Bizarre Parosteal Osteochondromatous Proliferation Research Articles

Bizarre parosteal osteochondromatous proliferation in the distal ulna where the lesion is continuous with the medullary cavity: a case report

BackgroundBizarre parosteal osteochondromatous proliferation (BPOP) is a rare benign bone tumor, it is also called “Nora’s lesion”. The lesion is characterized by heterotopic ossification of the normal bone cortex or parosteal bone. The etiology of BPOP is unclear and may be related to trauma. In most BPOPs, the lesion is not connected to the medullary cavity. Here we report an atypical case, characterized by reversed features compared to the typical BPOP, which demonstrated continuity of the lesion with the cavity.Case presentationAn 11-year-old female child had a slow-growing mass on her right wrist for 8 months with forearm rotation dysfunction. Plain X-rays showed an irregular calcified mass on the right distal ulna, and computed tomography (CT) showed a pedunculated mass resembling a mushroom protruding into the soft tissue at the distal ulna. The medulla of this lesion is continuous with the medulla of the ulna. A surgical resection of the lesion, together with a portion of the ulnar bone cortex below the tumor was performed, and the final pathology confirmed BPOP. After the surgery, the child’s forearm rotation function improved significantly, and there was no sign of a recurrence at 1-year follow-up.ConclusionIt is scarce for BPOP lesions to communicate with the medullary cavity. However, under-recognition of these rare cases may result in misdiagnosis or inappropriate treatment thereby increasing the risk of recurrence. Therefore, special cases where BPOP lesions are continuous with the medulla are even more important to be studied to understand better and master these lesions. Although BPOP is a benign tumor with no evidence of malignant transformation, the recurrence rate of surgical resection is high. We considered the possibility of this particular disease prior to surgery and performed a surgical resection with adequate safety margins. Regular postoperative follow-up is of utmost importance, without a doubt.

Bizarre parosteal osteochondromatous proliferation (Nora lesion) involving the spine: a case report and systematic review.

Bizarre parosteal osteochondromatous proliferation (BPOP), also termed Nora lesion, is a rare, benign tumor most often located in the hands and feet. We herein present the second reported case of BPOP affecting the spine, an uncommon location. One year after surgical excision, the patient was pain-free and showed no evidence of recurrence. We reviewed a total of 323 cases of BPOP among 101 articles, providing the first systematic update on the latest knowledge of BPOP. The age of patients with BPOP ranges from 3 months to 87 years, peaking in the second and third decades of life. The hands are the most common location of BPOP (58.39%), followed by the feet (20.81%). Imaging features play a key role in the diagnosis of BPOP, but histopathologic diagnosis remains the gold standard. Differential diagnosis of BPOP should be based on the epidemiologic and clinical features as well as clinical examination findings. Surgical resection is the most extensively used treatment for BPOP. Recurrence is common (37.44%) and can be treated with re-excision. This article can deepen our understanding of BPOP and will be helpful for the diagnosis and treatment of BPOP in clinical practice.

Bizarre parosteal osteocondromatous proliferation (BPOP) of the acromion with soft tissue recurrence.

Bizarre parosteal osteochondromatous proliferation (BPOP) is a benign but rare periosteal-originating chondrogenic tumor. It commonly arises from the hands and feet. It is slow-growing and often presents as a painless lump. On imaging, the mass is well-marginated and almost always remains contiguous with the cortical bone. Histologically, the lesion is composed of a disorganized admixture of fibrous tissue, bone, and cartilage with bizarre features. Treatment is surgical and local recurrence is common contiguous with bone. This case report demonstrates an uncommon acromial BPOP with the first reported recurrence not contiguous with the underlying cortex.

