Tumours and tumour-like lesions in the foot and ankle

Osseous tumors of the foot, ankle, and lower leg: a cross-sectional observational study analysing 288 cases

BACKGROUND

Osseous tumors of the foot and ankle are rarely encountered in general orthopaedic practice and represent only 3 % of osseous neoplasms. It can be difficult to distinguish between benign and malignant lesions, leading to misdiagnosis. Delays in diagnosis are the main cause of litigation in sarcoma of the extremities. Poor understanding of how sarcomas present in this region can lead to inappropriate initial procedures, limiting options for limb salvage and increasing rates of local recurrence. Our aim is to improve understanding of these rare tumors to reduce misdiagnosis and decrease the occurrence of inappropriate or unwarranted procedures.

METHODS

We retrospectively analysed a prospectively maintained database of 288 new referrals to the West of Scotland regional musculoskeletal oncology service for osseous lesions of the foot, ankle and lower leg over a 10-year period. An analysis of patient demographics, presentation, anatomical location, diagnosis, classification, management and outcomes was performed.

RESULTS

Of all new referrals, 52.4 % were diagnosed with primary benign osseous tumors, 8.7 % with primary malignant osseous tumors, 9.7 % with metastatic osseous lesions, and 29.2 % pseudotumors. The most common primary benign tumor in our population was osteoid osteoma (18.5 %), primary malignant tumor was osteosarcoma (32 %) and metastatic osseous lesions were from small cell lung cancer primary (14.3 %). In the foot and ankle, malignant bone tumors most commonly presented in the distal tibia and fibula (20 %). Rest pain was the most common symptom at presentation in all groups, followed by swelling. The average duration of symptoms was 5 months for malignant lesions before primary referral.

CONCLUSION

Bone tumors in the foot and ankle remain a diagnostic challenge. We hope to have increased understanding of these rare lesions and have recommended a management protocol in order to reduce the number of inappropriate procedures performed, optimising clinical outcomes and reducing the cost of litigation to healthcare services.

LEVEL OF EVIDENCE

Level III- Cross-sectional observational study.

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.

Dorsal Medial Cuneiform Bony Outgrowth-Apophysis or Exostosis: A Case Report

CASE

Three female children (11-15 years) presented with painful dorsomedial medial cuneiform masses that did not improve after conservative treatment. Findings were consistent with a diagnosis of medial cuneiform apophysis. After surgical resection, no patients had recurrence, although one continued to have pain from a deep peroneal nerve sensory branch that was resected. One patient had an intramass physis identified.

CONCLUSION

When surgically removing dorsomedial cuneiform masses, surgeons should decompress overlying sensory nerve branches, detach and subsequently repair muscular attachments, and remove the entire stump to prevent regrowth because some of these masses may be apophyses and not exostoses.

Functional and oncological outcomes of limb-salvage surgery for foot and ankle tumors

BACKGROUND

Limb-salvage surgery has become the backbone treatment for musculoskeletal tumors in the last decades. However, limb-salvage with safe margins for tumors of the foot and ankle is challenging, due to the complex anatomy of this region. This study aimed to evaluate functional and oncological outcomes, complications, and local recurrence of limb-salvage procedures for tumors of the foot and ankle.

METHODS

This study was a retrospective review of 18 patients with primary tumors of the foot and ankle who underwent limb-salvage surgery between 1996 and 2015, with a minimum follow-up of 2 years. Clinical presentations, radiological and histopathological investigations, surgical procedures, functional and oncological outcomes, complications and local recurrences were analyzed. The Musculoskeletal Tumor Society (MSTS) scoring system was utilized for evaluation of the functional outcome.

