Aneurysmal bone cyst of the extremities. Factors related to local recurrence after curettage with a high-speed burr

Modern concepts of primary aneurysmal bone cyst

INTRODUCTION

Despite the long experience of radiologists, pathologists and orthopaedists with aneurysmal bone cysts (ABC), there is limited knowledge regarding the cause of the lesion and the optimal treatment. The pathogenesis of ABC remains unclear with theories ranging from a post-traumatic, reactive vascular malformation to genetically predisposed bone tumours. Recent genetic and immunohistochemical studies proposed that primary ABC is a tumour and not a reactive tumour-simulating lesion. The chromosomal analyses and some reported familial cases of this osteolytic bone lesion propose a hereditary factor in a presumably multifactorial pathogenesis.

MATERIALS AND METHODS

The imaging studies, even CT scan and MRI sometimes do not provide clearly diagnostic criteria for the diagnosis of ABC. The radiographically differential diagnosis between ABC and unicameral bone cyst (UBC) is sometimes not clear. Double density fluid level, septation, low signal on T1 images and high intensity on T2 images strongly suggest the bone cyst is an ABC, rather than a UBC.

CONCLUSION

Common methods of treatment vary considerably in the literature. The usual methods of treatment are curettage, resection, intracystic injections and embolization. Biopsy is imperative before any treatment. Ethibloc treatment remains highly controversial. For some authors Ethibloc injection can be recommended as the first-choice treatment excluding spinal lesions. A minimally invasive method by introduction of demineralized bone and autogenous bone marrow is able to promote the self-healing of a primary ABC.

Le kyste osseux anévrismal primitif : quoi de neuf en 2006 ?

The etiology of aneurysmal bone cyst is probably multifactorial. Recent progress in genetics and immunohistochemistry tends to prove that aneurysmal bone cyst is tumor and not a pseudo-tumor. Involvement of chromosomes 17p11-13 or 16q22 has been described. MRI is indispensable. Signs highly suggestive of aneurysmal bone cyst are: well-limited expansive bone lesion, low intensity T1 signal associated with high intensity T2 signal (liquid component), a low intensity peripheral line with enhancement after contrast injection, septal partitioning and fluid levels. Gadolinium injection is informative since it demonstrates the thick regular septal partitioning and the amorphous contents (lack of contrast uptake), a structure which is not seen in any other tumors, particularly malignant tumors. Plain x-ray and MRI contribute well to diagnosis but histological confirmation is always required. The debate on Ethibloc(R) remains open. For certain authors, this technique is an effective safe treatment which can be proposed as a first-line option. Ethibloc(R) should however be reserved for specialized teams because of the serious complications reported in the literature. A new treatment has also been reported to be promising, but further results will be required for confirmation. With this technique demineralized allogenic bone particles associated with autologous bone marrow are implanted in the cyst to achieve an osteogenic effect. This induces the cyst to pass from the destructive resorption phase to the repairing osteogenic phase. Curettage is not necessary. This method, which avoids extensive surgery and blood loss, is well adapted to difficult localizations such as the pelvis.

Aneurysmal bone cyst

OBJECTIVES

The purpose of this article is to discuss the natural history, treatment, and outcomes for patients with aneurysmal bone cysts (ABC).

METHODS

Review of the pertinent literature.

RESULTS

ABCs account for 1% to 2% of all primary bone tumors, usually present in the first 2 decades of life, and exhibit a slight female preponderance. The majority of patients are treated with curettage with local control rates ranging from approximately 70% to 90%. Almost all patients with recurrences are salvaged by one or more additional operations. A small subset of patients is treated with marginal or wide excision and almost all are locally controlled. A few patients with incompletely resectable, aggressive, and/or recurrent ABCs are treated with low-dose (26-30 Gy) radiotherapy (RT) and are locally controlled in approximately 90% of cases.

CONCLUSIONS

The mainstay of treatment is surgery and most patients are cured with one or more operations. A small subset of patients with incompletely resectable, aggressive, and/or recurrent ABCs may be cured with low-dose RT.

Current treatments of primary aneurysmal bone cysts

The management of aneurysmal bone cyst depends on the age of the patient, the location, extent, aggressiveness and the size of the lesion. In the light of their experience and a review of the literature of 1256 aneurysmal bone cysts, the authors analyzed various treatment modalities. Inactive lesions can heal with biopsy or curettage alone. In active or aggressive lesions, elective treatment usually consists of curettage, whether associated or not with bone grafting and local adjuvants. Aneurysmal bone cyst in young children do not seem more aggressive than in older children. In pelvic locations, the emergence of a few cases of spontaneous healing (even in active or aggressive lesions) encourages the adoption of clinical and radiological supervision for some months after biopsy when possible. In some cases, the localization and extent of the cyst are such that operative treatment is extremely hazardous. Selective arterial embolization has made a considerable contribution towards the therapeutic solution of such cases. For some authors, direct percutaneous Ethibloc injection can be recommended as the first-choice treatment except in spinal lesions. Nevertheless, the complications encountered in some series after percutaneous embolization of aneurysmal bone cyst with Ethibloc should encourage the use of Ethibloc injection not as an initial treatment but as a reliable alternative to surgery.