Identification of COL1A1/2 Mutations and Fusions With Noncoding RNA Genes in Bizarre Parosteal Osteochondromatous Proliferation (Nora Lesion)

Bizarre parosteal osteochondromatous proliferation (BPOP) (Nora lesion) is a benign bone surface lesion, which most commonly occurs in the digits of young patients and has a high rate of recurrence. Histologically, it is composed of a mixture of disorganized bone, cartilage, and spindle cells in variable proportions and characterized by amorphous “blue bone” mineralization. Recurrent chromosomal abnormalities, including t(1;17)(q32-42;q21-23) and inv(7)(q21.1-22q31.3-32), have been reported in BPOP. However, the exact genes involved in the rearrangements remain unknown. In this study, we analyzed 8 BPOP cases affecting the fingers, toe, ulna, radius, and fibula of 5 female and 3 male patients, aged 5 to 68 years. RNA sequencing of 5 cases identified genetic fusions between COL1A2 and LINC-PINT in 3 cases and COL1A1::MIR29B2CHG fusion in 1, both validated using fluorescence in situ hybridization and reverse transcription (RT)-PCR. The remaining fusion-negative case harbored 3 COL1A1 mutations as revealed by whole-exome sequencing and confirmed using Sanger sequencing. All these genetic alterations were predicted to cause frameshift and/or truncation of COL1A1/2. The chromosomal locations of COL1A2 (7q21.3), LINC-PINT (7q32.3), COL1A1 (17q21.33), and MIR29B2CHG (1q32.2) were consistent with the breakpoints identified in the previous cytogenetic studies. Subsequent screening of 3 BPOPs using fluorescence in situ hybridization identified 1 additional case each with COL1A1 or COL1A2 rearrangement. Our findings are consistent with reported chromosomal abnormalities and implicate the disruption of type I collagen, and perhaps of either noncoding RNA gene as a tumor suppressor, in the tumorigenesis of BPOP. The prevalence and tumorigenic mechanisms of these COL1A1/2 alterations in BPOP require further investigation.

Slučaj neobične osteohondromatozne proliferacije (Norina lezija) - kratak opis

Introduction. Nora's lesion or bizarre parosteal osteochondromatous proliferation is a rare benign bone neoplasm that is usually localized on the small bones of the hands. The paper was aimed at clinical, morphological and structural analysis of Nora's lesion case, the second registered in Ukraine. Case report. A 42-year-old male patient presented with complaints of painless swelling in the area of the distal 4th metacarpal bone and limited mobility of the ring finger. The diagnosis was based on a typical localization, combination of clinical, radiological, and histological methods; however, the right differential diagnosis was an important task in the present case, too. Conclusion. As there is still not enough data in the literature on this issue, further studies of Nora's lesion etiology will improve its understanding, thus treatment modes and prevention of recurrence, too.

Bizarre Parosteal Osteochondromatous Proliferation: A Premalignant Process?

First described by Nora et al in 1983, the bizarre parosteal osteochondromatous proliferation (BPOP) was primarily reported in the bones of the hands and feet. The lesion is often confused with other benign and malignant lesions. Rarely reported in the maxillofacial region, few cases have been reported in the literature to date. Its etiology is unknown and it has a marked propensity to recur. The objective of this presentation is to present 2 unique cases, review management philosophies, and bring attention to difficulties in accurately diagnosing this entity.

Bizarre parosteal osteochondromatous proliferation or Nora’s lesion affecting the extremities: A concise update

The bizarre parosteal osteochondromatous proliferation or Nora’s lesion is an unusual clinical entity that presents with localized swelling and pain. The characteristic radiological appearance includes a cluster of variably calcified lesions adjacent to a particular bone. However, it does not necessarily have direct continuity with its medullary region. The etiopathogenesis of this disorder is not yet fully understood. Various other lesions require careful exclusion and the use of advanced imaging modalities to supplement the diagnosis. The final diagnosis of the lesion, however, is based on the histopathological basis. However, these lesions are reported as sporadic reports or small series in the literature and are also discovered in areas other than the common locations in hands and feet. The recent research aims to throw more advanced knowledge into their causation, including genetic etiology. The symptomatic lesions may require excision for clinical relief, but recurrence is not uncommon. The future research, and preferably multi-center collaboration, is required for more insight into their comprehensive nature and clinical spectrum. A brief and crisp update of the articles published in the past 10 years describing bizarre parosteal oseochondromatous proliferation in the extremities is presented here for educational purposes for orthopedists and generalists alike.

Bizarre Parosteal Osteochondromatous Proliferation (Nora Lesion): A Narrative Review.

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.

