Parosteal Lipoma Associated with Underlying Recurrent Bizarre Parosteal Osteochondromatous Proliferation (Nora's Lesion) of the Hand / 대한정형외과학회잡지

Parosteal lipoma is a benign tumor of the mature adipose tissue that contacts the periosteum of the underlying bone directly. The tumor commonly arises in the long bones, such as the femur, radius or tibia, and often exhibits underlying osseous changes, such as a cortical hyperostosis or erosion. Parosteal lipoma arising in a finger is rare. Furthermore, there are no reports of parosteal lipoma associated with underlying bizarre parosteal osteochondromatous proliferation. The authors present a rare case of parosteal lipoma of the proximal phalanx of the little finger accompanied by recurrent bizarre paroteal osteochondromatous proliferation in a 64-year-old male patient who had previously undergone an excisional biopsy at the same location 8 years earlier.

Diagnosis and Treatment of Bizarre Parosteal Osteochondromatous Proliferation / 대한정형외과학회잡지

PURPOSE: There have been a few reports of bizarre parosteal osteochondromatous proliferation (BPOP) in Korea to date. The purpose of this study was to investigate the etiology, diagnosis, treatment, and prognosis of BPOP and to report the clinical outcomes from a single institution. MATERIALS AND METHODS: Between 1999 and 2016, six patients who were diagnosed and treated operatively at Yeungnam University Medical Center were reviewed retrospectively. The analysis was performed using medical records, simple radiographs, magnetic resonance imaging (MRI), and pathology results, based on clinical and oncological results. All patients underwent surgical treatment for complete resection. We also analyzed one patient who was initially diagnosed with BPOP, showing different clinical features during the follow-up period. RESULTS: The age of patients ranged from 17 to 60 years. All patients did not show a history of trauma. All patients showed localized edema on the tumor lesion, and three patients also showed tenderness. The tumor lesions were distributed to the femur, tibia, and humerus. All patients underwent marginal resection or wide resection. The mean follow-up period was 50.3 months. There was a malignant change in one patient, but no recurrence or metastasis. CONCLUSION: In this study, there was no difference in the incidence of BPOP in accordance with sex. Moreover, there was no significant relationship between trauma and onset of BPOP. Unlike previous reports, no recurrence occurred after complete resection. If BPOP is diagnosed, it is necessary to consider the possibility of malignant change and distinguish it from other malignant tumors.

Bizarre parosteal osteochondromatous proliferation and other similar lesions on humerus: a comparative analysis of clinicopathologic and imageologic characteristics / 临床与实验病理学杂志

Purpose To investigate the clinicopathologic and imageologic characteristics of bizarre parosteal osteochondromatous proliferation (BPOP),osteochondroma and chondrosarcoma.Methods One case of BPOP on right humerus,one case of osteochondroma on left humerus,and one case of chondrosarcoma on right humerus were analyzed and compared on their clinical,pathologic and imaging manifestations and followup.Results The patients of BPOP and osteochondroma did not feel pain,but patient with chondrosarcoma felt severe pain.Microscopically,it was composed of different amounts cartilage,bone,and spindle cells with a poorly organized distribution.It appeared bizarre chondrocyte and characterized " blue bone".The mass was arising from the surface of the bone and the lesion was not cortical erosion and continuity with medullary cavity in the imaging findings.BPOP,osteochondroma and chondrosarcoma could be distinguished by the above characteristics.Conclusion BPOP is a rare and benign osteochondroma-like lesion,which may be confused with osteochondroma and chondrosarcoma.BPOP can be diagnosed definitely by combining histology with medical imageology.

Bizarre Parosteal Osteochondromatous Proliferation in the First Metatarsal Bone: A Case Report / 대한골관절종양학회지

Bizarre parosteal osteochondromatous proliferation (Nora's lesion) is a rare benign tumor and known to be primarily occur in the small tubular bone of the hands and feet. However, it is very unusual to be reported that it occurs in metatarsal bone in Korea. Thus, we report this tumor of metatarsal bone including the literature review because we have experienced this example.

