SEARCH

SEARCH BY CITATION

Keywords:

  • hip and knee pain;
  • synovial sarcoma;
  • tophaceous gout

Abstract

  1. Top of page
  2. Abstract
  3. CASE PRESENTATION
  4. SUMMARY
  5. ACKNOWLEDGMENT
  6. REFERENCES

Gout is a common rheumatologic condition with characteristic clinical presentations during the acute arthritis and chronic tophaceous stages. Because of this, there is a tendency to overlook rare but important conditions which are independent of, but can co-exist with gout. This case of severe hip and knee pain in a patient with tophaceous gout takes the reader on a problem-solving exercise which simulates the analytical processes and decisions made in the clinic.


CASE PRESENTATION

  1. Top of page
  2. Abstract
  3. CASE PRESENTATION
  4. SUMMARY
  5. ACKNOWLEDGMENT
  6. REFERENCES

A 57-year-old man had recurrent episodes of acutely painful mono- or oligo-arthritis over the past 20 years, and was diagnosed with tophaceous gout 2 years before presentation. He had been irregularly taking colchicine and allopurinol, and an occasional non-steroidal anti-inflammatory drug (NSAID) for gout flares. The last gout attack was 3 months previously, involving both knees and the right wrist, documented by the presence of monosodium urate (MSU) crystals by polarized microscopy of synovial fluid. He improved on a single injection of depot methylprednisolone, analgesic combination of paracetamol with tramadol, and colchicine; allopurinol was resumed 2 weeks later. There was also an assessment of NSAID-induced nephropathy based on mild azotemia (serum creatinine 1.9 mg/dL); ultrasonogram showed normal-sized kidneys and no evidence of lithiasis. He occasionally took beer averaging 500–1000 cc/month over the previous 30 years. There was no personal nor family history of hypertension, diabetes mellitus or malignancies.

Discussion

Gout is a common rheumatic condition seen at the clinic, typically presenting as intermittent attacks of arthritis, and invariably accompanied by serum uric acid elevation; tophaceous deposits are pathognomonic. Although the azotemia was assessed as NSAID-induced nephropathy, renal complications directly related to hyperuricemia (with sonographically normal-sized kidneys) such as urate nephropathy or interstitial nephritis, are other possibilities. Regardless of the underlying cause, it is prudent to avoid further renal injury, and effectively treat the acute inflammation with short course corticosteroids, colchicine (maximum 1 mg/day), adjunctive opioid analgesics, and cold packs. When the acute attack has subsided, the next step is to maintain the patient on serum urate-lowering agents like allopurinol and reinforce patient education to adhere to both pharmacologic and non-pharmacologic prescriptions, such as a balanced diet and healthy lifestyle.1

Clinical data

Two months before admission, he began to experience vague, nagging right knee pains not related to activity, transiently relieved by tramadol. The pain later progressed to also involve the right hip and inguinal area, was worse at night and was accompanied by weight loss of approximately 5 kg within 2 months. A month later, an enlarging, painful right inguinal mass was noted causing difficulty in ambulation. NSAIDs and other analgesics offered temporary pain relief. There was no history of trauma, fever, change in bowel habits or urinary symptoms. He was admitted to the hospital.

Physical examination showed a wheelchair-borne man of medium build, with normal vital signs, who appeared wan and pale. There were scattered tophi on the elbows and feet without any sign of inflammation, and there was no active synovitis in the peripheral joints. He kept the right hip at 45° flexed position, and any attempt to perform internal and external rotation and extension of the right hip joint elicited severe pain. There was a 5 cm × 4 cm fixed, firm, slightly tender non-pulsatile mass along the medial aspect of the proximal anterior right thigh just beneath the inguinal line, with some atrophy of the quadriceps and hamstring muscles. Examination of the right knee was entirely normal, as was the remainder of the physical exam.

