If asked to name a type of cancer, most people would likely reply with one of the more common cancers like bowel, breast, or lung. It is very unlikely they would say sarcoma, which is probably because it is so rare compared to other types of cancer, accounting for just 1% of all adult cancers. As a result, awareness of sarcoma is equally low.

Therefore, it is still important to be aware of sarcoma cancers and their signs and symptoms; as is the case with many other cancer types, the sooner sarcoma is diagnosed, the easier it is to treat, with better expected outcomes.

Sarcomas are derived from connective tissue and can be either soft tissue, bone, or gastrointestinal stromal tumours (GIST) and can affect any parts of the body and occur at any age.

Its rarity, it can be very rare for a GP or clinician in hospital to see a case in their working life. There are 15 soft tissue and bone tumours centres around the UK and, through NHS England cancer pathways, appropriate referral streams via suspected cancer two-week-wait to the sarcoma centres are in place for diagnostics and onward management in a Multidisciplinary Team (MDT).

A 72-year-old gentleman presented to his doctor with knee pain, especially at the back. He had a swelling of the back of his knee in the popliteal fossa and after clinical assessment, a soft tissue fluctuant swelling was found behind his knee. The working diagnosis was a Baker’s Cyst and he was sent for an ultrasound scan in the community.

The ultrasound scan was performed with the report by a Sonographer suggesting that there was a cystic-

looking lesion at the back of his knee and the likely diagnosis was a Baker’s cyst. The patient was reassured by the General Practitioner (GP) on the basis of this report and was discharged.

The patient continued to have ongoing left knee pain and was assessed by the local hospital as now after three months the whole leg was swollen and increasing pain. After clinical assessment, he was discharged with a presumed ruptured Baker’s cyst. No further investigations were performed.

He then continued to have pain and then sought an opinion from an Orthopaedic Surgeon, privately. Now at six months after initial presentation, he had significant left lower limb swelling from the distal posterior thigh, across the back of the knee (popliteal fossa) to his proximal calf. He had pain on weight bearing and had to use a walking stick. Examination revealed a tense solid mass coming from his popliteal fossa into his proximal calf.

Suspecting a possible tumour, the clinician arranged an MRI scan for further diagnosis which revealed a large soft tissue heterogenous mass in the popliteal fossa extending into the proximal calf (gastrocnemius muscles) suspected of a soft tissue sarcoma.

Following referral and review at the local Sarcoma Service MDT meeting, it was concluded limb salvage was not possible and that an above-knee amputation would be the only curative measure for sarcoma.

The patient had surgery and recovered but later developed distant spread with chest metastases. The patient subsequently claimed for delayed diagnosis by the GP and hospital with inappropriate escalation to further cross-sectional imaging. The basis of the claim was disproportionate symptoms to a Baker’s cyst, failure to re-examine, and inaccurate reporting of the ultrasound by the Sonographer.

A 42-year-old lady had been presented with left leg sciatica symptoms, and mild to moderate back pain for two months. She was assessed by the GP who had diagnosed her with having generalised lower back pain, possibly sciatica, and was prescribed analgesic and physiotherapy.

As her symptoms were not settling, she was subsequently referred for an MRI scan of her lumbar spine which was deemed normal and no obvious explanation for her sciatica was explained. The report was sent to the GP.

She was subsequently reassured by the GP and sent for further physiotherapy. Her symptoms persisted for another two months with persistent leg pain down to her ankle with paraesthesia and numbness with progressive weakness at the base of her-

foot, particularly on tiptoeing suggesting a sciatic nerve problem. In view of ongoing symptoms, she presented to her local A&E Department who assessed her and in view of her symptoms, repeated the MRI scan of the lumbar spine. Fortuitously, the MRI scan of the lumbar spine also included images of the proximal thigh on the left side. This included at the inferior aspect a possibility of a soft tissue mass.

This was red-flagged and subsequently escalated to the local orthopaedic surgeons who reviewed her in clinic and arranged an MRI scan of her thigh. Fortunately, the orthopaedic surgeons are also part of the local sarcoma centre, and she was urgently referred on the suspected cancer pathway.

The MRI scan of the left thigh revealed a large heterogeneous soft tissue 20cm mass in the posterior aspect of the proximal thigh. Features were consistent with soft tissue sarcoma and subsequent biopsies and discussion at MDT went on to having a wide resection.

The patient claimed that there was a delay in diagnosis with regard to her symptoms and absence of physical examination by the primary care physician.

The third case revolves around a soft tissue lump on the left thigh, which was initially several centimetres in size and referred with the skin changes to the local dermatologist. This was assessed by a Dermatologist who deemed this to be a sebaceous cyst. The patient wanted to have it excised and was subsequently listed for excision under local anaesthetic. An initial ultrasound scan was performed, which was suggestive of a sebaceous cyst.

When the patient presented for surgery, the lump had tripled in size to approximately 8cm with erythema and increasing pain. Local excision as planned was attempted by the Dermatologist.

During the procedure, it was difficult to excise and an attempt at best excision was made and sent to pathology which revealed a soft tissue sarcoma. She was subsequently referred onwards to the sarcoma centre locally for onward management. The patient claimed for incorrect diagnosis and diagnostics with the lack of consideration for a repeat scan especially MRI scan, in view that the lump has changed, increased in size and became more painful.

The issue of delayed diagnosis in cancer, in particular sarcoma, is a recurrent theme in medical negligence.

Sarcoma is a rare cancer hence difficulty in diagnosis can occur; however, as per NICE guidelines any lump which is getting bigger in size, deep and painful, or has a suspicious initial diagnostic should be referred for opinion to the local sarcoma centre as a suspected case.