RESULTS

With a mean follow-up period of 44.2 months, 7 males and 11 females with a mean age of 29.2 years were included. Nine patients were presented as recurrent cases. The most common location was forefoot in 7 patients. Synovial sarcoma was the histopathologic diagnosis in 7 patients. The final surgical margins were wide in 15 patients, wide-contaminated in one patient, and marginal in two patients. After resection, soft tissue reconstruction and wound coverage were done by soft tissue flaps in 4 patients. The mean MSTS score was 27.5. Four patients developed local recurrence, all of them were recurrent cases.

CONCLUSION

Limb-salvage surgery for foot and ankle tumors is an effective treatment option with good functional outcome.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

[Foot and ankle tumours : Part II: Malignant bone tumours and soft tissue tumours of the foot with differential diagnostic hints]

CLINICAL ISSUE

Both benign and malignant tumours are encountered in the foot and ankle. Due to their rarity, however, diagnosis is often uncertain. Usual criteria such as tumour size, invasiveness or pain fail to differentiate benign from malignant neoplasias.

STANDARD RADIOLOGICAL METHODS

Plain radiography and-due to the complex foot anatomy-CT are important in the diagnostic evaluation of primary bone tumours. In the case of soft tissue tumours, ultrasonography is used to identify ganglion cysts. Tumour evaluation and staging are then performed using MRI. Nuclear imaging comes into play when multifocal, metastatic or systemic spread of the disease is suspected or if a biopsy procedure is planned.

METHODICAL INNOVATIONS

For the role of dual-energy CT, please refer to part I. Whether dual-energy CT is suitable to assess bone marrow oedema patterns is still debated.

SPECIAL FEATURES OF FOOT AND ANKLE TUMOURS

Primary bone tumours generally present in the ankle or the hindfoot. Malignant bone tumours, e. g. chondrosarcoma, are primarily found in the latter. On the other hand, soft tissue tumours generally present in the mid- and forefoot regions.

ACHIEVEMENTS

While the radiologic diagnostic evaluation of pedal bone tumours is quite reliable, caution is urgently needed in the case of soft tissue tumours because there are many confusing differential diagnoses.

PRACTICAL RECOMMENDATIONS

Proper X‑ray examination of the foot (at least in two plains) or with special views according to bony pathology is needed. All soft tissue masses that are not cysts should be evaluated further. MRI remains the diagnostic modality of choice but never stands alone! Caution: Size and well-defined margins of pedal soft tissue tumours are not considered criteria regarding whether a tumour is malignant or not.

MRI imaging of soft tissue tumours of the foot and ankle

The majority of soft tissue lesions in the foot and ankle are benign. The aim of this review is to provide the reader with a comprehensive overview of the magnetic resonance imaging (MRI) characteristics of the most common benign and malignant soft tissue neoplasms which occur around the foot and ankle. This should enable the reader to formulate a reasonable differential diagnosis and, most importantly, to recognise those rare aggressive lesions that require further assessment and tissue biopsy.

Primary Tumor and Tumor-Like Lesions of Bones of the Foot: Single-Center Experience of 166 Cases

Primary bone tumors of the foot are rare lesions. The purpose of the present study was to evaluate the clinical manifestations, treatment modalities, and recurrences of various primary bone tumors of the foot from a specialized center for orthopedic oncology. Among 3681 musculoskeletal tumor cases, which were diagnosed and surgically treated in our hospital from 1983 to 2013, 166 primary tumor and tumor-like bone lesions of the foot (4.5%) were retrospectively reviewed regarding age, gender, localization, biopsy-revealed diagnosis, applied treatment modalities, follow-up period, and recurrence, if any. Of the 166 primary bone tumors of the foot, 155 (93.4%) were benign and 11 (6.6%) were malignant. The most common primary benign bone tumor was a unicameral bone cyst (57 of 155; 36.8%), and the most common malignant tumor was chondrosarcoma (7 of 11; 63.6%). The hindfoot was the most common location for both primary benign (104 of 155; 67.1%) and malignant (6 of 11; 54.5%) bone tumors of the foot. The results of our study have confirmed that the radiologic findings can be confusing owing to the structural and histopathologic features of the bones of the foot; thus, histopathologic diagnosis should be considered for foot involvement. Because the characteristics of the compartments in the foot allow for the rapid spread of malignant lesions, aggressive surgical management and wider resection are recommended to prevent recurrence and further spread.

