Malignant tumours of the foot and ankle

Advances of SS18-SSX fusion gene in synovial sarcoma: Emerging novel functions and therapeutic potentials

Synovial sarcoma is a rare type of soft tissue sarcoma that primarily affects adolescents and young adults, featured by aggressive behavior and a high potential for metastasis. Genetically, synovial sarcoma is defined by the fusion oncogene SS18-SSX arising from the translocation of t(X;18)(p11;q11). SS18-SSX fusion gene is the major driver of the oncogenic event in synovial sarcoma. SS18-SSX fusion protein, while not containing any DNA-binding motifs, binds to the SWI/SNF (BAF) complex, a major epigenetic regulator, leading to the disruption of gene expression which results in tumor initiation and progression. Emerging studies on the molecular mechanisms of SS18-SSX associated signaling pathway hold promise for developments in diagnosis and treatments. Advanced diagnostic methods facilitate early and precise detection of the tumor, enabling disease monitoring and prognostic improvements. Treatment of synovial sarcoma typically comprises local surgery, radiotherapy and chemotherapy, while novel managements such as immunotherapy, targeted therapies and epigenetic modifiers are explored. This review focuses on the recent studies of SS18-SSX fusion gene, epigenetic landscape, signaling pathways, diagnostic techniques, and relevant therapeutic advances, aiming to inhibit the oncogenic processes and improve outcomes for patients with synovial sarcoma.

Distribution Patterns of Tumors and Tumor-Like Lesions of the Forefoot and Midfoot A 12.5-Year Study at a University Hospital

BACKGROUND

Masses in the forefoot and midfoot are common reasons for medical presentation and can be caused by various pathological conditions. The challenge in clinical practice is to distinguish the multitude of trivialities from the few malignant entities and to arrive at a reliable clinical diagnosis in a reasonable amount of time with a moderate use of diagnostic tools.

MATERIAL AND METHODS

In a retrospective analysis, tumors, tumor-like lesions, and pseudotumors distal to the Chopart joint presented to our multidisciplinary university tumor board between January 2010 und June 2023 were analyzed concerning entity, location, age, and sex.

RESULTS

Of the 167 cases included, 18 were osseous and 149 were soft tissue lesions. Overall, the metatarsal region was most frequently affected, accounting for 42.5% of all cases. Osseous lesions showed a preference for the phalanges and soft-tissue lesions occurring more frequently in the metatarsal region. In total, 88.0% of all cases were benign. All 20 malignant cases derived from soft tissue, occurred in all sections of the forefoot and midfoot and comprised 13 entities. Most lesions affected middle-aged patients, but cases occurred in almost every age group.

CONCLUSION

In the examined patient population of a German university hospital, most cases were benign soft tissue lesions with a substantial share of pseudotumors and tumor-like lesions. However, the malignancy rate of 12.0% highlights the importance of differential diagnostic considerations. In cases of uncertain results, it is crucial to refer individuals with unclear masses to a specialized center for musculoskeletal tumor care early on in their treatment process.

LEVELS OF EVIDENCE

III.

Lessons learnt from an aggressive tumour masquerading as a neuropathic heel ulcer: a case report

Cutaneous malignant melanoma (cMM) can develop at any site, but one-third of cases primarily affect the lower extremities, with ankle and foot lesions representing 3-15% of all cases. However, cMM may become a clinical conundrum when it presents as chronic ulceration that is clinically indiscernible from other lower extremity ulcers in patients with diabetes. We present the case of a 71-year-old female patient with a longstanding history of diabetes, hypertension, obesity, chronic kidney disease and heart failure who presented to our hospital with a fungating heel ulcer. The lesion was initially managed in another hospital as a neuropathic diabetic foot ulcer (DFU), treated by multiple local wound debridement. However, the ulcer progressed into a fungating heel lesion that interfered with the patient's mobility and quality of life. Consequently, the patient was referred to our specialist diabetic foot service for further management. Excisional biopsy of the lesion disclosed a cMM. Positron emission tomography/computed-tomography scanning revealed hypermetabolic ipsilateral inguinal lymphadenopathy, and a right cerebral metastasis for which palliative chemotherapy was initiated. Immunotherapy was considered, but the patient died before it was started. Atypical foot ulcers in patients with diabetes warrant a careful diagnostic approach, especially for recalcitrant cutaneous lesions not responding to standard therapies. Conscientious management, without undue delay in obtaining a histopathological diagnosis, might lead to early diagnosis of melanoma and potentially more favourable outcomes. This case highlights the importance of consideration of atypical foot lesions, in general practice in addition to referral centres, to try to identify alarming features and act accordingly.