Bizarre Parosteal Osteochondromatous Proliferation (Nora's lesion) of the Big Toe. (A Report of Two Cases and Review) / 대한족부족관절학회지

Bizarre parosteal osteochondromatous proliferation (BPOP) is an rare benign tumor which involve mostly tubular bones of feet and hand. BPOP has clinical, radiographic, and histologic similarities with osteochondroma.Radiologically, BPOP has not central continuity with underlying osseous medulla. Histologically, the lesion has marked proliferative activity, and enlarged, bizzare, and binucleated chondrocytes.Despite the high risk of recurrence, treatment of choice is surgical resection. This report presents two cases of BPOP of the big toe with reviews of clinical, radiographic, and histological characteristics.

A Case of Subungual Bizarre Parosteal Osteochondromatous Proliferation of the Toe / 대한피부과학회지

Bizarre parosteal osteochondromatous proliferation (Nora's lesion) is a rare lesion with a tendency to recur. It is usually a solitary lesion that most often develops on the hands and feet. We now present a case of bizarre parosteal osteochondromatous proliferation initially misdiagnosed as subungual exostosis on the left great toe of a 13-year-old boy. The diagnosis was confirmed by radiologic and histopathologic features, followed by complete excision of the lesion. He had a relapse after two months and was treated with re-excision. We suggest that bizarre parosteal osteochondromatous proliferation should be considered in the differential diagnosis of any digital mass.

Bizarre Parosteal Osteochondromatous Proliferation of Middle Phalanx: A Case Report

Although bizarre parosteal osteochondromatous proliferation does not frequently occur, this calcified, osteal, chondromatous tumor has relatively high recurrence rates and presents clinical, radiological, histological features that can be classified with other lesions. And it is a benign disease that until now, there were no death or metastasis reports because of this tumor. This proliferation is hard to distinguish between other benign tumors and non-neoplastic lesions if it is occurred in small bone of hand or foot. We experienced bizarre parosteal osteochondromatous proliferation of middle phalanx of the little finger, and report this case and the review of relevant literature.

Aberrant Chromosomal Alterations in Bizarre Parosteal Osteochondromatous Proliferation (Nora's Lesion) of Hand: A Case Report / 대한정형외과학회잡지

Bizarre parosteal osteochondromatous proliferation is a disease similar to an osteochondroma that usually involves the metatarsal, metacarpal, proximal and middle phalanx. The symptoms are normally caused by the bone mass, the condition has a benign clinical course but recurrence is common. Recently, it was reported that there is a translocation between chromosome 1 and 17. We report a case of BPOP in the middle phalanx of hand with translocations and duplication in cytogenetic karyotyping with a review of relevant literature.

Bizarre Parosteal Osteochondromatous Proliferation: A report of five cases

Bizarre parosteal osteochondromatous proliferation was first described in 1983, when Nora and his collegues reported 35 examples of a proliferative lesion involving bones of the hands and the feet. In 1993, Meneses reported 65 cases of this condition. A fourth of all the reported cases involved the long bones. It is important to identify the clinical, roentgenographic, and histologic characteristic to seperate it from other entities because it is a benign lesion with atypical microscopic features with a tendency to recur. Roentgenograms show a calcific mass attached to the underlying cortex having a broad base. Histologically, the lesion exhibites proliferative activity, irregular bony cartilaginous interfaces, and enlarged, bizarre, and binucleated chondrocytes. We reviewed the bone tumors, diagnosed in the KyungHee University Hospital, dated from 1984 to 1994. Five cases were revised to Nora's lesion, all of which were previously diagnosed as osteochondroma. The ages of the patients ranged from 12 to 57 years (median, 19 years), and all of them were males. Two cases involved the bones of hands and feet (metacarpal and talus), and 3 cases involved the long bones (humerus, fibula, and ulna). One lesion involving the humerus has a recurrence. No metastasis had been reported.