Epithelioid sarcoma with muscle metastasis detected by positron emission tomography
© Sakamoto et al. 2008
Received: 29 May 2008
Accepted: 15 August 2008
Published: 15 August 2008
Epithelioid sarcoma is an uncommon high-grade sarcoma, mostly involving the extremities.
A 33-year-old man was referred to our institute with a diagnosis of Volkmann's contracture with the symptom of flexion contracture of the fingers associated with swelling in his left forearm. Magnetic resonance imaging (MRI) showed abnormal signal intensity, comprising iso-signal intensity on T1- and high-signal intensity on T2-weighted images surrounding the flexor tendons in the forearm. Diagnosis of epithelioid sarcoma was made by open biopsy, and amputation at the upper arm was then undertaken. [18F]-2-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) detected multiple lesions with an increased uptake in the right neck, the bilateral upper arms and the right thigh, as well as in the left axillary lymph nodes, with maximum standardized uptake value (SUVmax) ranging from 2.0 to 5.5 g/ml. Magnetic resonance imaging confirmed that there was a lesion within the right thigh muscle which was suggestive of metastasis, even though the lesion was occult clinically.
Increased uptake on FDG-PET might be representative of epithelioid sarcoma, and for this reason FDG-PET may be useful for detecting metastasis. Muscle metastasis is not well documented in epithelioid sarcoma. Accordingly, the frequency of muscle metastasis, including occult metastasis, needs to be further analyzed.
Epithelioid sarcoma was first described in 1970 . Epithelioid sarcoma is an uncommon slow-growing malignant soft-tissue mass, usually found in the extremities, particularly in the hand and foot. The tumor is known to be associated with a high incidence of local recurrence and metastasis. The tumor is mostly prevalent in young adults aged between 20 and 40 years old . The overall survival rates have been reported be 92.4%, 86.9% and 72.4% at 5, 10 and 15 years, respectively . Epithelioid sarcoma has a diagnostic problem clinically, because its symptoms are sometimes similar to benign conditions, including inflammatory or granulomatous lesions .
[18F]-2-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) has recently been used to assess various tumors. PET is evaluated using the standardized uptake value (SUV). An increased uptake of FDG-PET in cells reflects increased glucose metabolism as a result of various factors such as increased glucose transporters, high levels of hexokinase and a reduction in glucose-6-phosphatase [5, 6]. FDG-PET has been reported to be useful for distinguishing malignant tumors from benign tumors in the case of lung tumors , head and neck tumors  and breast tumors . As for bone and soft-tissue tumors, it has been reported that malignant tumors tend to have a higher SUV than benign tumors, with the cut-off point of SUV of 1.83 g/ml (sensitivity: 0.86, specificity: 0.42), 2.14 g/ml (sensitivity: 0.79, specificity: 0.52) and 3.23 g/ml (sensitivity: 0.57, specificity: 0.74) [10, 11]. The same research group also reported that the cut-off point of SUV in bone lesions was 2.3 g/ml (sensitivity: 0.73), and in soft-tissue lesions it was 2.8 g/ml (sensitivity: 0.88) .
In this report, we present a case of epithelioid sarcoma with the symptom of Volkmann's contracture characterized by a claw-like deformity of the hand and fingers associated with contracture of the muscles in the forearm. Furthermore, FDG-PET detected occult metastasis to the muscle clinically, in addition to metastasis to the regional lymph nodes.
A diagnosis of epithelioid sarcoma is challenging clinically, because epithelioid sarcoma is likely to be confused with a variety of benign and malignant conditions . Due to this diagnostic difficulty, it has been reported that the median interval between observing the initial symptoms, making a diagnosis, and starting treatment is 3.5 months, ranging between 1 and 36 months . In the current study, 7 months passed before a biopsy was undertaken for diagnosis, because the initial clinical diagnosis had been benign inflammatory lesion resulting in Volkmann's contracture. Furthermore, MRI failed to detect any obvious space-occupying lesion, and it was less suggestive of a solid tumor. Generally, in epithelioid sarcoma, necrosis within a neoplasm is a common finding. When the tumor spreads within a fascia or aponeurosis, it forms festoon-like or garland-line bands punctuated by areas of necrosis . The spread pattern of the epithelioid sarcoma seems to have caused the clinical symptoms of Volkmann's contracture in the current case.
SUV in FDG-PET of malignant bone and soft-tissue lesions has been reported to be higher than that of benign bone and soft-tissue lesions, with the cut-off point ranging from 1.83 to 3.23 [10, 11]. In another report, the cut-off point of SUV in FDG-PET in soft-tissue lesions has been reported to be 2.8 g/ml . In a previous study, FDG-PET was reported to be useful for verifying adjacent bone marrow infiltration in a case of epithelioid sarcoma, in which there are 2 foci in the right gluteus (SUVmax; 4.0–6.1 g/ml) and sacrococcygeal (SUVmax; 7.0–7.5 g/ml) regions . In the current case, the SUVmax of FDG-PET in the multiple metastatic lesions ranged from 2.0 to 5.5 g/ml. Taken together with the current case and the reported case, it might be possible that an increased uptake in FDG-PET is characteristic of epithelioid sarcoma.
In the current study, without FDG-PET, only the metastasis to the lymph nodes could be detected by CT, because metastasis to the muscle was occult clinically, even 3 months after the FDG-PET examination. The metastatic rate of epithelioid sarcoma has been reported to be 45%, and the most common sites of metastasis are the lung (51%), regional lymph nodes (34%), the scalp (22%) and bone (13%), while metastasis to the soft-tissue, including muscle, is thought to be less common . However, taking into consideration the clinically occult muscle metastasis in the current case, it is possible that clinically occult metastasis, such as to the muscle, is much more common than has been thought. There has been a report that the presence of lymph node metastases is not a significantly unfavorable factor , in contrast to other studies with conflicting results [4, 13–18]. It has also been suggested that lymph node metastases may be the first symptom of widely disseminated disease rather than a purely regional process .