A rare probable chondroblastoma of the calcaneus in a pre-Columbian subadult from Illinois

Discrete cystic or tumorous intraosseous lesions can arise from a variety of benign and malignant conditions as well as trauma and infection. They are clinically rarely observed in the calcaneus. A fourteen-to-seventeen-year-old subadult recovered from a Late Woodland (∼AD 800-1100) period mortuary context in the Mississippi River Valley of central Illinois presents with a single lytic intraosseous lesion on the posterior right calcaneus that bilaterally perforates the cortex. The lesion, although primarily anterior to the epiphyseal plate, does breach it. There is also a small perforation of the outer cortex of the epiphysis above the insertion of the Achilles' tendon. The lesion is well-defined with a primarily spongy cancellous interior margin. On the body of the calcaneus, there is periostosis and a slightly expansive endosteal reaction. Comparative radiographic assessments undertaken to differentially diagnose the lesion indicate that it was likely not malignant. Based on the posterior location, the radiographic signature, the bilateral cortical perforation and the breach of the epiphysis, the lesion is best interpreted as a chondroblastoma.

Aneurysmal bone cyst of the metatarsal: A case report

An aneurysmal bone cyst (ABC) is a rare, non-neoplastic, destructive, hemorrhagic and expansile lesion accounting for 1% of all bone tumors. This type of lesion predominantly affects long bones and vertebrae. ABC of the metatarsal is rare and only a few cases have been reported in the literature to date. The present study reports a rare case of ABC of the third metatarsal occurring in a 27-year-old male patient, who presented with repeated foot swelling that had lasted for ~1 year. Other clinical manifestations included limping, multiple lumps (defined as masses on or below the skin, as detected by imageological diagnosis) and progressively increasing local pain in his right foot. Magnetic resonance imaging of the right metatarsal revealed a segmented, expansile, multiseptated lesion with fluid-fluid levels. An en bloc resection was performed and the defect was replaced with a tricortical iliac autograft. Pathological analysis of the resected tissue suggested ABC. The present study aims to describe a case of ABC of the metatarsal, a condition that often poses a diagnostic challenge, and to underline the importance of radiological and histological examinations for the accuracy of that diagnosis.

Osteosarcoma of the Foot

A 40-year-old man presented with a large and painful right foot mass. The patient reported a history of a recurrent right foot mass treated elsewhere with 3 prior surgical excisions.

Role of (18)F-fluoride PET/CT over dual-phase bone scintigraphy in evaluation and management of lesions causing foot and ankle pain

OBJECTIVE

The purpose of this study was to assess the potential role of (18)F-fluoride PET/CT over dual-phase bone scintigraphy (DBS) in evaluation and management of lesions causing foot and ankle pain.

METHODS

(99m)Tc-HDP DBS and (18)F-fluoride PET/CT were performed in consecutive patients who visited rehabilitation department due to foot or ankle pain. Focal painful lesions in fore, mid, and hindfoot or ankle, and diffuse pain in foot were evaluated on DBS and (18)F-fluoride PET/CT (conclusive, inconclusive, nonvisible) and lesions on each modality were correlated. The clinical course was followed to see if the results of (18)F-fluoride PET/CT affected the decision of patient management.

