Original ContributionFibrosseous pseudotumor of the digit: a clinicopathologic study of 43 new cases
Introduction
Fibroosseous pseudotumor of the digits (FOPD) was first described by Dupree and Enzinger [1] in 1986 as a benign subcutaneous fibroblastic and osseous lesion, predominantly without zonation. They noted the following features: focal hypercellularity, cellular atypia, and increased mitotic activity that may lead to a mistaken pathologic diagnosis of sarcoma, resulting in an unnecessary amputation of the digit. Two other older series discussed this rare entity [2], [3]. We reviewed new FOPD cases from the Armed Forces Institute of Pathology (AFIP), since the time it was first described, and observed the features of FOPD to establish its relationship with myositis ossificans (MO) and to differentiate it from other distal extremity fibroosseous lesions.
Section snippets
Materials and methods
Fifty-two cases coded as FOPD or MO limited to the hands and feet were retrieved from the AFIP Soft Tissue Pathology Registry. These were consult cases from 1980 to the present—that is, cases that came to the AFIP after the cutoff date for the original publication of this entity. Cases with incomplete data or those better diagnosed as other conditions (eg, bizarre parosteal osteochondromatous proliferation [BPOP]) were excluded. Slides, available radiologic images, immunohistochemical stains,
Results
Forty-three FOPD cases were included in the study, comprising 17 (40%) male and 26 (60%) female subjects. Patient age ranged from 10 to 64 years of age, with a mean and median of 40 years. Tumor locations were equally distributed on left and right sides; adjacent to the proximal phalanx of the finger, particularly the index finger, which was the most common location. Tumor locations are reported in Table 1.
Discussion
Fibroosseous pseudotumor of the digits occurs predominantly in the hands as a subcutaneous heterotopic, generally intramembranous, ossification with a fibroblastic stroma that mimics nodular fasciitis.
The observance of fasciitislike stroma in these collectively reactive digit fibroosseous lesions was previously made by Spjut and Dorfman [2] in florid reactive periostitis and by Dupree and Enzinger [1] in FOPD. Originally observed by Mallory [4] in 1933, this group of bone-producing digit
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Fibro-osseous pseudotumor of the digits: One of USP6-related fibroblastic/myofibroblastic tumors
2024, Annales de PathologieFibro-Osseous Pseudotumor Arising From Nail Bed of the Great Toe: A Rare Case of Recurrence
2022, Journal of Foot and Ankle SurgeryCitation Excerpt :The exact etiology of FOPT is unknown, but trauma or repetitive motion may play a role in its pathogenesis. It has been reported that up to 40% of these cases have a history of preceding trauma (1,2). In our case presented here, the patient had furniture fall on her toe 4 years before diagnosis.
Fibro-osseous pseudotumor of digits and myositis ossificans show consistent COL1A1-USP6 rearrangement: a clinicopathological and genetic study of 27 cases
2019, Human PathologyCitation Excerpt :In conclusion, we identified COL1A1-USP6 fusions in a majority of MO and FOPD cases, which now may be included in the USP6-related family of neoplasms. These lesions are notorious for mimicking various low-grade and high-grade soft tissue sarcomas [4-7,9,31]. The presence of USP6 gene rearrangement in the majority of NF, ABC, and MO/FOPD cases represents a very useful ancillary test, particularly in limited biopsies and in cases when clinical history and/or imaging studies are not available to the pathologist (which is a common scenario in our experience) [25,31,32].
Fibro-osseous pseudotumor of the digit: Case report and surgical experience with extensive digital lesion abutting on neurovascular bundles
2018, Annals of Medicine and SurgeryCitation Excerpt :The prognosis of this lesion, when completely excised, was favorable with a low risk of local recurrence (0–14% in various series) [17] and no evidence of malignant transformation. Incomplete excision however of the tumor was associated with a higher chance of lesion recurrence [1,4,5]. In this case however, complete excision was challenged by the extensive degree of tumor invasion.
Fibro-osseous pseudotumor of digits - Expanding the spectrum of clonal transient neoplasms harboring USP6 rearrangement
2018, Annals of Diagnostic PathologyCitation Excerpt :Radiologically, a soft tissue mass with variable mineralization is seen, often with development of a peripheral bone rim depending on duration [2,3]. Attachment to the periosteum or osseous surface has been rarely observed most probably being a secondary phenomenon due to the close relationship of tissues at these sites [3]. Because of the clinicopathological features lesions were linked to myositis ossificans and interpreted as being reactive [1-5].