Prevalence of aneurysmal and solitary bone cysts in young patients

Aneurysmal and solitary bone cysts develop most commonly during skeletal growth. The objective of our epidemiologic study was to evaluate the prevalence, recurrence rate, and probability of recurrence-free survival for aneurysmal and solitary bone cysts in young patients. We did a population-based analysis of 141 histologically confirmed cases. Seventy-three patients with aneurysmal bone cysts and 68 patients with solitary bone cysts were registered. The annual prevalence was 0.32 per 100,000 individuals (range, 0-1.238) for aneurysmal cysts, with a 1.8:1 male to female ratio and a median age of the patients of 11.1 years (range, 1-19.7 years). For solitary bone cysts, the calculated annual prevalence was 0.30 (range, 0-0.963) with a median age of the patients of 1.1 years (range, 0.5-19.9) and a 1.96:1 male to female ratio. Recurrent lesions occurred frequently in young males. Secondary aneurysmal bone cysts were observed only in females. During skeletal growth, aneurysmal and juvenile bone cysts more often occur in males with a peak prevalence at approximately 11 years of age. A greater prevalence of aneurysmal bone cysts in young individuals is associated with skeletal growth and immaturity. Young age and male gender are associated with an increased risk of local recurrence.

Aneurysmal bone cyst of the index sesamoid

Sesamoid bone disorders are rare and usually are a result of trauma or degenerative causes. Tumors of the sesamoid bones of the hand are encountered less frequently. We report a case of an aneurysmal bone cyst of the radial index sesamoid of the hand. The tumor was treated successfully by sesamoid bone resection.

Aneurysmal bone cyst and giant cell tumor of bone of the hand and distal radius

Aneurysmal bone cyst and giant cell tumor of bone have historically been considered benign lesions that can behave in locally aggressive fashion. The clinical and pathologic findings share some common characteristics. When considering a radiographic differential diagnosis, these entities are usually considered together. There are some very distinct differences in potential aggressiveness and in response to treatment. This report summarizes current knowledge regarding these lesions when they occur in the hand and outlines current treatment methods.

Surgical treatment and recurrence rate of aneurysmal bone cysts in children

High recurrence rates have been reported after surgical treatment of aneurysmal bone cysts, ranging from 10-59%, and greater (five of seven) in children younger than 10 years. No previous study has focused specifically on recurrence as a function of age in a large pediatric study. The purpose of the current study was to review the outcome of current surgical techniques in the treatment of primary aneurysmal bone cysts in children and to determine if recurrence rates were higher in younger children, as proposed by some authors. This study included 45 children with primary aneurysmal bone cysts with more than 2 years followup after their first treatment using our current four-step surgical technique. The subjects were studied and classified on the basis of their age group (< or = 10 years of age or >10 years of age). The recurrence rate, and other parameters were determined after surgical treatment. Of the 45 children with primary aneurysmal bone cysts, 13 children were 10 years or younger and 32 were older than 10 years. Persistence or recurrence of the lesion requiring additional surgery occurred in three children in the younger age group and in five children in the older age group. The difference in persistence or recurrence rates based on age was not statistically significant. However, the persistence or recurrence rates are lower than previously reported (82% overall success rate after initial surgery).

Bone Cement Treatment for Aneurysmal Bone Cyst in a Dog

An eighteen month old female Doberman pinscher dog was referred to teaching hospital of Adnan Menderes University, Faculty of Veterinary Medicine with the complaint of right forelimb lameness for a month. On the basis of clinical, radiographical, scintigraphical, computed tomographical and histopathological findings, aneurysmal bone cyst was diagnosed. Surgical curettage and bone cement treatment were applied. The patient recovered after 12 months. This case proves that aneurysmal bone cyst, without osteolysis and/or damages to the surrounding tissues, may result in a good prognosis if curettage and treatment with bone cement are done.

Fibromyxoid areas and immature osteoid are associated with recurrence of primary aneurysmal bone cysts

AIMS

Primary aneurysmal bone cysts have a high recurrence rate following curettage. The aim of this study was to determine clinicopathological features associated with recurrence of aneurysmal bone cysts.

METHODS AND RESULTS

The clinicopathological features of 86 patients (37 males, 49 females, age range 5-62 years) with aneurysmal bone cysts were reviewed. Recurrence rates following curettage and excision were 32.7% and 5.6%, respectively (P = 0.028). The association of clinicopathological features with recurrence was studied in a subset of 45 patients treated by curettage. The presence of nodular fasciitis-like fibromyxoid areas [P = 0.033, odds ratio (OR) = 9.17, 95% confidence interval (CI) 1.06, 79.39] and immature osteoid with active osteoblasts (P = 0.041, OR = 3.7, 95% CI 1.03, 13.35) was significantly associated with an increased risk of recurrence. Clinical and radiological features were not associated with recurrence. In a multivariate analysis, the presence of immature osteoid was a better predictor of recurrence than radiological activity (hazard ratio = 3.18, 95% CI 1.04, 9.73, P = 0.043). There was no statistically significant association between radiological activity and histological features.

CONCLUSIONS

Aneurysmal bone cysts with nodular fasciitis-like fibromyxoid areas and immature osteoid with active osteoblasts are more likely to recur. Mention of these features in histopathology reports will help to identify patients who require closer follow-up. Lesions that are apparently radiologically inactive may show fibroblastic and osteoblastic proliferation and therefore may recur.