A rare tumor at an unusual age: Pediatric bizarre parosteal osteochondromatous proliferation nora's lesion of the phalanx

<br>Bizarre parosteal osteochondromatous proliferation (BPOP) is a rare lesion that usually arises in short bones of the hand and feet. It is typically seen in the third and fourth decades, seldom seen in the pediatric age group. A 6-year-old girl was presented with swelling over the ring finger of the left hand. The radiograph showed ectopic calcification and periosteal reaction in the ring finger. Computed tomography was performed, and a BPOP diagnosis was made on the preoperative finding. Excision of the lesion with overlying pseudocapsule and decortication was performed with a piezoelectric device. The patient is currently in a routine follow-up without recurrence. There is not enough data for treatment and follow-up BPOP in pediatric patients. The present case would contribute to the literature in the management of this rare presentation.<br>

Nora’s lesion of the distal ulna: a case report

Nora’s lesion, also known as bizarre parosteal osteochondromatous proliferation (BPOP), is a very rare benign lesion with few published cases. BPOP is more common in adults during the second to third decades of life, and usually occurs on the hands and feet. Radiologically, it appears as a calcified mass attached to the bone cortex that grows rapidly and that recurs easily following resection. Aggressive features on imaging and confusing histopathological findings usually result in misdiagnosis or mistreatment. Herein, we present a case of a rare bony tumour involving the distal ulna presenting as a painless growing mass. An excisional biopsy with clear margins was performed without disturbing the ulnar nerve and arteries. There was no recurrent mass or calcified lesion 1 year after surgery. Based on its rarity and difficult diagnosis, BPOP should be considered in the differential diagnosis of a painless mass in the distal ulnar region. Careful follow-up after surgery is essential, even without lesion recurrence.

Nora’s lesion: bizarre parosteal osteochondromatous proliferation in right foot: a case report

&lt;p class="abstract"&gt;&lt;span lang="EN-US"&gt;Nora’s lesion is a benign lesion involving mainly the proximal phalanges, metatarsals or metacarpals in the hands and feet. It may be easily confused with a malignant entity and was first identified and reported by Nora et al. in 1983. We present a case of a 12 years old female with complains of a swelling over the right foot noticed 4 months ago. Plain radiograph revealed heterotrophic calcification over the dorso-lateral aspect of the head of the first metatarsal. MRI scan of the foot was suggestive of a benign pathology with a differential of bizarre parosteal osteochondromatous proliferation (BPOP) or an osteochondroma. The patient was managed with excision biopsy and lesion was excised along with the pseudo-capsule and adjoining periosteum. Cortex appeared normal and wound was washed with hydrogen peroxide and incision closed. Histopathology report was suggestive of Nora’s lesion. One year follow up of the patient showed no recurrence. BPOP proliferation is a benign lesion however differentials need to be kept in mind and treatment with excision of the lesion along with the pseudo-capsule and periosteal tissue beneath the lesion has low rates of recurrence. &lt;/span&gt;&lt;/p&gt;

Bizarre parosteal osteochondromatous proliferation (Nora’s lesion) of the talus: a case report

Introduction: Bizarre Parosteal Osteochondromatous Proliferation (BPOP), or Nora’s Lesion, is a very rare condition, with less than 200 documented cases that exist in the literature. BPOP / Nora’s Lesion of the talus has not been reported in any literature in Indonesia. Therefore, this study aim to present a unique and rare case of BPOP (Nora’s Lesion) of the talus.Case: An eighteen-year-old male patient admitted to hospital with a complaint of palpable lump at his front right ankle region since seven years ago with the size of a marble. On physical examination, there was a swelling of the anteromedial aspect of the ankle, hard in consistency, well-defined, immobile, and without neurovascular impairment. There was pain exacerbated by sports activities. There was a history of trauma at the located lump; he was fell while running on the ground a few years before the lump first arose with no fracture, wound, or swelling at that area. The range of motion (ROM) of the right ankle was less than the left ankle. The operation was performed under general anesthesia. After an incision was made, the mass was exposed and we did an osteotomy and a complete surgical excision. Conclusion: In this case, the radiographic imaging showed well-defined exostosis arising from the anteromedial aspect of the talus bone cortex, but not in continuity with it. Histopathological examination consistent with BPOP. We suggest a surgical “En-bloc” (complete surgical excision) as a recommended treatment for BPOP.

