PEComa of the talus: a unique case of a soft tissue tumor within bone.

INTRODUCTION: Perivascular epithelioid cell tumor (PEComa) is a family of rare mesenchymal tumors composed of histologically and immunohistochemically distinctive perivascular epithelioid cells (PECs). These tumors have been described at multiple anatomic sites. PEComas presenting in bone are especially rare and they have been reported to be either primary or metastatic lesions. None of them is located at the level of the foot. PATIENT: We report on a case of primary bone PEComa of the talus, the first one to be published to the best of our knowledge. Treatment and result: Limb sparing surgical treatment has been done using intralesional tumor removal, burring and application of argon beam at the tumor walls and primary filling of the tumor cavity by bone cement with so far absence of any tumor recurrence documented by multiple histological sections at second look operation nine months after primary surgery, where cement has been replaced by autologous bone graft, and by subsequent follow-up. CONCLUSIONS: PEComa is a very rare tumor, and its presence in bone is especially rare. The here reported case of PEComa presenting at the level of the talus is, to the best of our knowledge, the first case to be reported in the literature.

Distribution patterns of foot and ankle tumors: a university tumor institute experience.

BACKGROUND: Bone and soft tissue masses of the foot and ankle are not particularly rare but true neoplasia has to be strictly differentiated from pseudotumorous lesions. Diagnosis is often delayed as diagnostic errors are more common than in other regions. Awareness for this localization of musculoskeletal tumors is not very high and neoplasia is often not considered. The purpose of this study is to provide detailed information on the incidence and distribution patterns of foot and ankle tumors of a university tumor institute and propose a simple definition to facilitate comparison of future investigations. METHODS: As part of a retrospective, single-centre study, the data of patients that were treated for foot and ankle tumors between June 1997 and December 2015 in a musculoskeletal tumor centre were analyzed regarding epidemiologic information, entity and localization. Included were all cases with a true tumor of the foot and ankle. Exclusion criteria were incomplete information on the patient or entity (e.g. histopathological diagnosis) and all pseudotumoral lesions. RESULTS: Out of 7487 musculoskeletal tumors, 413 cases (5,52%) of tumors of the foot and ankle in 409 patients were included (215 male and 198 female patients). The average age of the affected patients was 36 ± 18y (min.3y, max.92y). Two hundred sixty-six tumors involved the bone (64%), among them 231 (87%) benign and 35 (13%) malignant. There were 147 soft tissue tumors (36%), 104 (71%) were benign, 43 (29%) malignant. The most common benign osseous tumor lesions included simple bone cysts, enchondroma and osteochondroma. By far the most common malignant bone tumor was chondrosarcoma. Common benign soft tissue tumors included pigmented villo-nodular synovitis, superifcial fibromatosis and schwannoma whereas the most common malignant members were synovial sarcoma and myxofibrosarcoma. Regarding anatomical localization, the hindfoot was affected most often. CONCLUSIONS: Knowledge of incidence and distribution patterns of foot and ankle tumors will help to correctly assess unclear masses and initiate the right steps in further diagnostics and treatment. Unawareness can lead to delayed diagnosis and inadequate treatment with serious consequences for the affected patient.

Epithelioid sarcoma of the plantar fascia mimicking Morbus Ledderhose - A severe pitfall for clinical and histopathological misinterpretation.

Plantar fibromatosis, also known as Morbus Ledderhose, is a well known and frequently encountered disorder of the planta pedis. When conservative treatment fails, surgical therapy with complete resection is the therapeutical procedure of choice. Soft tissue sarcoma is a heterogeneous and rare malignant disease of the musculoskeletal system with over 50 histopathological subtypes which can potentially arise in any localization but is most commonly found at the extremities. Here, we report the case of an epithelioid sarcoma of the sole of the foot which was initially and repeatedly clinically and histopathologically misinterpreted as plantar fibromatosis, receiving insufficient resection and subsequently ending in amputation of the lower leg.

Distribution Patterns of Benign and Malignant Bone and Soft Tissue Tumors and Tumor-like lesions in the Hindfoot and Ankle: A 12.5-year Analysis.

BACKGROUND/AIM: Benign and tumor-like lesions of the hindfoot and ankle are common, whereas malignant entities are rare. Accurate evaluation and timely management of these lesions can be challenging, making it crucial to understand their incidence and anatomic localization. This study retrospectively analyzed the distribution of benign and malignant bone and soft tissue tumors in the hindfoot and ankle. PATIENTS AND METHODS: This study included patient data from a single center, such as age, sex, histologic diagnosis, and anatomic location over a 12.5 year period. RESULTS: Of the 105 cases reviewed, 19 cases (18.1%) were osseous lesions and 86 cases (81.9%) were soft tissue lesions. The latter were divided into 77 benign and 9 malignant cases, resulting in an overall malignancy rate of 8.6%. The most common osseous lesion was the intraosseous ganglion (n=12). The majority of benign soft tissue lesions (75.3%) were located in the hindfoot, with TGCT, schwannoma, and ganglion cysts being the most common types. The nine malignant cases were distributed among seven entities and were evenly distributed among both regions and sexes. Malignant cases had a higher mean age (59.2 years) compared to benign cases (40.8 years; p=0.001). CONCLUSION: Tumors, tumor-like lesions, and pseudotumors represent an important aspect of ankle pathology. The majority of focal masses and swellings are benign soft tissue or osseous lesions, but malignant entities can occur and may be mistaken for benign conditions. Preoperative imaging and histopathologic examination are essential, and preoperative presentation to a multidisciplinary tumor board is recommended in unclear cases.

Principles of Defect Reconstruction After Wide Resection of Primary Malignant Bone Tumors of the Calcaneus: A Contemporary Review.