Discussion

There are two clinical issues here. The first is the persistent knee pain in an apparently normal knee. This is likely to be referred pain from the hip due to the obturator nerve supplying the hip joint and giving a branch to the knee joint. Furthermore, in contrast to the knee, the hip joint and its peri-articular structures are relatively deep and therefore less accessible to manual physical examination. It is thus important to examine the hip in any patient with knee pain.

The other issue is the obvious presence of tophi, in the absence of peripheral joint synovitis. Was gout also likely to explain the severe hip pain? There are reports of gouty arthritis affecting the hip2–4 as well as case reports of tophaceous deposits in the hip.5 However, the progressively painful right hip and knee with an enlarging mass at the inguinal region was not characteristic of tophaceous deposition, which tends to be more insidious and is usually painless. This definitely warrants consideration of other diagnostic possibilities such as infection or malignancy. Certain ‘warning signs’ (Table 1) should alert the clinician to a potentially serious condition, such as this patient's progressive and severe persistent pain accompanied by significant weight loss.

Table 1.  Warning signs of a potentially serious rheumatic disease6,7
Persistent, progressive pain, not alleviated by rest
Pain intensifies at night and often awakens the patient from sleep
Constitutional/systemic manifestations e.g. fever, weight loss, etc
Neurologic symptoms e.g. saddle anesthesia
Nerve pains, vascular pains, bone pains
Clinical and laboratory features:
 Age > 50
 Previous history of cancer
 Pain longer than 6 weeks
 Markedly elevated erythrocyte sedimentation rate (ESR)
 Unexplained anemia

Clinical data

Hemoglobin was 108 g/L, white blood cell (WBC) 7.4 × 109/L, erythrocyte sedimentation rate (ESR) 41 mm/h, creatinine 1.9 mg/dL (normal 0.8–1.2), sodium 134 mmol/L (136–145), potassium 5.1 mmol/L (3.5–5.0), alkaline phosphatase 80.2 mg/dL (40–129), serum lactic dehydrogenase (LDH) 246 mg/dL (100–190), prostate specific antigen (PSA) 0.53 ng/mL (0–4.0); urinalysis was normal. A radiograph showed a soft tissue density at the medial aspect of the left proximal thigh with no calcifications or evidence of bone or joint involvement (Fig. 1).

image

Figure 1. Right hip X-ray showing soft tissue density at the medial aspect of the left proximal thigh.

Download figure to PowerPoint

Discussion

With a non-diagnostic radiographic finding, the clinico-radiologic issue is the need to perform the more diagnostic but potentially risky imaging procedure of magnetic resonance imaging (MRI) in a patient with renal insufficiency. Literature reports of nephrogenic systemic fibrosis occurring after exposure to a gadolinium-based contrast agent, particularly among patients with reduced renal function,8 recently prompted the American College of Radiology to release MRI safety guidelines to address this growing concern.9 Alternatively, the clinician may opt to perform diagnostic ultrasound, or forego imaging and proceed with a biopsy (with or without ultrasound or CT guidance).

Clinical data

Following hydration, a repeat serum creatinine improved to 1.2 mg/dL, supporting the possibility of acute renal or prerenal cause of the azotemia. We proceeded to perform a contrast MRI of the right hip which disclosed a large enhancing focus at the right inguinal region and proximal medial thigh muscle layers with fairly defined borders from the level of the femoral neck to approximately 10 cm inferiorly, and involving the external obturator and adductor muscle groups. There was another small enhancing focus noted antero-inferiorly in the vastus medialis muscle, which may be an extension of the primary lesion. The large proximal thigh lesion produced slight compression and lateral displacement of the adjacent proximal femoral artery and vein. These findings were suggestive of a sarcomatous tumour (Fig. 2).

image

Figure 2. Right hip magnetic resonance imaging showing an enhancing focus approximately 10 cm in size in the right inguinal region and proximal medial thigh, with compression and lateral displacement of the adjacent femoral artery and vein. Another small enhancing focus was also seen antero-inferiorly in the vastus medialis muscle.