The above examples highlight that there are many pitfalls in relation to sarcoma diagnosis, particularly in primary and secondary care.

Observations on previous sarcoma clinical negligence cases revolve around delayed referral of the patient for diagnostics or specialist input, absence of suspicion that this could be a soft tissue or bone sarcoma, not taking appropriate history with regard to the patient to suspect that this could be a sarcoma, and misinterpretation of diagnostics and delayed diagnosis.

Exploring these themes further:

One of the most common causes of litigation is delayed referral from the initial consulting clinician (e.g. GP, Consultant) or allied health professional, who may have just a lump, swelling, or even symptoms relating to possible bone cancer, which have led to the delayed referral.

It is imperative to take a detailed history and acknowledge that a lump which may be increasing in size, is bigger than 5cms or has re-occurred after previous excision as if this is not carried out, it can lead to further delays and a missed diagnosis of a possible potential cancer/sarcoma.

Pathways put in place along suspected cancer pathways across England to allow general practitioners to refer into secondary care and sarcoma centres for patients with suspected sarcoma. Failure to refer on these pathways may lead to further delays.

The indications for referral for a possible bone sarcoma includes X-ray showing suspicious findings, bone pain, and limb/joint swelling. Night pain in a limb or joint should not be ignored.

It is particularly important to note that such tumours are not missed in the paediatric and young adult population.
It is commonplace when asking patients about their journey that they state that they have seen multiple medical professionals with regard to their symptoms and reassured that nothing is wrong.

Failure to obtain a thorough history, partake in a thorough examination, or even refer for an ultrasound examination and/or X-ray (radiograph) in the first instance or even cross-sectional imaging can lead to missed or delayed diagnosis.

This may occur when the patient has had investigations, which have been incorrectly interpreted or reported. For example, an X-ray may have been performed and a lytic lesion or suspecting bone changes suggestive of bone cancer may have been missed.

The same errors can occur leading to misdiagnosis on ultrasound scans and MRI scans with misinterpreted imaging. Patients may present with swellings in their trunk or limbs during a separate medical presentation and it may not be addressed appropriately. For example causes of deep vein thrombosis (DVT) may be due to a compressive extrinsic mass not investigated. Sciatica can occur due to pelvic tumours. Note that the referrer only gets the investigation report so correlation with the patients’ clinical symptoms is an important consideration.

Patients in this type of category of potential delayed diagnosis maybe those who have not been referred for investigations or biopsy sooner. If the initial imaging has been misinterpreted or not picked up with a clinical history, this could be a soft tissue or bone sarcoma/tumour, then it leads to placing referral and subsequent diagnosis.

Inadvertent excision of a lump which turns out to be malignant can be classed as inappropriate surgery leading to what is commonly known in surgery as ‘whoops’. If the clinical assessment of the lump along with the history of the patient and investigations are not interpreted correctly, then the excision of a supposed benign lesion which turns out to be malignant without appropriate management and discussion in the MDT meeting, can lead to inappropriate excision leading to poor outcomes. Ultimately, it leads to an excision leaving tumour tissue behind, which subsequently leads to further surgery requiring a wider resection leading to inconvenience for the patient with further surgery and potential morbidity and mortality. This commonly occurs when clinicians do not suspect that there could be a tumour present which leads to patients refer to a specialist centre for recommended management.

Inadvertent excision of a lump which turns out to be malignant can be classed as inappropriate surgery leading to what is commonly known in surgery as ‘whoops’. If the clinical assessment of the lump along with the history of the patient and investigations are not interpreted correctly, then the excision of a supposed benign lesion which turns out to be malignant without appropriate management and discussion in the MDT meeting, can lead to inappropriate excision leading to poor outcomes. Ultimately, it leads to an excision leaving tumour tissue behind, which subsequently leads to further surgery requiring a wider resection leading to inconvenience for the patient with further surgery and potential morbidity and mortality. This commonly occurs when clinicians do not suspect that there could be a tumour present which leads to patients refer to a specialist centre for recommended management.

Metastatic bone disease is very common manifestation of any primary cancer (commonly from breast, kidney, thyroid, lung, prostate). Management of such lesions are foremost by the Oncologist and occasionally by orthopaedic surgeons.

The importance of such lesions is to ensure that these are not potential new solitary lesions which could be presenting as a primary bone sarcoma, but also to ensure that fracture is prevented.

Inappropriate management of such lesions may lead to: inadvertent ‘whoops’ surgery of potential bone sarcoma lesions which are presumed metastatic, fractures in such patients without input from musculoskeletal oncologists, or orthopaedic oncology input to occasionally resect and replace with a prosthesis or even fix. There are now national guidelines in relation to management of metastatic bone disease.

What is important, is that if a patient with the previous history of cancer presents with a solitary bone lesion in a long bone, it is important for the clinician not to assume that this is a metastatic lesion. This may be a primary bone sarcoma, and potential negligence may occur if wrong presumption. In the instance a lesion in the bone is inappropriately managed with surgery, it can lead to the spread of the primary cancer throughout the whole limb leading to subsequent amputation.

Delays in referral with suspected cancer patients can lead to poor outcomes with increased morbidity and mortality. This can subsequently lead to patients having poor and delayed treatment. This may lead to more aggressive surgery being undertaken such as amputation, where local control of limb salvage may be obtainable in such soft tissue and bone sarcomas. Metastatic bone lesions should not be presumed to be from another cancer that the patient appears they had without important diagnostics. It is important to take a history with the patient to ensure that symptoms and signs of soft tissue and bone cancer (sarcoma) are not missed. Delayed referrals remain the commonest cause for litigation in sarcoma.