Ortho-oncoplastic surgery in foot and ankle: A narrative overview on reconstruction of soft-tissue defects after oncologic resections

INTRODUCTION

Malignant tumors of the foot are rare, and treatment strategies are challenging considering the complex anatomy of this area. In recent years, dramatic advances in technology and collaborations between different specialties (such as orthopedic, oncology, radiology, plastic, and vascular surgery) significantly changed the approach to complex malignant tumors without resorting to limb removal. The combination of the strengths of both orthopedic surgery and plastic surgery constitutes the modern definition of "orthoplasty." The aim of this review article is to provide treatment strategies that are available for reconstruction of foot and ankle in limb-salvage surgery after tumor resection, with a specific focus on microsurgical techniques in plastic surgery.

METHODS

We conducted a comprehensive search for relevant papers across PubMed, Scopus, Embase, and Web of Science. We included patient-based studies reporting on procedures for soft-tissue reconstruction with small and large soft tissue defects. Indications, pros and cons, and technique tips are discussed for each type of reconstructive technique.

RESULTS

The search was done using literature of the past 30 years (from 1990 to date), resulting in about 725 articles describing over 2000 cases. Cutaneous flaps included lateral supramalleolar flap, medial plantar flap, reverse sural neurocutaneous island flap, medial leg flap, and lateral leg flap. Free flaps included anterolateral thigh flap, radial forearm flap, latissimus dorsi flap, gracilis muscle flap, lateral arm flap, and rectus abdominis flap.

CONCLUSIONS

The orthoplastic approach in musculoskeletal oncology is a collaborative model of orthopedic and plastic surgeons working together, resulting in a higher rate of successful limb salvage in patients at risk for amputation. Protocols, biologic substitutes, and surgical techniques are largely improved in the last decades increasing the possibility of functional reconstruction. Microsurgical strategies represent the new frontiers in these demanding reconstructions.

Insights into the Distribution Patterns of Foot and Ankle Tumours: Update on the Perspective of a University Tumour Institute

The rarity of foot and ankle tumours, together with the numerous histological entities, presents a challenge in accumulating sufficient patients to draw reliable conclusions. Therefore, we decided to present an update of a retrospective analysis of their distribution patterns, comprising 536 cases of foot and ankle tumours presented to our tumour board between June 1997 and June 2023. Our aim was to provide a comprehensive overview of the prevalence and distribution patterns of benign and malignant bone and soft tissue tumours of the foot and ankle. A total of 277 tumours involved bone (51.7%). Of these, 242 (87.4%) were benign and 35 (12.6%) were malignant. In addition, 259 soft tissue tumours (48.3%) were found, of which 191 (73.7%) were benign and 68 (26.3%) were malignant. The most common benign bone tumours were simple bone cysts, enchondromas, osteochondromas, aneurysmal bone cysts, and lipomas of bone. Common benign soft tissue tumours included a tenosynovial giant cell tumour, haemangioma, plantar fibromatosis, schwannoma, and lipoma. The most common malignant soft tissue tumours were synovial sarcoma, malignant melanoma, and myxofibrosarcoma. In terms of anatomical location, the hindfoot was the most common site (28.7%), followed by the midfoot (25.9%), ankle (25.4%), and forefoot (20.0%). The distribution of benign entities often follows typical patterns, which may facilitate an early diagnosis even without biopsy (e.g., simple bone cyst, plantar fibromatosis). On the other hand, the distribution patterns of many rare or malignant entities are inconsistent. Individual soft tissue malignancies occur very sporadically, even over long periods of time and in specialized tumour centres. It is therefore important to recognise that any suspicious mass in the foot and ankle must be considered a possible malignancy until proven otherwise.

