A 68-year-old male was admitted to the department of orthopedic surgery with swelling at his left wrist joint. The patient underwent plain radiographies, CT and MRI of the left wrist.
A 68-year-old male presented at the department of orthopedic surgery with swelling at his left wrist joint. The patient mentioned that he had been treated for the last 6 months with dexamethasone and methotrexate because his symptoms had been attributed to rheumatoid arthritis. The persistence of the symptoms led to further observation. Clinical examination revealed swelling of the left wrist joint, especially at the volar aspect with sensitivity at movements. There were no signs of infection or indications of epidermis invasion. Atrophy of the arm and the forearm muscles was present and a painless hard lymph node was palpated at the left axilla. The patient underwent plain radiographies, CT and MRI of the left wrist. On plain radiographies there was swelling of the soft tissues of the left wrist joint and concomitant osteopenia and osteolysis of the wrist bones and the distal part of the ulna and the radius (fig1). CT demonstrated an infiltrative soft tissue mass at the wrist especially at the volar aspect extending from the base of the metacarpal bones to the distal part of the radius and the ulna with concomitant osteoporosis and osseous destruction of the aforementioned bones (fig2). The MRI confirmed the findings. The soft tissue mass was hypointense on T1WI and after contrast medium administration there was mild heterogeneous enhancement (fig3a,b). The patient underwent surgical excision of the tumor and the cytological examination revealed acidophilic epithelioid cells and striated muscle fibers (fig 4). The diagnosis established was epithelioid sarcoma of the tendon’s sheath.
Epithelioid sarcoma [ES] is a rare, high-grade soft tissue sarcoma associated with a high risk of local recurrence, regional or distant metastases. It was first described as a distinct entity by Enzinger in 1970. Nowadays ES is classified as a neoplasm with well recognisable microscopic and ultrastructural features but its histogenesis continues to be elusive. ES occurs predominantly in young adults in distal parts of the extremities, especially on fingers, palms, feet and forearms. Less frequently it occurs on thighs, lower legs, buttocks and the chest wall. Substantially rarer is its atypical localization, penile, vulval or lingual. The tumor usually presents as single or multiple ulcerated nodules. Less frequently it is located deeper and fixed to the tendons, tendon sheath and fascia. Rarely grows along the neurovascular bundles.
The microscopic picture of typical ES variants reveals proliferating epithelioid or spindle-shaped cells, sometimes in palisade arrangement around a central necrotic area. Final ES diagnosis requires presence of cytoceratin, EMA, and vimentin in neoplastic cells, as confirmed by immunohistohemical reactions.
On plain radiographies there can be focal cortical thickening or stippled soft tissue calcification. MRI signal characteristics are variable and reflect degrees of cellularity and the presence of necrosis, hemorrhage and fibrosis. The differential diagnosis must include both benign and malignant lesions. Benign lesions include tendon sheath xanthomas, nodular synovitis and fibromas. All these entities do not present bone invasion. Due to its proximity to tendons it may be confused with other soft tissue synovial lesions especially synovial sarcoma.
The treatment consists of radical excision of the tumor and lymph node dissection.
We present this case because our patient was at the age of 68, when most of ES present at the age of 10 to 35, and the mass was large with extensive bone destruction at the time of the examination.
Epitheloid sarcoma of the tendon's sheath
Based on the patient's left wrist X-ray, CT, and MRI images:
Given the patient’s older age (68 years), significant tissue destruction, and the radiological findings, the following diagnoses or differential diagnoses should be considered:
Based on the radiological features—significant bone destruction, a large soft tissue tumor-like lesion—and histopathological findings (tumor cells displaying epithelioid or spindle formations, central necrosis, and positive immunostaining for cytokeratin, EMA, and Vimentin), the most likely diagnosis is: Epithelioid Sarcoma.
Because this tumor grows invasively and has a high risk of local recurrence and distant metastasis, active treatment is required. Further confirmation may be obtained through expert pathological consultation or additional testing for specific markers if necessary.
In line with current knowledge and relevant clinical guidelines, the following are suggested:
Particular attention should be paid to bone and soft tissue healing to maintain joint mobility without excessive traction on the tissue. If the patient also has diabetes, hypertension, or other chronic conditions, further individual assessment of exercise intensity is needed to ensure safety.
Disclaimer: This report is for reference analysis only and cannot replace a professional physician’s in-person diagnosis or treatment advice. If there are any doubts or changes in the patient’s condition, please seek medical attention or contact professional healthcare personnel promptly.
Epitheloid sarcoma of the tendon's sheath
