He saw a general practitioner few weeks after the injury. Two ultrasounds were performed and the diagnosis of a large intramuscular haematoma was made. He was advised to manage the swelling with warm compress and simple analgesic.
He re-presented today because he noticed that the lump was enlarging and it started to affect his walking, however, there was minimal pain. In addition, he reported weight loss of around 10 kg and feeling fatigue over the last few months.
Physical examination revealed a large firm immobile mass in the medial-posterior aspect of the left thigh. There was significant oedema on his left leg. There was no evidence of neuromuscular compromise of the extremity.
An urgent MRI was performed. (Figure 1)
Figure 1
1. What does the MRI show?
Case continues: Patient was referred to an orthopaedic surgeon with a special interest in sarcoma. A biopsy confirmed the diagnosis of a myxofibroidsarcoma.
2. Could this lesion be associated with his injury?
3. Can the use of imaging differentiate a soft tissue sarcoma from a benign haematoma ?
4. Is the delay in diagnosis of soft tissue tumour common?
5. How would you manage this patient?
1. The MRI showed a large intra muscular mass with heterogeneous enhancement measuring in the posteromedial thigh. It rose the possible diagnosis of a sarcoma.
2. An association between trauma and soft tissue sarcoma has been suggested for over 200 years.(5) Currently, there is no evidence to say that the relationship is causal. The usual history is of a traumatic incident occurring shortly prior to the awareness of the mass. Because of the relatively short time frame, we think that the trauma merely brings the patient's attention to the mass. (5)(7).
3. Even with the advances in modern technology, we cannot use imaging to safely differentiate a soft tissue sarcoma from a haematoma. (2,5,7,8). Gomez et al reported three cases similar to our case study. All three patients had history of trauma prior to consulting their family physicians with lumps. They had MRIs and CTs, and were all initially reported as haematomas. This highlights the difficulty in differentiating malignant tumour from a benign haematoma using imaging alone. The imaging results need to be interpreted in the context of clinical history and examination. When there is enough clinical suspicion of a soft tissue sarcoma, patient should be referred to a specialist unit for biopsy. (8)
4. The delay in diagnosis of soft tissue sarcoma is a common problem. Many studies were conducted in an attempt to identify the sources of delay. (2,3,4) The identified sources of delay include patient delay in presentation, mis-diagnosis, and waiting for investigations such as imaging and biopsy. The average time frame between the onset of symptoms to patient presentation is around 12 months, and the average time frame between patient presentation to referral to a specialist unit is 13.5 months.
Sarcoma is a rare tumour. There are around 800 new cases diagnosed in Australia per year. Most general surgeons or general practitioners will only encounter a soft tissue sarcoma once or twice in their careers. Therefore, it is important to be vigilant and treat any lump greater than 5 cm or deep to the fascia as sarcoma until proven otherwise.
5. Studies have shown that early referral to a specialist unit improves survival rate and treatment outcome. Imaging and biopsies at non-specialist units are often inadequate and further delay the diagnosis. Poor biopsy techniques can potentially complicate future surgical excisions. Hence, an early referral for biopsy or management is recommended.
Case continue
Further imaging at the specialist unit showed pulmonary metastases. He underwent radiotherapy and definite surgical excision. The surgical excision was of palliative intent due to his pulmonary metastases. At the time of writing, he had returned home and recovered well from his surgery. He will require regular review and ongoing surveillance .
Key points:
- Any lumps greater than 5cm in diameter or deep in fascia should be treated as sarcoma until proven otherwise.
- Imaging results need to interpreted in the context of clinical history and examination. A biopsy is required to exclude soft tissue sarcoma.
- An early referral to a specialist unit provides the best survival rate and treatment outcome.
References:
Cancer Council Australia Sarcoma Guidelines Working Party. Clinical practice guidelines for the management of adult onset sarcoma.
Sydney: Cancer Council Australia. [Version URL: http://wiki.cancer.org.au/australiawiki/index.php?oldid=138276, cited 2017 Apr 11].
Available from: http://wiki.cancer.org.au/australia/Guidelines:Sarcoma
2. Ashwood N, Witt JD, Hallam PJ, Cobb JP. Analysis of the referral pattern to a supraregional bone and soft tissue tumour service. Ann R Coll Surg Engl 2003 Jul;85(4):272-6 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/12855033.4. Stiller CA, Passmore SJ, Kroll ME, Brownbill PA, Wallis JC, Craft AW. Patterns of care and survival for patients aged under 40 years with bone sarcoma in Britain, 1980-1994. Br J Cancer 2006 Jan 16;94(1):22-9 Abstract available at http://www.ncbi.nlm.nih.gov/pubmed/16317433
5. Soft tissue sarcomas of the extremities. Blake A. Morrison. Available at
6. Uptodate pathogenetic factors in soft tissue and bone sarcomas
7. http://www.bcmj.org/article/soft-tissue-sarcomas-extremities-how-stay-out-trouble
8. High grade sarcomas mimicking traumatic intramuscular hematoms: a report of three cases. Pablo Gomez and jose Morcuende Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1888428/pdf/1555-1377v024p106.pdf