In conclusion, we have reported a case of epithelioid sarcoma with the symptom of Volkmann's contracture. The current case should act as a reminder that Volkmann's contracture can be a symptom of epithelioid sarcoma in the forearm, and this reminder should help avoid a delay in the commencement of treatment. Multiple metastases to the lymph nodes and muscle had an increased uptake in FDG-PET, and the increased uptake may be representative of epithelioid sarcoma. Metastasis to the muscle tissue has not been well described so far. Further reports are necessary for the precise frequency of muscle metastasis to be ascertained. In that case, FDG-PET might be useful for detecting such metastasis.
Written informed consent was obtained from the patient and his family.
The English used in this manuscript was revised by Miss K. Miller (Royal English Language Centre, Fukuoka, Japan).
- Enzinger FM: Epitheloid sarcoma. A sarcoma simulating a granuloma or a carcinoma. Cancer 1970,26(5):1029–1041.View ArticlePubMed
- de Visscher SA, van Ginkel RJ, Wobbes T, Veth RP, Ten Heuvel SE, Suurmeijer AJ, Hoekstra HJ: Epithelioid sarcoma: Still an only surgically curable disease. Cancer 2006,107(3):606–612.View ArticlePubMed
- Casanova M, Ferrari A, Collini P, Bisogno G, Alaggio R, Cecchetto G, Gronchi A, Meazza C, Garaventa A, Di Cataldo A, Carli M, Italian Soft Tissue Sarcoma Committee: Epithelioid sarcoma in children and adolescents: a report from the Italian Soft Tissue Sarcoma Committee. Cancer 2006,106(3):708–717.View ArticlePubMed
- Enzinger FM, Weiss SW: Soft tissue tumors. St. Louis, CV Mosby 2001., 4th:
- Smith TA: FDG uptake, tumour characteristics and response to therapy: a review. Nucl Med Commun 1998,19(2):97–105.View ArticlePubMed
- Gallagher BM, Fowler JS, Gutterson NI, MacGregor RR, Wan CN, Wolf AP: Metabolic trapping as a principle of radiopharmaceutical design: some factors responsible for the biodistribution of [18F] 2-deoxy-2-fluoro-D-glucose. J Nucl Med 1978,19(10):1154–1161.PubMed
- Gupta NC, Maloof J, Gunel E: Probability of malignancy in solitary pulmonary nodules using fluorine-18-FDG and PET. J Nucl Med 1996,37(6):943–948.PubMed
- Lapela M, Grenman R, Kurki T, Joensuu H, Leskinen S, Lindholm P, Haaparanta M, Ruotsalainen U, Minn H: Head and neck cancer: detection of recurrence with PET and 2-[F-18]fluoro-2-deoxy-D-glucose. Radiology 1995, 197(1):205–211.PubMed
- Adler LP, Crowe JP, al-Kaisi NK, Sunshine JL: Evaluation of breast masses and axillary lymph nodes with [F-18] 2-deoxy-2-fluoro-D-glucose PET. Radiology 1993, 187(3):743–750.PubMed
- Tian M, Zhang H, Oriuchi N, Higuchi T, Endo K: Comparison of 11C-choline PET and FDG PET for the differential diagnosis of malignant tumors. Eur J Nucl Med Mol Imaging 2004,31(8):1064–1072.View ArticlePubMed
- Zhang H, Tian M, Oriuchi N, Higuchi T, Watanabe H, Aoki J, Tanada S, Endo K: 11C-choline PET for the detection of bone and soft tissue tumours in comparison with FDG PET. Nucl Med Commun 2003,24(3):273–279.View ArticlePubMed
- Chen YW, Huang MY, Chang CC, Lee CS, Liao YM, Chiu SS, Chang TT: FDG PET/CT findings of epithelioid sarcoma in a pediatric patient. Clin Nucl Med 2007,32(11):898–901.View ArticlePubMed
- Chase DR, Enzinger FM: Epithelioid sarcoma. Diagnosis, prognostic indicators, and treatment. Am J Surg Pathol 1985,9(4):241–263.View ArticlePubMed
- Prat J, Woodruff JM, Marcove RC: Epithelioid sarcoma: an analysis of 22 cases indicating the prognostic significance of vascular invasion and regional lymph node metastasis. Cancer 1978,41(4):1472–1487.View ArticlePubMed
- Bos GD, Pritchard DJ, Reiman HM, Dobyns JH, Ilstrup DM, Landon GC: Epithelioid sarcoma. An analysis of fifty-one cases. J Bone Joint Surg Am 1988,70(6):862–870.PubMed
- Callister MD, Ballo MT, Pisters PW, Patel SR, Feig BW, Pollock RE, Benjamin RS, Zagars GK: Epithelioid sarcoma: results of conservative surgery and radiotherapy. Int J Radiat Oncol Biol Phys 2001,51(2):384–391.View ArticlePubMed
- Evans HL, Baer SC: Epithelioid sarcoma: a clinicopathologic and prognostic study of 26 cases. Semin Diagn Pathol 1993,10(4):286–291.PubMed
- Spillane AJ, Thomas JM, Fisher C: Epithelioid sarcoma: the clinicopathological complexities of this rare soft tissue sarcoma. Ann Surg Oncol 2000,7(3):218–225.View ArticlePubMed
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