Download figure to PowerPoint

The patient was referred to orthopedics and operative findings disclosed an encapsulated large firm tumoral mass adherent to the proximal femur and extending to the hip joint. Pathologic findings revealed malignant cells and final histopathology confirmed a malignant neoplasm composed of infiltrating cells arranged in an alveolar architecture with intervening thick fibrocollagenous stroma (Fig. 3). Although a malignancy such as rhabdomyosarcoma was initially considered, further immunostaining was consistently positive for cytokeratin and vimentin, which was compatible with a synovial sarcoma. The patient refused to undergo chemotherapy and has been started on radiation therapy.

image

Figure 3. Hematoxylin and eosin stain of the right adductor muscle tumor shows infiltrating cells arranged in an alveolar architecture with intervening thick fibrocollagenous stroma. Immunohistochemical stains were positive for cytokeratin and vimentin.

Download figure to PowerPoint

Discussion

Synovial sarcoma is the fourth most commonly occurring sarcoma, constituting 8–10% of all sarcomas. It can occur in almost equal frequency among men and women in the third to fifth decade of life, but it may also occur in children,10 and is frequently misdiagnosed as a benign condition because of its slow growth and well-defined appearance.11,12 It usually affects the extremities and is found within 5 cm of a joint, with the knee as the most common site of involvement. The name is actually a misnomer since only 10% of cases are intra-articular.

Clinical features are non-specific and the mass is typically slow-growing and painless in most cases. Symptoms depend on the site of involvement and are usually related to a mass effect on the adjacent structures. The patient's severe pain was likely due to hip joint involvement as well as pressure on adjacent nerve structures. Occasionally, synovial sarcoma can present aggressively with metastatic spread to the lymph nodes, bone, bone marrow and lungs.

Complete wide surgical excision is the treatment of choice. This is commonly followed (or preceded, in cases of very large tumours) by local irradiation. For systemic control of the cancer, adjuvant chemotherapy with several combinations has been studied but survival among these patients remains poor. Recurrence within 2 years of initial treatment is common. Overall survival rates are 36–76% at 5 years and 20–63% at 10 years. Synovial sarcoma of the head and neck region generally has a more favourable prognosis with a 5-year survival rate of 47–82%.13 The apparent dismal response to chemotherapy is largely attributed to the fact that soft tissue sarcomas in general do not respond to chemotherapy, although there have been reports stating that synovial sarcoma is more chemo-sensitive than the other subtypes.14 One of the combination chemotherapeutic agents under study is ifosfamide plus doxorubicin which was found to be superior to doxorubicin alone.15 Other chemotherapeutic regimens utilized vincristine, dactinomycin, doxorubicin and cyclophosphamide on patients less than 21 years old. However, the results were not as promising.16

Although synovial sarcoma is uncommon, prompt recognition is of utmost importance so that appropriate management is immediately instituted. Delay in the diagnosis and subsequent treatment could result in permanent disability or worse, death. Doctor delay and patient delay are two of the detrimental factors in initial management, thus we encourage programs for public awareness and continued medical education for general practitioners, orthopedic surgeons, rheumatologists and radiologists be utilized to effect better outcome for these patients.17

SUMMARY

  1. Top of page
  2. Abstract
  3. CASE PRESENTATION
  4. SUMMARY
  5. ACKNOWLEDGMENT
  6. REFERENCES

This case illustrates the presentation of a rare tumour overlying a common rheumatic condition such as tophaceous gout. Issues were discussed as they presented throughout the clinical problem-solving process: some pitfalls in physical diagnosis; need to recognize warning signs of potentially serious disorders; and decisions based on benefit : risk evaluation of imaging procedures (Table 2). An overview of the features and management of synovial sarcoma has been presented.

Table 2.  Key learning points
• It is important to examine the hip in any patient presenting with knee pain. Knee pain in a seemingly normal knee may come from a primary hip pathology.
• Recognition of warning signs of a serious rheumatic disease may be more important than making an actual diagnosis.
• Clinical decisions must be based on the entire patient including the presence of co-morbidities and patient preferences.
• Atypical presentation of a typical disease may signal a complication or another disease entity.

