Symptomatic aneurysmal bone cysts of the spine: clinical features, surgical outcomes, and prognostic factors.

PURPOSE: The aim of the study was to report the long-term outcomes and analyze the potential prognostic factors that may contribute to symptomatic patients with aneurysmal bone cyst (ABC) of the spine undergoing surgical treatments. METHODS: A retrospective analysis of consecutive patients with ABCs of the spine was performed. The clinical features were reviewed, and the disease-free survival (DFS) and overall survival (OS) rates were estimated using the Kaplan-Meier method. Factors with p values ≤ 0.05 were subjected to multivariate analysis by Cox proportional hazards model to identify the independent prognostic contributors. p values < 0.05 were considered statistically significant. RESULTS: A total of 42 patients with ABCs of the spine were included in the study. All patients received surgical treatments. The mean follow-up period was 41.3 months (median 39.5, range 24-64). Local recurrence was detected in eight patients after surgery in our center, whereas death occurred in three patients. The estimated 5-year DFS and OS rate was 54.1% and 76.8%, respectively. The statistical analyses indicated that both en bloc resection and primary/secondary tumor status were independent prognostic factors for DFS. CONCLUSIONS: Secondary ABC status may be associated with worse prognosis, and en bloc resection remains the treatment of choice for ABCs with neurologic deficits or spinal instability of the spine, which is correlated with better prognosis for local tumor control. These slides can be retrieved under Electronic Supplementary Material.

Diagnostic value of histone 3 mutations in osteoclast-rich bone tumors.

Differentiating osteoclast-rich lesions of bone (giant cell tumor of bone [GCTB], chondroblastoma [CBA], and aneurysmal bone cyst [ABC]) can be challenging, especially in small biopsies or fine-needle aspirations. Mutations affecting codons 34 and 36 of either H3 Histone Family Member 3A (H3F3A) and/or 3B (H3F3B) are characteristically seen in GCTB and CBAs. We devised a simple assay to identify these mutations and evaluated its applicability for routine clinical diagnosis. One hundred twenty-four tissue specimens from 108 patients (43 GCTBs, 38 CBAs and 27 ABCs) were collected from the archives of the Calgary Laboratory Services/University of Calgary and Vanderbilt University Medical Center. Histology was reviewed by an expert orthopedic pathologist. A single base extension assay (SNaPshot) is used to interrogate each nucleotide in codons 34 and 36 of H3F3A and codon 36 of H3F3B. Final diagnoses were generated after re-reviewing cases and incorporating molecular findings. Of 43 GCTBs, 38 (88%) had an H3F3A G34W mutation; 35 of 38 CBAs (92%) had a K36M mutation in either H3F3B (N = 31; 82%) or H3F3A (N = 4; 11%); none of 27 ABCs had a tested mutation. Molecular findings changed the histomorphologic diagnosis in 5 cases (3 GCTB changed to ABC, and 2 ABC changed to GCTB). These findings support the diagnostic utility of mutational analysis for this differential diagnosis in certain challenging cases when clinicoradiologic and histomorphologic features are not definitive, particularly for distinguishing cellular ABC versus GCTB with secondary ABC.

Effect of adjuvant therapies on recurrence in aneurysmal bone cysts.

OBJECTIVE: The aim of this study was to define the effective factors such as surgical method, age and cavity filling materials on local recurrence in the treatment of aneurysmal bone cysts. METHODS: The study included 85 patients (mean age: 17.9 years) that received surgical treatment for primary aneurysmal bone cyst. Nine were treated with cyst excision and 76 with intralesional curettage. The intralesional curettage group was divided into 3 subgroups according to adjuvant therapies applied; the first group received no additional adjuvant therapy, the second group received additional high-speed burr and the third group received additional high-speed burr and alcohol/phenol adjuvant treatments. Bone graft or bone cement was used to fill in the cavity. Mean follow-up period was 107.5 months. Groups were analyzed statistically in terms of local recurrence. Onset of cyst in ages under 10 and 20 years were considered a negative prognostic factor and analyzed statistically. RESULTS: Local recurrence occurred in 10 (11.8%) patients. Mean duration between the initial operation and recurrence was 10 months. There was no significant difference in terms of local recurrence among the surgical treatment groups, adjuvant therapy groups, age groups and bone graft and bone cement groups. CONCLUSION: Careful curettage of the entire cyst wall remains the most important step in the intralesional treatment of aneurysmal bone cyst.

Aneurysmal bone cysts: do simple treatments work?

