Edoardo Ipponi, Elisa Ferrari, Damiano Ruinato Alfio, Silvia De Franco, Rodolfo Capanna, Lorenzo Andreani
University of Pisa: Department of Orthopedics and Trauma Surgery.
Acta Med Litu. 2022;29(2):176-193. doi: 10.15388/Amed.2022.29.2.4. Epub 2022 Jun 29.
Bizarre parosteal osteochondromatous proliferation (BPOP), or Nora lesion, is a rare proliferative disease arising from the parosteal region of bones. Although BPOP's pathogenesis is still not certain, modern literature suggests it to be a tumor-like lesion or even a benign neoplasm. Due to the extremely low incidence, to this date studies on the topic are limited to case reports and a few case series. This narrative review aims to resume literature on BPOP and provide an overview of its natural history, morphologic characteristics and prognostic horizon.
A systematic research of the literature was done to identify studies reporting on patients who suffered from BPOP between 1983 and 2021. We collected data regarding aetiologic and pathogenetic theories, patients' personal data and anamnesis, lesions' location, clinical presentation, imaging features, pathological appearance, treatment and prognosis.
We identified 322 cases of BPOP with a mean age of 34.3 years at the moment of diagnosis. There was no gender difference. The most involved site was the hand, followed by the foot. A history of trauma was reported for 14.7% of the cases. 38.7% of the patients had pain. Literature defined typical radiographic and microscopic patterns that characterize Nora lesions. While imaging is fundamental to orientate towards BPOP, histological evaluation is mandatory to get the definitive diagnosis. To this date, only reliable therapeutic option is represented by surgical resection. BPOP is burdened by a risk of recurrence that accounts to 37.4%.
BPOP is a rare benign disease that should be considered during the differential diagnosis of parosteal lesions, especially in the acral regions. Careful diagnostic evaluations are necessary to get the correct diagnosis and wide margins of resection are recommended to minimize the relatively high risk of local recurrence.
奇异型骨旁骨软骨瘤样增生（BPOP），即诺拉病变，是一种起源于骨旁区域的罕见增殖性疾病。尽管BPOP的发病机制尚不确定，但现代文献表明它是一种肿瘤样病变，甚至是良性肿瘤。由于发病率极低，迄今为止关于该主题的研究仅限于病例报告和少数病例系列。本叙述性综述旨在总结有关BPOP的文献，并概述其自然史、形态学特征和预后情况。
对文献进行系统检索，以确定1983年至2021年间报道BPOP患者的研究。我们收集了有关病因和发病机制理论、患者个人资料和既往史、病变部位、临床表现、影像学特征、病理表现、治疗和预后的数据。
我们共识别出322例BPOP病例，诊断时的平均年龄为34.3岁。无性别差异。最常累及的部位是手，其次是足。14.7%的病例有外伤史。38.7%的患者有疼痛症状。文献定义了诺拉病变的典型影像学和微观模式。虽然影像学对于BPOP的诊断至关重要，但组织学评估是确诊的必要条件。迄今为止，唯一可靠的治疗选择是手术切除。BPOP的复发风险为37.4%。
BPOP是一种罕见的良性疾病，在骨旁病变的鉴别诊断中应予以考虑，尤其是在手足部位。需要进行仔细的诊断评估以获得正确诊断，建议广泛切除边缘以将相对较高的局部复发风险降至最低。