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A Giant Cell Tumor of the Tendon Sheath of the Foot: A Rare Presentation.

A giant cell tumor of the tendon sheath (GCTTS) is a benign tumor that can occur in the joint synovium, bursae, or tendon sheath. It generally emerges in the tendons/synovium of the bones of the hand. It has unique characteristics, as noted in histopathological, clinical, and published literature. GCTTS has been reported across different age groups, with higher incidence observed in middle-aged adults. We present an unusual occurrence of GCTTS arising from the foot in a 54-year-old female who visited our medical facility with a history of swelling in her right foot for one year. Ultrasonography suggested a well-defined 5 x 4 cm lesion deep to the flexor tendon with possible intertarsal extension, which was managed surgically. This article represents a detailed understanding of GCTTS, emphasizing its benign yet locally aggressive nature and the complexities involved in its diagnosis and management.

Bilateral symptomatic Pacinian corpuscle hyperplasia of the adult foot.

Pacinian hyperplasia in the human body has been rarely described in the literature with most cases reported involving the hand (Fassola et al., 2019). This hyperplasia is considered a reactive lesion as opposed to a neoplasm (Satge et al., 2001), with the most common presenting complaint being pain and swelling (Fassola et al., 2019). In this study, a case of bilateral Pacinian corpuscle hyperplasia in the adult foot not previously described in the literature is presented.

A case of mistaken identity: classic Kaposi sarcoma misdiagnosed as a diabetic foot ulcer in an atypical patient.

BACKGROUND: The presentation of Kaposi sarcoma is divided into four known clinical subtypes. In this case report we describe classic Kaposi sarcoma in an African-American heterosexual, diabetic, seronegative human immunodeficiency virus male. Classic Kaposi sarcoma is rare in this patient demographic and can be easily misdiagnosed. CASE PRESENTATION: The patient presented with a lesion between the fourth and fifth digits of his right foot which was initially diagnosed as a diabetic foot ulcer. Despite local wound care, the lesion did not resolve. A shave biopsy was performed and histopathology findings were consistent with classic Kaposi sarcoma. CONCLUSIONS: The patient tolerated local radiotherapy well and had complete resolution of his pedal lesion. There have been emerging associations between diabetes and Kaposi sarcoma. As such, clinicians should have a low threshold when considering the biopsy of suspicious pedal lesions in patients with diabetes. The utilization of appropriate biopsy technique may lead to the diagnosis of classic KS tumors in populations outside of the current four widely accepted clinical subtypes.

Endoscopic resection and allografting for benign osteolytic lesions of the calcaneus.

BACKGROUND: Both unicameral bone cysts and intra-osseous lipoma of the calcaneus are rare entities which are mostly diagnosed due to unspecific heel pain, pathologic fracture or as an incidental finding. Minimally-invasive ossoscopy with endoscopic resection of the tumor followed by grafting can potentially minimize risks of open surgery and speed up convalescence. The objective of this study is to present a simple, safe and cost-effective surgical technique for endoscopic surgical treatment of benign osteolytic lesions of the calcaneus. DESCRIPTION OF TECHNIQUE: We present our modifications to previously described techniques of endoscopic curettage with a particular focus on intraosseous lipoma. The key point for grafting is the use of a funnel-shaped ear speculum facilitating the plombage with allogenic cancellous bone chips. PATIENTS AND METHODS: Between June 2013 and January 2015 ten consecutive patients underwent ossoscopy of the calcaneus. There were 4 cases of intraosseous lipoma and 6 cases of unicameral bone cyst. In a retrospective study, radiological results were analyzed using the Glutting-Classification, functional outcome was recorded with the AOFAS Hindfoot score. RESULTS: Radiographic follow-up and functional outcome showed good to excellent results. All lesions radiologically classified as "healed". AOFAS score (max. 100 pts) ranged from 74 to 100 (ø94.4 ± 9.3). CONCLUSIONS: This technique is a simple and safe procedure for benign osteolytic bone lesions of the calcaneus. Compared to its alternatives, grafting with allogenic cancellous bone might prove favourable in this localization for several reasons: Osteointegration, handling, availability and costs. Our preliminary investigations show promising results although further clinical and radiographic results are needed.

Glomus Tumors in the Foot: Case Series.

UNLABELLED: Glomus tumors are painful, benign neoplasms that frequently are associated with delayed diagnosis. Commonly in the hand, they rarely present in the foot. The purpose of this case series is to characterize the clinical presentation, radiology, pathology, and surgical outcomes associated with foot glomus tumors. We reviewed our pathology database for patients with foot glomus tumors diagnosed between 1995 and 2013. Medical records including physician notes, pathology, and radiology were reviewed. Eleven patients had foot glomus tumors excised at our institution during the study period. The mean age was 45.4 (range = 28-60) years. One patient was lost to follow-up. Mean follow-up for the remaining 10 patients was 44.7 (range = 3-142) months. Ten tumors were located in the subungual region, while 1 was located in the plantar pulp of the distal phalanx. All patients presented with pain. Point tenderness, cold hypersensitivity, and nail abnormalities were variably documented but frequently present. Four patients had had prior surgery for an ingrown toenail prior to presentation at our institution. Six patients had preoperative magnetic resonance imaging studies, which were diagnostic of glomus tumor in all cases except one. Radiographs failed to provide diagnosis in all 8 patients for whom they were obtained. Postoperatively, all patients had complete symptom relief with no recurrences.In conclusion, this case series demonstrates that foot glomus tumors frequently present with classic symptoms including pain, point tenderness, and cold hypersensitivity. When clinically suspected, magnetic resonance imaging should be obtained. Marginal excision results in symptom relief and cure. LEVEL OF EVIDENCE: Therapeutic, Level IV: Case series.