Tumours of the foot: A 10 years retrospective analysis

INTRODUCTION

The foot is a complex structure composed of several tissues, each of which can be the origin of the proliferation and development of the tumour. Most lesions about the foot are reactive or inflammatory, but some are true neoplasms.

METHOD

This is a retrospective analysis of 4997 patient records treated in the Orthopaedic Oncology Unit of University Malaya Medical Centre, Malaysia, between 1 January 2010 to 31 December 2020. Demographic data of 195 patients with foot tumours were analysed out of 4997 neoplasm patients.

RESULTS

There were 195 cases of foot tumours: 148 were benign, and 47 were malignant. 47 were bone tumours, 4 were metastases, and 144 were soft tissue tumours. Six patients succumbed to the disease, two cases of giant cell tumour (GCT) and one patient with synovial sarcoma had a recurrence. Treatment of foot tumours was wide resection in general. However, in metastasis cases, amputation was done. The majority of tumours were in the toes and dorsum of the foot. Soft tissue tumours of the foot occur in the elderly population in contrast to bone tumours, mainly in the second decade of life. The gender distribution was almost equal for foot tumours. Ganglion and Giant Cell Tumour of the bone are the commonest benign soft tissue and bone tumours. The most common malignant soft tissue and bone tumours are malignant melanoma and chondrosarcoma. The amputation rate is 5.64% the recurrence rate is 1.54%. Mortality rate is 3.08%. The MSTS score is 79%, and the TESS score is 76.23%.

CONCLUSION

Foot tumours are relatively rare, mostly originating from soft tissue and exhibiting a benign nature. Nonetheless, a noteworthy proportion-approximately a quarter of these tumours-demonstrate malignancy. The surgical interventions undertaken in managing these tumours and associated functional outcomes generally yield acceptable results.

RESECTION OF ANKLE TUMOR LESION AND RECONSTRUCTION WITH THE USE OF ALLOGRAFT

Reconstruction of the distal third of the tibia due to resection of a malignant tumor has some hindering factors, such as a thin subcutaneous layer, neurovascular bundles that cross compartments, prolonged operative duration, specific orthopedic material, and a trained multidisciplinary team. Allografting with material from tissue banks is part of this orthopaedic arsenal.

OBJECTIVE

To describe the protocol used at Instituto Nacional de Traumatologia e Ortopedia Jamil Haddad.

METHODS

Series of six cases subjected to resection with oncologic margins, allograft reconstruction, and use of a retrograde ankle nail as limb-salvage surgery. Three of the six patients were women, the lesions were on average 9.3 cm long, and the average operative duration was 3.25 hours.

RESULTS

The main short-term complication (≤ 30 days) was peroneal nerve palsy, while the main long-term complication (> 30 days) was surgical site infection (two cases). Consolidation of the two foci occurred in three patients, and two patients developed asymptomatic pseudoarthrosis of the proximal focus with consolidation of the distal focus.

CONCLUSION

Despite the complications, the proposed surgery gives patients the chance to preserve their limb in the face of immediate radical surgery. Level of Evidence IV, Case Series.

Review of Soft Tissue Masses of the Foot and Ankle: Magnetic Resonance Imaging Features

A large number of soft tissue masses affect the foot and ankle, with the majority being benign. Benign and malignant soft tissue lesions usually present as lumps, and it is important to differentiate between them to allow for optimal management. Imaging, in particular magnetic resonance imaging (MRI), can contribute to narrow the differential diagnosis of soft tissue masses of the foot and ankle by describing its exact location, internal signal characteristics, presence of enhancement, and its relation to adjacent structures. In this review, we review the literature to describe the most common soft tissue masses around the foot and ankle, focusing on the MRI features of the lesions.

