adult subject. In this paper, we discuss the possible therapeutic programme related to the grade of severity of the clinical features and underline the rarity of this lesion and the difficulty of diag- nosis, which is exclusively histological. Keywords Hand · Bizarre paraosteal osteochondromatous proliferation · Nora’s lesion Background Nora’s tumour, also known as bizarre paraosteal osteo- chondromatous proliferation (BPOP), is an exophytic pro- liferative lesion, which originates from the bony cortical surface and is characterised by a heterogeneous mixture of cartilage, bony and fibrous tissue. It represents a benign neoformation with atypical microscopical features and a tendency to relapse. In 1983 Nora described 35 cases arising in the tubular bones of the hands and feet, more frequently in the prox- imal phalanx of the hand [1]. However, in the literature, uncommon sites have been reported, such as the distal part of humerus, radius, ulna, fibula, hallux sesamoid bones, tibia and greater trochanter of femur [2–7]. The different reports, however, are always poor from a numer- ic point of view [4, 8–11], with the exception of those pre- sented by Meneses et al. [5], Abromovici and Steiner [2] and Campanacci et al. [3]. According to the different observations, the age of onset ranges between 8 and 74 years old, but the majority of patients are between 20 and 35 years old, with the same incidence in males and females. The aetiopathogenesis is still not well known, although Fechner and Mills reported the possibility of incidence in previous traumatic events [12]. In this article we report a clinical case we observed and so, starting from our experience, we focus on the clin- ical aspects, diagnostic problems and describe our thera- peutic programme. Presentation The BPOP case we describe concerns a 44-year-old man who had reported the onset of a painful, spontaneous, pal- pable swelling (about 10 years before) on the distal pha- Chir Organi Mov (2008) 92:45–49 DOI 10.1007/s12306-008-0038-3 CASE REPORT Nora’s lesion. Clinical and therapeutic considerations Biagio Moretti • Angelo Di Giovanni • Fabio Martino • Lorenzo Moretti • Silvio Patella • Vittorio Patella Received: 23 October 2005 / Accepted: 3 November 2005 / Published online: 14 March 2008 © Springer-Verlag 2008 B. Moretti · A. Di Giovanni · L. Moretti · S. Patella · V. Patella Department of Clinical Methodology and Medical-Surgical Technologies Operative Units of Orthopaedics and Traumatology University General Hospital, Bari, Italy e-mail: b.moretti@ortop2.uniba.it F. Martino O.U. of Radiology Giovanni XXIII Hospital Bari, Italy B. Moretti () Via Napoli 215 I-70123 Bari, Italy e-mail: b.moretti@ortop2.uniba.it