RESULTS

Sixty-one painful lesions in 31 patients included 16 forefoot (26.2 %), 11 midfoot (18.0 %), 19 hindfoot (31.2 %), 6 ankle (9.8 %), and 9 diffuse footpain (14.8 %). Forty lesions (40/61, 65.6 %) were detected on DBS, including 21 conclusive diagnostic (21/40, 52.5 %), mainly including hindfoot lesions (n = 11). The inconclusive 19 lesions (19/40, 47.5 %) on DBS showed conclusive diagnostic findings on (18)F-fluoride PET/CT, mainly in fore and midfoot lesions (n = 15). Twenty-one painful lesions (21/61, 34.4 %) which were nonvisible on DBS revealed conclusive diagnostic findings on (18)F-fluoride PET/CT in 7 lesions (7/21, 33.3 %), including 5 hindfoot lesions. Fourteen nonvisible lesions (14/21, 66.7 %) on both modalities included all 9 diffuse painful foot lesions. Patient management was affected by findings of (18)F-fluoride PET/CT in 31 lesions (31/61, 50.8 %).

CONCLUSIONS

(18)F-fluoride PET/CT provided more confirmative diagnostic information in painful foot and ankle over DBS, and influenced patient management in many inconclusive or nonvisible cases on DBS. Increasing role of (18)F-fluoride PET/CT in benign diseases including foot and ankle pain is expected in the near future.

The hypermetabolic giant: 18F-FDG avid giant cell tumor identified on PET-CT

An 87 year-old white female presented with a two-year history of intermittent discomfort in her left foot. PET-CT identified intense18F-fluorodeoxyglucose (FDG) uptake corresponding to the lesion. Histology of a fine needle aspiration and open biopsy were consistent with a benign giant cell tumor (GCT) of the bone. GCT of bone is an uncommon primary tumor typically presenting as a benign solitary lesion that arises in the end of the long bones. While GCT can occur throughout the axial and appendicular skeleton, it is exceedingly uncommon in the bone of the foot. While 18F-FDG has been established in detecting several malignant bone tumors, benign disease processes may also be identified. The degree of 18F-FDG activity in a benign GCT may be of an intensity that can be mistakenly interpreted as a malignant lesion. Therefore, GCT of the bone can be included in the differential diagnosis of an intensely 18F-FDG-avid neoplasm located within the tarsal bones.

Lumps and bumps around the foot and ankle: an assessment of frequency with ultrasound and MRI

Benign and malignant tumours and tumour-like conditions frequently present as lumps in the foot and ankle. Although definitive histological diagnosis cannot be ascertained short of a biopsy, most entities can be confidently characterised on ultrasound and/or MRI. Masses in the foot and ankle present with lump, pain, paraesthesia, restricted mobility or a combination of these. In this review we have focussed on the relative frequency of masses in the foot and ankle that present as focal lumps, with a brief description of their typical appearance on ultrasound and MRI. Ganglions were the largest group in our series representing 24 % of the masses, followed by tendon- and ligament-related lesions and, bony lesions representing 16 % and 11 % of the masses respectively.

Giant osteochondroma of the talar neck

Giant osteochondroma is an uncommon entity and it is rare in the foot and ankle region. It is extremely rare to originate from the talus. In this case report we present a case of giant osteochondroma arising from the talar neck measuring 100 mm × 90 mm × 30 mm. It is unique because of the size, site and the age at presentation.

Pigmented villonodular synovitis of the ankle: radiologic characteristics

BACKGROUND

Pigmented villonodular synovitis (PVNS) of the ankle is a rare benign proliferative growth of the synovium. Studies of the radiologic characteristics of ankle PVNS are sparse.

METHODS

To characterize the radiologic features of ankle PVNS, five patients with histologically proven ankle PVNS were retrospectively studied. The features of their radiographs, computed tomographic scans, and magnetic resonance images were reviewed, with emphasis on the morphological features, extension, margin, bone involvement, signal intensity, and degree of magnetic resonance enhancement.

RESULTS

All five lesions were diffuse, affecting the ankle and distal tibiofibular joint; three lesions also involved the subtalar joint. Radiography demonstrated extrinsic bone erosions with marginal sclerosis of the involved joints in all of the patients, but computed tomography identified this much better than did radiography. Magnetic resonance imaging revealed multiple lobulated soft-tissue masses in all of the cases. These soft-tissue masses surrounded the flexor hallux longus tendon and were hypointense on T1-weighted images, with a heterogeneous signal in two cases and homogenous hypointensity in three cases on fat-suppressed T2-weighted images. In one patient who underwent gadolinium-enhanced imaging, the masses showed intense enhancement.