ACKNOWLEDGMENT

  1. Top of page
  2. Abstract
  3. CASE PRESENTATION
  4. SUMMARY
  5. ACKNOWLEDGMENT
  6. REFERENCES

We wish to thank our colleagues – Dr Alita Santos (Pathology), Dr Danilo Lagamayo (Radiology), and Dr Raymond Silverio Barba (Orthopedic Surgery) – for their valuable input in the preparation of this manuscript.

REFERENCES

  1. Top of page
  2. Abstract
  3. CASE PRESENTATION
  4. SUMMARY
  5. ACKNOWLEDGMENT
  6. REFERENCES
  • 1
    Zhang W, Doherty M, Bardin T, et al . (2006) EULAR evidence based recommendations for gout. Part II: Management. Report of a task force of the EULAR Standing Committee for International Clinical Studies Including Therapeutics (ESCISIT). Ann Rheum Dis 65, 131224.
  • 2
    Wissinger HA (1963) Gouty arthritis of the hip joints: report of an unusual case. J Bone Joint Surg Am 45, 7857.
  • 3
    Bates TA (2006) Pathologic fracture of the hip due to severe gouty arthritis. J Rheumatol 33, 188990.
  • 4
    Parhami N, Feng H (1993) Gout in the hip joint. Arthritis Rheum 36, 1026.
  • 5
    Lagier R (1990) Osteoarthritis of hip associated with microscopic gouty tophi. Skeletal Radiol 19, 6972.
  • 6
    Siemionow K, McLain R (2006) When back pain is not benign: a concise guide to differential diagnosis. The characteristic signs and symptoms of the most common serious causes of unremitting back pain. Postgrad Med 119, 629.
  • 7
    Navarra SV (2007) Applied Rheumatology Made Simple (ARMS) Project syllabus (2e) 2007, pp. 4041. Arthritis Care and Research Foundation of the Philippines, Inc., Manila, Philippines.
  • 8
    Thomsen H (2006) Nephrogenic systemic fibrosis: a serious late adverse reaction to gadodiamide. Eur Radiol 16, 261921.
  • 9
    Kanal E, Barkovich A, Bell C, et al . (2007) ACR guidance document for safe MR practices: 2007. AJR 188, 127.
  • 10
    Andrassy RJ, Okcu MF, Despa S, Raney FB (2001) Synovial sarcoma in children: surgical lessons from a single institution and review of the literature. J Am Coll Surg 21, 30513.
  • 11
    Murphey MD, Gibson MS, Jennings BT, et al . (2006) From the archives of the AFIP: imaging of synovial sarcoma with radiologic-pathologic correlation. Radiographics 26, 15436.
  • 12
    Nakajima H, Matsushita K, Shimizu H, et al . (1997) Synovial sarcoma of the hand. Skeletal Radiol 26, 6746.
  • 13
    Duh MJ (2007) Synovial sarcoma. In. LundbergG (ed.) eMedicine, available at http://emedicine.medscape.com/article/396425-overview.
  • 14
    Italiano A, Penel N, Robin Y, et al . (2008) Neo/adjuvant chemotherapy does not improve outcome in resected primary synovial sarcoma: a study of the French Sarcoma Group, Ann Oncol, Advance Access published on December 16, 2008; doi:10.1093/annonc/mdn678.
  • 15
    Edmondson J, Ryan L, Falkson C, Hicks D, Blum R (2003) Phase II study of ifosfamide + doxorubicin in patients with advanced synovial sarcomas (E1973): a trial of Eastern Cooperative Oncology Group. Sarcoma 7, 911.
  • 16
    Pappo A, Fontanesi J, Luo X (1994) Synovial sarcoma in children and adolescents: the St. Jude Children's Research Hospital experience. J Clin Oncol 12, 23606.
  • 17
    Chotel E, Unnithan A, Chandrasekar C, Parot R, Jeys L, Grimer R (2008) Variability of the presentation of synovial sarcoma in children. A plea for greater awareness. J Bone Joint Surg 90B, 10906.