Nora’s lesion of Upper and Lower limb bones- A series of 8 cases

Introduction: Bizarre parosteal osteochondromatous proliferation (BPOP) presents as painless bony swelling and also known as Nora’s lesion. It is a benign surface osteocartilaginous lesion. This condition is seen most commonly in hands followed by feet. Long bone involvement is rare. Materials and Methods: This is a retrospective study of the patients who had visited the orthopedic OPD of our institute from January 2011 to December 2019. The diagnosis of BPOP was made by radiological evaluation and confirmed by histopathological evaluation. Results: There were 8 cases included in this study. Out of them, 4 cases (50%) were female, and 4 cases (50%) male. The age distribution of patients was 14 years to 36 years. The duration of the history of present illness was 6 months to 3 years. There were 6 cases (75%) of the upper limb and 2 cases (25%) of the lower limb. 4 cases (50%) had a history of trauma. All cases were operated on after pre-operative evaluation and the excisional biopsy specimen was sent for histopathological evaluation for confirmation. On follow up 2 cases (25%) had recurrence for which re-operation was done. Conclusion: BPOP involving long bones is exceedingly rare. The local recurrence rate after surgical resection of the lesion is high. En bloc resection of the lesion along with decortication of the underlying cortical bone was done to reduce the possibility of recurrence. Two patients in our series had a recurrence for which re-operation was done. Keywords: Nora’s lesion, BPOP, Bony swelling, Osteochondramatous proliferation.

Disruption of Jmjd3/p16Ink4a Signaling Pathway Causes Bizarre Parosteal Osteochondromatous Proliferation (BPOP)-like Lesion in Mice.

Bizarre parosteal osteochondromatous proliferation (BPOP), or Nora's lesion, is a rare benign osteochondromatous lesion. At present, the molecular etiology of BPOP remains unclear. JMJD3(KDM6B) is an H3K27me3 demethylase and counteracts polycomb-mediated transcription repression. Previously, Jmjd3 was shown to be critical for bone development and osteoarthritis. Here, we report that conditional deletion of Jmjd3 in chondrogenic cells unexpectedly resulted in BPOP-like lesion in mice. Biochemical investigations revealed that Jmjd3 inhibited BPOP-like lesion through p16Ink4a . Immunohistochemistry and RT-qPCR assays indicated JMJD3 and p16INK4A level were significantly reduced in human BPOP lesion compared with normal subjects. This was further confirmed by Jmjd3/Ink4a double-gene knockout mice experiments. Therefore, our results indicated the pathway of Jmjd3/p16Ink4a may be essential for the development of BPOP in human. © 2021 American Society for Bone and Mineral Research (ASBMR).

Quantitative bone SPECT/CT applications for cartilaginous bone neoplasms.

To evaluate the ability of quantitative values obtained with bone single photon emission computed tomography/computed tomography (SPECT/CT) to differentiate benign from malignant cartilaginous bone neoplasms. Bone SPECT/CT scans of 10 patients with 8 benign cartilaginous bone neoplasms (4 enchondromas, 1 periosteal chondroma, 1 osteochondroma, 1 bizarre parosteal osteochondromatous proliferation, 1 chondroblastoma) and 2 malignant cartilaginous bone neoplasms (1 periosteal chondrosarcoma, 1 chondrosarcoma) were retrospectively analyzed with maximum standardized uptake value (SUVmax), mean SUV (SUVmean), metabolic bone volume (MBV), and total bone uptake (TBU) of primary lesions. Mean SUVmax of 8 benign and 2 malignant cartilaginous bone neoplasms were 1.93±1.02 (range 0.59-3.41) and 6.07±0.86 (5.46-6.67), respectively with no overlap (P=0.028). Mean SUVmean of those were 1.24±0.71 (range 0.36-2.36) and 4.05±0.30 (3.84-4.26), respectively with no overlap (P=0.00036). Mean MBV of those were 7.17±4.19 (range 3.17-13.77) and 10.29±10.05 (3.19-17.4), respectively with no significant difference (P=0.74). Mean TBU of those were 9.22±8.31 (range 1.15-23.61) and 43.19±43.7 (12.26-74.13), respectively with no significant difference (P=0.47). Standardized uptake value obtained with bone SPECT/CT may be useful to differentiate benign from malignant cartilaginous bone neoplasms, thus helping the orthopedic surgeon towards the most appropriate treatment procedure.