Fibroma of the tendon sheath in the dorsum of the foot: A case report

Fibroma of tendon sheath (FTS) is a rare soft tissue tumor that usually occurs in the upper extremity. Moreover, of the few cases reported in the feet, nearly all occur in the plantar region. We report the case of a large FTS in the dorsum of the left foot that grew quickly into a 4 cm-diameter lesion. The 44-year-old Japanese man noticed the tumor incidentally one year before presentation and could not recall any possible cause. Physical examination showed an elastic hard mass that spread over the third to fifth metatarsal bones. MRI showed iso-intense signals with central hypo-intensity on T1-weighted images and hypo-intense signals on T2-weighted images. Since a biopsy did not reveal any malignant findings, the lesion was excised surgically. The tumor was found to be multilocular, encapsulated, and to arise from the extensor digitorum brevis tendon. Histopathology showed scattered spindle fibroblasts and slit-like vascular structures within the dense collagenous matrix. The tumor was diagnosed on the basis of the clinical, demographic, surgical, and histopathological findings as an FTS arising from the extensor digitorum brevis tendon. A review of the literature revealed seven cases of FTS of the dorsum of the foot, which indicates its rarity. More than one-half of these cases were from Japan. While the cause of FTS remains unclear, trauma has been implicated. We suggest that the cultural background of the patient, which could promote kneeling-induced dorsal foot trauma, may have contributed to the onset/progression of our case. Level of Clinical Evidence: 4.

Postoperative clinical and functional outcomes in patients with tumor and tumor-like lesion of foot and ankle

Background

Tumors and tumor-like lesions of the foot and ankle are relatively rare and their postoperative clinical outcome has not been well reported.

Methods

This study retrospectively reviewed medical records of all patients who underwent excision of tumors and tumor-like lesions of the foot and ankle from 2008 to 2020. Preoperative and postoperative clinical outcomes were evaluated by the Japanese Society for Surgery of the Foot (JSSF) scales (pain, function, and alignment).

Results

A total of 117 consecutive patients were analyzed in this study. Bone lesions accounted for 51 patients (benign: 45, intermediate malignancy: 1, malignant: 5), and soft tissue lesions accounted for 66 patients (benign: 57, intermediate malignancy: 2, malignant: 7). Four patients (8%) presenting with bone tumor and six (9%) soft tissue tumors resulted in recurrence. Eight (67%) patients with malignant lesions were alive continuously disease free and followed for a median of 50.5 (range: 18 to 82) months. Amputation at the first operation was done for five cases (33%) of malignant or intermediate malignancy (below-knee amputation: 1, Chopart disarticulation: 1, forefoot amputation: 3). Postoperative JSSF scores resulted in a significant 'positive' increase (bone lesion, 75.9 ± 13.7 to 91.4 ± 14.9, p < 0.001; soft tissue lesion, 84.7 ± 14.8 to 91.9 ± 12.5, p < 0.001). The score improvement in bone lesions was significantly higher than in soft tissue lesions (p = 0.003).

Conclusion

The surgical management of tumors and tumor-like lesions of the foot and ankle showed good post-operative functional outcomes with bone lesions exhibiting better results when compared to soft-tissue lesions.

Malignant Tumors of the Foot and Ankle

BACKGROUND

Surgical treatment is usually required for malignant foot and ankle tumors. In this study, we sought to review factors in treatment that may be associated with morbidity and mortality.

METHODS

All malignant foot and ankle tumors at our institution between April 1988 and April 2018 were retrospectively reviewed. The surgical modalities used and clinical outcomes of patients according to the anatomic location (Kirby zone) and clinical stage (Enneking system) of each tumor were described. Extent of surgical resection required, recurrence, and death rates were assessed.

