Objective: Epithelioid sarcoma (ES) is a relatively rare soft tissue tumor that occurs in the extremities. Slow-growing, the seemingly benign appearance often results in misdiagnosis. Inadequate surgeries, as well as mistaken treatment as chronic ulcer or wound infection may lead to delayed recognition. ES is usually resistant to chemotherapy; thus, once metastasized, few options remain for its treatment. We reviewed upper limb ES cases that underwent treatment at our institution, all of which had experienced misdiagnosis. Patients: Ten patients (7 male, 3 female) were treated for ES in the upper limb between 1992 and 2015. The age at presentation was 6 to 88 years (mean, 36.7 ± 2.4 years). The initial tumor site was the digits in 4, palm in 2, forearm in 3, and upper arm in 1 case. All 10 had been treated previously at other institutions before diagnosis as a malignancy and subsequent referral to the orthopedic oncology division at our hospital. Results: The time between onset of symptoms and histological diagnosis was 3 months to 14 years (mean, 66.7 ± 6.2 months). The initial symptoms were a nodule in 5 cases (3 asymptomatic), persistent swelling after trauma in 2 cases, and a chronic ulcer in 1. Two cases were presented as neuropathies; a tumor at the wrist was diagnosed as Guyon canal syndrome and another in the forearm had caused anterior interosseous nerve palsy. Before recognition as a malignancy, 4 had been operated on as a benign tumor, and the others had been treated surgically as osteomyelitis, hematoma, wound infection, neuropathy, or chronic ulcer. None had evidence of metastasis on positron emission tomography (PET) scans at the time of referral to our services. Once correctly diagnosed, all cases received additional surgery. As adjuvant therapy, 3 received chemotherapy. Three were given radiotherapy; one at the primary site and 2 at sites of metastasis. At last follow-up, 5 cases were continuous disease free (CDF) and 2 were alive with disease (AWD); their follow-up was 19 months to 13 years and 9 months (mean, 95.9 ± 7.6 months). Five had experienced metastasis. Of the metastasis cases, 3 had died of disease. All 3 had been given radiotherapy and 2 were given chemotherapy. The duration of disease before death in these cases was 185, 197, and 30 months. There seemed to be no apparent correlation between the duration of symptoms and disease progression. A case treated 6 months after onset experienced multiple metastases and died 22 months after diagnosis, while cases of more than 10 years of duration are currently CDF or AWD. As surgery still seems to be the only curative option, early diagnosis and immediate treatment before metastasis are advisable. Conclusions: ES is not only rare, but does not always present as a typical sarcoma. Misdiagnosis is common, and in some instances, the mistake may be fatal. This tumor should be kept in mind when observing and treating a seemingly benign skin lesion that is taking time to heal.
