[Resection margins in bone tumors: what is adequate?]

Grossing and reporting of bone tumor specimens in surgical oncology: Rationale with current evidence and recent updates

Primary bone tumors, including sarcomas, are rare tumors and require a multidisciplinary approach, including inputs from a radiologist, pathologist, medical oncologist, and surgical and radiation oncologist, for optimal management. Over the years, there has been a paradigm shift toward the treatment of bone sarcomas, from radical resections to conservative surgical procedures, to achieve improved clinical and functional outcomes. This has led to receiving and processing various types of specimens in orthopedic oncopathology. Grossing and reporting of bone tumors require expertise. This review focuses upon the types of biopsies, grossing techniques of various specimens in orthopedic oncology and reporting, with rationale and recommendations from pathologists, actively involved in reporting and pursuing a special interest in bone tumors, based on current evidence. Furthermore, there is a section on some of the updates in the diagnosis of bone tumors, based on the recent fifth edition of the World Health Organization classification of tumors of soft tissues and bone.

Ewing Sarcoma-Diagnosis, Treatment, Clinical Challenges and Future Perspectives

Ewing sarcoma, a highly aggressive bone and soft-tissue cancer, is considered a prime example of the paradigms of a translocation-positive sarcoma: a genetically rather simple disease with a specific and neomorphic-potential therapeutic target, whose oncogenic role was irrefutably defined decades ago. This is a disease that by definition has micrometastatic disease at diagnosis and a dismal prognosis for patients with macrometastatic or recurrent disease. International collaborations have defined the current standard of care in prospective studies, delivering multiple cycles of systemic therapy combined with local treatment; both are associated with significant morbidity that may result in strong psychological and physical burden for survivors. Nevertheless, the combination of non-directed chemotherapeutics and ever-evolving local modalities nowadays achieve a realistic chance of cure for the majority of patients with Ewing sarcoma. In this review, we focus on the current standard of diagnosis and treatment while attempting to answer some of the most pressing questions in clinical practice. In addition, this review provides scientific answers to clinical phenomena and occasionally defines the resulting translational studies needed to overcome the hurdle of treatment-associated morbidities and, most importantly, non-survival.

Chondrosarcomas of the small bones: analysis of 44 patients

BACKGROUND

Chondrosarcomas of the small bones of the hands and feet are uncommon and account for less than 2% of all chondrosarcomas in the skeleton; a 4.2% rate of malignant degeneration of enchondromas to secondary chondrosarcomas has been reported. We performed this study to assess the outcome of the patients with chondrosarcomas of the small bones. We hypothesized that the presumed better prognosis of chondrosarcomas in these locations could be biased as the majority of these tumors tend to be of lower grades and are removed when still small sized, and that less aggressive surgery has an adverse effect on local control MATERIALS AND METHODS: We retrospectively studied the files of 44 patients with chondrosarcomas of the small bones of the hands and feet. There were 23 female and 21 male patients with a mean age of 50.9 years (range, 6-86 years). The mean follow-up was 13 years (range, 5-40 years). We recorded the patients' details including gender and age at diagnosis, type and duration of symptoms, tumor location and histology, type of surgery and complications, and outcome (local recurrences and metastases).

RESULTS

The most common anatomical location for chondrosarcomas of the hands was the metacarpals and proximal phalanges. The most common presenting symptom was a slowly enlarging palpable mass. Overall, 36 chondrosarcomas were secondary to a pre-existing cartilaginous tumor. Patients with syndromes were affected in younger age compared to the others. The mean age at diagnosis was higher for higher grade chondrosarcomas. Overall, 13 patients (29.5%) experienced a local recurrence; the rate of local recurrence was higher after curettage regardless the histological grade of the tumors. After wide resection of the first local recurrence, five patients experienced local re-recurrence. Five patients (11.4%) experienced lung metastases, two patients at presentation. All these patients had a high grade chondrosarcomas. At the last follow-up, one patient with lung metastases died from disease, and another patient died from unrelated cause.

CONCLUSIONS

The patients with chondrosarcomas of the small bones of the hands and feet may have a dismal outcome if treated improperly. A careful treatment planning is required to avoid unnecessary amputations. Curettage is associated with a high rate for local recurrence that should be treated with a more aggressive surgical resection to avoid re-recurrences. Although the risk is low, the patients may develop lung metastases, especially those with higher grade chondrosarcomas, therefore, they should be staged and followed closely.