RESULTS

Between April 1988 and April 2018, 80 patients with malignant tumors of the foot and ankle were treated at out institution. Mean age of patients was 42.6 (range, 3-89) years. Mean follow-up was 30.2 months (range, 24-120). Tumors were primary in 75 patients (94%) and metastatic from another organ in 5 patients (6%). Tumors originated from bone in 18 patients (22%) and from soft tissue in 63 patients (78%). Synovial sarcoma was the most common soft tissue tumor, and osteosarcoma was the most common osseous tumor.All patients had surgery to resect their tumor. Twenty-one (26%) had unplanned surgical procedures without initial biopsy at an outside institution prior to referral. Those patients were more likely to be treated with amputation or wide excison and free flap surgery (P < .01). The recurrence rate was 50% for the unplanned surgery group and 22% for the planned surgery group. Mortality rate was 10% for the unplanned group and 6% for the planned group. The recurrence and mortality rate was higher in the unplanned group (P = .03).

CONCLUSION

Our study suggests that unplanned initial surgeries are associated with higher recurrence and mortality rates and reinforces the notion that these patients should be referred for treatment at a center with specialized expertise in tumor management.

LEVEL OF EVIDENCE

Level, IV, retrospective case series.

Surgical excision of complex lipoma from the foot: A case report

Malignant soft tissue tumors of the foot and ankle are rare but diagnostic imaging and/or interventional biopsy are vital to establish the nature and grading of a suspicious tumor prior to definitive surgical intervention. The purpose of the study is to provide an account on how a symptomatic mass of the plantar aspect of the foot warranted a referral to a sarcoma center, highlighting the importance of having access to diagnostic imaging and a pathway to refer suspected cases to specialist centers. A single patient with a symptomatic soft tissue tumor of the plantar foot was referred from our service to the regional sarcoma center who considered to be benign, and therefore, open surgical resection was performed by our team. Histopathological analysis identified the excised mass as a lipoma. At 2 years, postoperatively there was no recurrence, and the patient presented with an asymptomatic foot. United Kingdom (UK) guidelines suggest that all soft tissue masses of suspicious nature, greater than 50 mm, deep seated irrespective of size, or fast growing lesions should be referred to a sarcoma unit prior to surgical management. European guidance identifies a threshold of 15 mm for a mass in the foot. Patients presenting with red flag symptoms irrespective of size of mass should be referred to a sarcoma center. Advanced imaging and multidisciplinary input to enable appropriate surgical planning is recommended for suspicious soft tissue tumors that present to the foot and ankle surgeon.

Functional outcomes in total talus reconstruction with triangular double-barrel free fibula flap following oncological resection: A retrospective case series review

BACKGROUND

With the advent of new techniques, foot salvage is feasible following talus oncological resection. As the reconstruction aims to achieve a pain-free, stable ankle for ambulation, biological limb reconstruction is the best option. This case series will evaluate the primary indications, complications, and functional outcomes of the reconstructed talus and highlighting the technical aspects of the surgery with a novel technique of triangular double-barrel free fibula flap.

METHODS

We performed a retrospective case note review of patients undergoing foot salvage surgeries and primary talus reconstruction with double-barrel free fibula flaps between 2009 and 2019. Patient demographics, aetiologies, operative details, complications, and outcomes were analysed. All patients underwent the same talar reconstruction technique whereby a wide-based triangular framework was created from two bony struts of the osteotomized fibula. The Musculoskeletal Tumour Society (MSTS) scoring system was used to analyse the short- to mid-term functional outcomes.

RESULTS

Four consecutive patients with aggressive benign and malignant tumours were identified. They consist of three males and one female, with a median age of 32 (range 27-39). Patients were followed up for a median duration of 60 months (range 24-132). Two flaps were complicated with venous thromboses; however, all were salvageable following re-explorations. All patients achieved solid bony fusion with good functional and aesthetic outcomes. The median MSTS score was 74.5% (range 66-76). No donor site morbidity and local recurrence were reported.

CONCLUSION

The triangular double-barrel free fibular flap is a good option for limb salvage following total talus resection, with good short- to mid-term functional and aesthetic outcomes.

Malignant neoplasms originating from the bones of the foot: Predilection of hematological malignancies and sex-related and ethnic disparities in amputation

PURPOSE

Neoplasms originating from the "small bones of the lower limb and the overlapping joints" are rare but portend a serious prognosis. Current study utilizes a population-based registry in the United States to characterize the malignancies of the foot.