BACKGROUND: Primary aneurysmal bone cysts (ABCs) are benign, expansile bone lesions commonly treated with aggressive curettage with or without adjuvants such as cryotherapy, methacrylate cement, or phenol. It has been reported that occasionally these lesions heal spontaneously or after a pathologic fracture, and we observed that some ABCs treated at our center healed after biopsy alone. Because of this, we introduced a novel biopsy technique we call "curopsy," which is a percutaneous limited curettage at the time of biopsy, obtaining the lining membrane from various quadrants of the cyst leading to consolidation (curopsy = biopsy with intention to cure). QUESTIONS/PURPOSES: We asked whether (1) a curopsy results in comparable likelihood of healing of the ABC compared with more aggressive approaches involving curettage, (2) the two approaches differ in terms of the likelihood of recurrence after treatment, and (3) the two approaches differ in terms of complications after surgery. METHODS: Between January 1, 1999 and June 30, 2012, 221 patients with a diagnosis of primary ABC were registered in our oncology database. Patients presenting with a pathologic fracture and those seeking a second opinion were excluded. One hundred ninety patients were included in the study. One hundred two (54%) were treated with curopsy and 88 (46%) were treated with curettage after a core needle biopsy. Complete followups were available for 88% (90 of 102) and 93% (80 of 88) of patients in those groups, respectively. During that period, a curopsy was performed for all patients with benign bone lesions with imaging suggestive of classic primary ABCs and for whom the core needle biopsy simply showed blood with no solid component. Curettage after a core needle biopsy was reserved for histologically confirmed primary ABCs, lesions with impending fractures, large lesions, if the ABC was thought to be a secondary disorder, and patients for whom the curopsy failed. All patients were followed up until consolidation of the lesion (mean, 9.6 weeks, range, 3-25 weeks, 95% CI, 8.32-10.9 for curopsy; mean, 11.4 weeks, range, 8-32 weeks, 95% CI, 10.6-12.3 for curettage). The median followup for all patients was 14 months (range, 6-36 months). RESULTS: Of the 102 patients who had curopsy and observation, 83 (81%) required no additional treatment and the lesion resolved. Of the 88 patients who underwent curettage (with or without adjuvant therapy) after core needle biopsy, the success rate was 90% (79 of 88). Local recurrences in both groups (curopsy or curettage) were treated successfully with additional curettage in all but one case. Curopsy in comparison to curettage provided a mean shorter healing time (9.6 versus 11.4, p = 0.01) but there was a higher local recurrence and need for additional intervention rate (18.6% versus 10.2%, p = 0.04). There were no differences in the complications between the treatment groups. CONCLUSIONS: A curopsy is a novel biopsy technique that was successful in resolving ABCs in 81% of the patients in our study. Curopsy, as a biopsy technique, for ABCs needs consideration as it potentially minimizes the number of patients needing a second procedure (a core needle biopsy being the first) as is the current practice. Furthermore, it does not disadvantage the patient or surgeon should additional intervention be needed in the form of curettage with or without adjuvants. LEVEL OF EVIDENCE: Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Aneurysmal bone cyst secondary to giant cell tumor of the mobile spine: a report of 11 cases.

STUDY DESIGN: A retrospective analysis was performed. OBJECTIVE: To analyze the characteristics of aneurysmal bone cyst arising from giant cell tumor of the mobile spine and to discuss the outcome of corresponding surgical and nonsurgical treatment. SUMMARY OF BACKGROUND DATA: Giant cell tumors are generally benign neoplasms that exhibit aggressive behavior with a tendency to recur locally. Aneurysmal bone cysts are benign, highly vascular osseous lesions. Although both of them have been described separately in previous literatures, few reports have described aneurysmal bone cyst secondary to giant cell tumor of the mobile spine. METHODS: Between January 2004 and December 2009, 11 patients were identified with an aneurysmal bone cyst arising from giant cell tumor of the mobile spine. Four patients underwent subtotal tumor resection followed by radiotherapy, and the other 7 patients underwent total tumor resection. Patients with lesions located below T6 were treated with selective arterial embolization before surgery. Clinical data and the efficacy of surgery were analyzed via chart review RESULTS: Of the eleven patients identified for inclusion in this study, the average age was 33 months (range ∇ 14-65 months). The mean length of follow-up was 31 months. Seven patients kept disease-free during the follow-ups. The remaining four patients recurred and one died of local re-recurrence and lung metastasis. CONCLUSION: Unlike primary aneurysmal bone cyst, secondary aneurysmal bone cyst arising from giant cell tumor of the mobile spine has a more aggressive tendency to recurrence locally. Complete resection with systematic radiotherapy should be undertaken for the treatment of aneurysmal bone cyst secondary to giant cell tumor of the mobile spine, which is associated with a good prognosis for local tumor control. As complete or as radical an operation as possible should be performed at first presentation. The best chance for the patient is the first chance. Selective preoperative embolization is advised to minimize intraoperative blood loss.