Assessment of Resection Margins in Bone Tumor Surgery

Limb salvage surgery is now the preferred procedure for bone tumor surgery. To decrease the risk of local recurrence, it is crucial to obtain adequate resection margins. The obtained margins must be evaluated postoperatively because they influence what treatment is given subsequently when margins are not adequate (e.g., surgical revision and radiotherapy). The study aims to evaluate margin assessment of tumor specimen by MRI compared to conventional histology (to establish the viability of using MRI) and assess the accuracy of a patient-specific instrument when narrow margins were aimed. The resection margins in 12 consecutive patients that were operated on for bone tumor resection were prospectively analyzed using three methods: MRI of the resection specimen, macroscopic evaluation of specimen slices, and microscopic pathological evaluation. The assessments were qualitative (R0, R1, and R2) and quantitative (distance in mm). MRI, macroscopic, and microscopic margins generated similar results for both the qualitative (all resections were R0) and quantitative assessments. The median error in safe margins was 2 mm with a surgical guide (PSI) and 5 mm without a surgical guide. Local recurrences were not detected after a mean follow-up period of 3.7 years (range, 2.1-5 years); however, four patients died during the study. In conclusion, MRI is a valuable tool for assessing safe margins. When specimens are not available for pathological assessment (e.g., extracorporeally irradiated autograft or autoclaved autograft), MRI could be used to evaluate margins. In particular, when tumor volume is high, MRI could also help to focus the pathological examination on areas of concern.

The impact of biopsy sampling errors and the quality of surgical margins on local recurrence and survival in chondrosarcoma

Purpose

To examine the frequency of computed tomography (CT)-guided biopsy sampling errors in chondrosarcomas, as well as the impact of these errors and the achieved surgical margins on local recurrence-free survival (LRFS) and disease-specific survival (DSS).

Material and methods

A total of 68 consecutive patients treated for chondrosarcoma from 2000–2015 were retrospectively reviewed with a minimum follow-up duration of 2 years.

Results

The primary location was at the extremities in 46 patients (67.6%) and at the axial skeleton in 22 patients (32.4%). Seven patients underwent planned intralesional curettage. Surgical margins were assessed in the remaining 53 patients and included 21 wide (39.6%), 25 marginal (47.1%), and seven intralesional (13.2%) resections. Biopsy sampling errors occurred in ten patients (14.7%). LRFS was 82.2±7.8% at 5 years and 76.9±7.8% at 10 years. An intact anatomical barrier was associated with the most preferable LRFS of 89±10.5% after 10 years. DSS was 79.2±8.5% at 5 years and 75.5±6.4% at 10 years. The metric distance of the surgical margin and the presence of a biopsy sampling error did not affect either LRFS or DSS.

Conclusion

Even though histological grading in chondrosarcoma is difficult, sampling errors in preoperative biopsies are relatively rare and do not adversely affect outcomes. The presence of an anatomical barrier has a greater impact on LRFS than the metric distance of the surgical margins.

Is superior tibiofibular joint resection necessary in extraarticular knee resection for sarcomas? A systematic review

Background

Sarcomas infiltrating the knee joint require extraarticular resection to achieve wide margins. Opinions differ as to whether the superior tibiofibular joint (STFJ) is part of the knee joint and should be removed in the course of extraarticular resection. Thus, we investigated the frequency of communication between the tibiofemoral joint (TFJ) and the STFJ, and the reported local recurrence rates (LRR) following extraarticular knee resection.

Methods

A systematic literature review on STFJ and TFJ communication and local recurrence rates following extraarticular knee resections was undertaken.

Results

Cadaver studies detected communication between the TFJ and STFJ in 10–64 % of the cases. Direct arthrography with physical loading verified a 100 % communication rate. Regarding the extent of extraarticular knee resection, two institutions where the STFJ was resected had a LRR of 4–8 %, while studies from another three where the STFJ was not routinely resected reported a LRR of 0–21 %.

Conclusions

Since the literature reports about a 100 % communication rate between the TFJ and the STFJ, resection of the STFJ in patients with sarcomas involving the knee joint would seem to be indicated, although it is not clear whether resection of the STFJ reduces local recurrence rates.