CONCLUSIONS

Magnetic resonance imaging is the best way to reveal ankle PVNS. Magnetic resonance imaging findings of predominant hypointensity on all pulse sequences and standard radiography findings of bone erosion with marginal sclerosis are characteristic.

Tumors of the foot and ankle: experience with 153 cases

BACKGROUND

Both primary and metastatic tumors in the foot and ankle have been reported as rare. The purpose of this study was to describe 153 cases of foot and ankle tumors from a 20-year experience in a tertiary referral center specializing in orthopaedic oncology. It is the largest reported series of both bone and soft tissue tumors in the foot and ankle.

MATERIALS AND METHODS

Between 1986 and 2006, a retrospective chart review was performed of a total of 2,660 tumors surgically treated in all anatomic sites by a single surgeon at a musculoskeletal tumor referral center.

RESULTS

One hundred fifty-three patients (5.75%) with bone and/or soft tissue tumors of the foot and ankle were treated. There were 84 women and 69 men. The patients' ages ranged from 1 to 84, with a median age of 30 and mean of 33.2. The tissue types included 80 soft tissue and 73 bone tumors. Overall, 60 (39.2%) were malignant, and 93 (60.8%) were benign. The most common diagnosis was giant cell tumor. In addition, giant cell tumor was the most common bone tumor, while pigmented villonodular synovitis and giant cell tumor of the tendon sheath were the most common soft tissue tumors.

CONCLUSION

The incidence of tumors of the foot and ankle in this series of a single surgeon over a 20-year practice was 5.75%. The results of this study reaffirm that awareness, correctly diagnosing, and appropriately treating or referring to an orthopaedic oncologist may help with an improved outcome for patients.

A case of an aneurysmal bone cyst of a metatarsal: review of the differential diagnosis and treatment options

Aneurysmal bone cyst localized to the metatarsus, while not unheard of, is rather uncommon. The differential diagnosis for this lesion can be challenging, particularly in regard to the possibility of the presence of other giant cells containing tumors of bone, such as giant cell tumor, giant cell reparative granuloma, Brown's tumor of hyperparathyroidism, and telangiectatic osteosarcoma. We report a case of an aneurysmal bone cyst localized to the third metatarsal in a 14-year-old girl who presented with limping, progressively worsening local pain, and swelling in her left foot. The differential diagnosis for her condition was extensive. Ultimately, an en bloc resection was undertaken and the defect was replaced with tricortical iliac autograft. Pathological analysis of the resected tissue was consistent with aneurysmal bone cyst. There was complete healing with no sign of recurrence 3 years after the surgery.

LEVEL OF CLINICAL EVIDENCE

4.

Pseudotumoral appearance of a ruptured epidermal cyst in the foot

We present a case of keratin granuloma due to a ruptured epidermal cyst, occurring in the foot, in a 52-year-old woman. The patient presented with a history of a slow-growing lump in the web space of the foot that had been present for over a year. Imaging appearances suggested a soft tissue neoplasm. Clinical presentation, radiological features and histopathological findings are described, and the relevant literature is reviewed.

Metatarsalgias: diagnóstico diferencial por meio da ressonância magnética

Várias lesões podem causar metatarsalgia, cujas manifestações clínicas podem ser inespecíficas. As imagens de ressonância magnética, associadas a outros métodos de imagem e dados clínicos, freqüentemente podem contribuir na detecção dessas lesões e possibilitar que um diagnóstico relativamente preciso seja considerado. Nosso objetivo é descrever e ilustrar, por meio de imagens de ressonância magnética, as principais doenças que causam metatarsalgia.