Ewing’s
sarcoma is a rare (6% of malignant tumours) malignant neoplasm, most common
in childhood and adolescence. The average age of patients with this tumour
is lower than for any other primary malignant tumour of bone. While any
bone of the axial or appendicular skeleton can be affected, it has rarely
been reported in the bones of hands and feet.1 The characteristic radiological
findings include “onion skin” and moth-eaten appearance of
the lesion. Ewing’s sarcoma may occur entirely in soft tissue. The
differential diagnosis includes osteosarcoma, osteomyelitis, eosinophilic
granuloma and extranodal lymphoma. Histologically, it consists of sheets
of round cells separated by bands of stroma. Metastases are — common
to lungs and other bones. Treatment consists of local surgery, radiotherapy
and adjuvant chemotherapy. Ewing’s sarcoma survival is highly dependent
on the initial presentation of the disease. Approximately 80% of patients
present with localized disease, whereas 20% present with metastatic disease,
most often to the lungs, bone, and bone marrow. The overall survival rate
in patients with Ewing’s sarcoma is 60%; however, for patients with
localized disease, it approaches 70%. Patients with metastatic disease
have less than 25% long-term survival rate.2
We are reporting an unusual case of Ewing’s sarcoma arising from
the metatarsal in a 20 year old male. The unusual features are both the
site as well as the age of the patient. |
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CASE
REPORT
A 20 year old boy presented to us with a gradually increasing swelling
on the dorsum of the right foot, over a period of one
year. There was no history of trauma at the onset. There was no history
of discharging sinuses from the swelling. The patient complained of dull
aching pain at the site. The patient had no constitutional symptoms. There
was no history suggestive of Koch’s or significant contact. The radiographs
of the foot revealed no abnormality and the ESR was 40 mm at one hour.
On the clinico-radiological and haematological suspicion of Koch’s,
an open biopsy was performed. The histopathology report was inconclusive.
The patient was started on anti-tubercular drugs and was advised regular
follow-up. However, he developed a recurrent swelling a month later and
was readmitted for investigations. |
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EXAMINATION
On examination, the swelling was 5 x 5 cms in size, situated over the
fourth metatarsal. There were no dilated veins over the swelling and skin
over swelling was normal. The scar of the previous surgery had healed
by primary intention. There was minimal local warmth and the swelling
had ill-defined margins and was cystic in consistency (Fig. 1). Range of
motion of the ankle and other joints of the foot were normal. There was
no inguinal lymphadenopathy. At this stage, the working diagnosis was
osteomyelitis. |
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INVESTIGATIONS
ON SECOND ADMISSION
Blood investigations revealed the following:
Erythrocyte sedimentation rate : 76 mm at 1 hour
Total Leucocyte count : 10,400
Polymorphs : 49%
Lymphocytes : 51%
Other investigations, including serum alkaline phosphatase were within
normal limits. |
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Fig. 1 : Clinical photograph of patient’s foot
showing the swelling (on 2nd admission) |
Fig. 2 : AP and Lat radiographs of foot, showing
sclerosis of fourth metatarsal shaft
(on 2nd admission) 3 and 4). BIOPSY |
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Fig. 3 : CT scan of foot showing soft tissue
swelling and fourth metatarsal sclerosis |
Fig. 4 : CT scan of foot showing soft tissue
swelling and fourth metatarsal sclerosis |
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RADIOLOGICAL
INVESTIGATIONS
• Plain radiographs
Soft tissue swelling with doubtful erosion in head of fourth metatarsal
and sclerosis of shaft of metatarsal (Fig. 2).
• CT scan of foot
Soft tissue swelling involving distal portion of foot with sclerosis of
head of fourth metatarsal with mild irregularity of cortical margin, suggestive
of infective aetiology (Figs. 3 and 4).
• Bone scintigraphy
Abnormal tracer uptake in right foot, extending upto ankle joint and tarsal
region. Also, increased uptake seen in upper third right tibia, possibly
suggestive of metastases.
• HRCT thorax
Right hilar lymphadenopathy with ground glass appearance of lung parenchyma,
suggestive of metastases. |
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BIOPSY
An open biopsy was performed for the second time. The material had the
appearance of granulation tissue. The sample was subjected to histopathological
examination by two independent pathologists. On this occasion, both the
reports were suggestive of Ewing’s sarcoma of the foot. |
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TREATMENT
In view of the systemic metastases, the patient was started on systemic
chemotherapy. Patient is presently still undergoing chemotherpay, and
is under observation. Tumour has shown regression in size. |
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DISCUSSION
Ewing’s sarcoma of the metatarsal bone is a very rare tumour. Shirley
et al3 reported an incidence of one to four per cent of all Ewing’s
sarcomas. Sancrassagra4 reviewed the largest series of 433 cases of Ewing’s
sarcoma, in which two were
found involving the metatarsal bone. Radiographic appearances can resemble
osteomyelitis, osteogenic sarcoma and metastatic deposits. These were
reported by Vohra5 and observed in our patient as well. Despite the short
tubular bones being a very rare site, it is suggested that with such a
clinical and radiographic presentation, Ewing’s sarcoma should
also be considered in the differential diagnosis. Moreover, all such cases
should be assessed with a high index of suspicion as to the possibility
of the diagnosis being that of a malignant tumour, in order to ensure
timely treatment. |
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ACKNOWLEDGEMENTS
The authors are most grateful to the Dean of BYL Nair Charitable Hospital
for granting permission to publish this clinical material. |
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REFERENCES
1. Leeson MC, Smigh MJ. Ewing’s sarcoma of the foot. Foot Ankle
1989; 10 : 147-51.
2. Toretsky JA. Ewing’s sarcoma and primitive neuroectodermal tumours.
Emedicine.com 2002; Topic 2589.
3. Shirley SK, Askin FB, Gilulal LA, et al. Ewing’s sarcoma in bones
of the hands and feet: A clinico-pathological study and review of literature.
J Clin Oncol 1985; 3 : 686-97.
4. Sancrassagra FA. Ewing’s sarcoma of metatarsal bone. Ceylon Med
J 1973; 18 : 58-61.
5. Vohra VG. Roentgen manifestations in Ewing’s sarcoma: A study
of 156 cases. Cancer 1967; 20 : 727-33. |
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MANAGING
PULMONARY EMBOLISM
Once pulmonary embolism is suspected diagnostic and therapeutic
procedures are highly dependent on the clinical
presentation of the patient, the local resources, and the expertise
of the doctor treating the patient. Many algorithms have been
established to prevent underdiagnosing and over-diagnosing the
disease as both carry a substantial risk of fatality. Unfortunately
a universally accepted approach to the management of pulmonary
embolism is still missing.
Four major issues in pulmonary embolism management deserve particular
attention: D-dimer testing, computed tomography pulmonary angiography,
thrombolytic treatment, and low molecular weight heparins.
Plasma D-dimers have an excellent negative predictive value. Spiral
computed tomography has advanced in many institutions to the first
line imaging technique to rule in pulmonary embolism.
Intuitively it seems to make sense to apply thrombolytic treatment
in patients with massive pulmonary embolism. Low molecular weight
heparins have revolutionised the early treatment of haemodynamically
stable patients with
pulmonary embolism.
BMJ, 2003; 326 : 1341-2. |
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