Bizarre parosteal osteochondromatous proliferation co-occurring with a metatarsal fatigue fracture: a case report

BackgroundBizarre parosteal osteochondromatous proliferation (BPOP) is a relatively rare benign extraperiosteal osteochondroma-like proliferative lesion that shares similarities with malignant tumours in terms of morphology. The aetiology of BPOP has yet to be determined and there are no previous reports of BPOP associated with fracture.Case presentationA 57-year-old woman presented with a one-month history of pain and swelling in her right foot, which were worsened by activity and improved with rest. Physical examination revealed a hard, non-mobile mass measuring 1.5 cm × 1.5 cm on the dorsal aspect of the third metatarsal of the right foot. There was overlying erythema and tenderness on palpation. Computed tomography (CT) of the right foot demonstrated a fracture of the neck of the third metatarsal, osteolysis at the fracture site and soft tissue swelling. Bone scintigraphy revealed increased tracer uptake suggesting abnormal bone metabolism at the neck of the third metatarsal. Surgical excision of the lesion was performed. Histopathology and immunohistochemistry confirmed the diagnosis of BPOP.ConclusionBPOP is a rare benign lesion that is commonly misdiagnosed. Differential diagnosis is mainly achieved through imaging and histopathological assessment.

Multiple Nora Lesions: A Rare Case Report

Background: Bizarre parosteal osteochondromatous proliferation (BPOP), first described by Nora et al. in 1983. It is a rare lesion that occurs in the short bones of the hands and feet and eventually presents as a parosteal mass [1,2]. BPOP does not become malignant, although a high rate of recurrence following surgical resection is reported. Because of its atypical imaging findings and histopathological appearance, a BPOP might be misdiagnosed as a malignant tumor such as an osteochondroma with malignant transformation, a parosteal osteosarcoma, or a periosteal osteosarcoma [5,10]. Our case reports enlightens multiple Nora lesions in the same location, which is the first to be reported in literature to the best of our knowledge till date.

Lesion with blue bone-a case report

Bizzare parosteal osteochondromatous proliferation, or Nora‘s lesion is a unique bone lesion that most often arises in the small bones of hands and feet. It is characterised by proliferation of chondroid, bony and fibrous tissue, and is occasionally misdiagnosed as a malignant process. Our case was a 31 yr old lady, who presented with a painless swelling near the 5th metacarpal bone of right hand. X-ray showed well marginated mineralised mass arising from the cortical surface of the metacarpal bone. Histopathological examination revealed bizarre parosteal osteochondromatous proliferation composed of varying amounts of cartilage, bone and spindle cells. Cartilage was hypercellular and chondrocytes were enlarged. Ossification was irregular and had a peculiar blue tinctorial quality.

Bizarre parosteal osteochondromatous proliferation: 16 Cases with a focus on histologic variability

Bizarre parosteal osteochondromatous proliferation (BPOP) is a benign bone and cartilage forming tumor occurring on the surface of bones, predominantly on the hands and feet. A defining feature of BPOP is the purplish-blue mineralization of cartilaginous tissue, known as ‘blue bone.’ Here, we report on an institutional series of 16 cases of BPOP, including radiographic, histologic, and histomorphometric features. All tumors were composed of some element of bone, cartilage, fibrous tissue and ‘blue bone,’ though the amount of each tissue sub-type varied widely. Some cases showed focal ‘blue bone’ only, however this was a defining feature in all cases.

Bizarre parosteal osteochondromatous proliferation (Nora's lesion)

Bizarre parosteal osteochondromatous proliferation (BPOP; Nora's lesion) is the most common benign osteocartilaginous lesion. It is most commonly seen in hands followed by the long bones, feet, and skull. The clinical and pathological feature's of Nora's Lesion mimick malignant lesions. The recurrence rate of lesion is 20%–50%. We present a case of BPOP of the middle phalanx of the middle finger. The importance of the case is that involvement of hand may not rare, but it's present in the proximal phalanges is very rare. In our case, it is present in the middle phalanx of the right middle finger.