METHODS

National Cancer Institute's Surveillance, Epidemiology and End Result database from 1975 to 2017 was queried to report incidence and survival data in 514 patients in the Uited States. Kaplan-Meier and Cox Regression were used to determine the prognostic factors affecting survival. Chi square test was used to assess the correlation.

RESULTS

Hematological malignancies constituted 14.8% of the entire cohort. Incidence of the foot neoplasms was 0.024 per 100 000 persons in 2017 and has not significantly changed since 1975 (p > 0.05). Disease-specific-5-year survival for the entire cohort was 73%. On multivariate analysis younger age groups, "localized" stage and extent of surgical resection were predictors of improved outcomes. A significant correlation was found between amputation with male sex and Hispanic ethnicity.

CONCLUSIONS

The current study analyzes data from population-based registry reporting incidence and survival data for patients with neoplasms of the foot. Independent prognostic factors include age, stage and extent of surgical resection. Amputation was found to be associated with male sex and Hispanic ethnicity.

Men who stare at bone: multimodal monitoring of bone healing

Knowledge of the physiological and pathological processes, taking place in bone during fracture healing or defect regeneration, is essential in order to develop strategies to enhance bone healing under normal and critical conditions. Preclinical testing allows a wide range of imaging modalities that may be applied both simultaneously and longitudinally, which will in turn lower the number of animals needed to allow a comprehensive assessment of the healing process. This work provides an up-to-date review on morphological, functional, optical, biochemical, and biophysical imaging techniques including their advantages, disadvantages and potential for combining them in a multimodal and multiscale manner. The focus lies on preclinical testing of biomaterials modified with artificial extracellular matrices in various animal models to enhance bone remodeling and regeneration.

Synovial Sarcoma: A Series of Small Tumors in Active Duty Service Members

Synovial Sarcoma is a soft tissue sarcoma with a propensity to imitate a benign neoplasm. It is most common in males 15-40 years old, typically presents as a slow growing painful mass, and often arises insidiously without alarm to the patient. Three patients with synovial sarcomas who had each undergone an index procedure to treat a small presumedly benign mass that was later identified as synovial sarcoma were reviewed. All three patients required re-excision of the tumor and tumor bed and are currently undergoing routine surveillance. All patients exhibited the classic translocation t(X;18) (p11.2; q11.2) and all were of the monophasic type. All lesions were less than 35 mm in greatest longitudinal dimension on MRI. None have experienced recurrences of synovial sarcoma to date. Healthcare providers should be aware of the synovial sarcoma's propensity to masquerade as a benign disease and the characteristic clinical and radiological findings. We advocate for a low threshold to obtain advanced imaging and consideration of a tissue diagnosis prior to excision. A referral to an orthopedic oncologist should be considered and biopsy should only be performed where the definitive treatment will take place if malignancy is identified.

Adjuvant Drug-Assisted Bone Healing: Advances and Challenges in Drug Delivery Approaches

Bone defects of critical size after compound fractures, infections, or tumor resections are a challenge in treatment. Particularly, this applies to bone defects in patients with impaired bone healing due to frequently occurring metabolic diseases (above all diabetes mellitus and osteoporosis), chronic inflammation, and cancer. Adjuvant therapeutic agents such as recombinant growth factors, lipid mediators, antibiotics, antiphlogistics, and proangiogenics as well as other promising anti-resorptive and anabolic molecules contribute to improving bone healing in these disorders, especially when they are released in a targeted and controlled manner during crucial bone healing phases. In this regard, the development of smart biocompatible and biostable polymers such as implant coatings, scaffolds, or particle-based materials for drug release is crucial. Innovative chemical, physico- and biochemical approaches for controlled tailor-made degradation or the stimulus-responsive release of substances from these materials, and more, are advantageous. In this review, we discuss current developments, progress, but also pitfalls and setbacks of such approaches in supporting or controlling bone healing. The focus is on the critical evaluation of recent preclinical studies investigating different carrier systems, dual- or co-delivery systems as well as triggered- or targeted delivery systems for release of a panoply of drugs.