from the Department of Clinical Radiology, Leeds Teaching
Hospitals, Leeds, United Kingdom.
A 49-year-old woman was referred from her primary-care physician
with a 4-month history of left iliac fossa and groin pain that kept
her awake at night. This required a transcutaneous electrical nerve
stimulation (TENS) machine in addition to oral analgesia. Her
relevant medical history was of carcinoma of the cervix 9 years
previously for which she was treated with a Wertheim's hysterectomy
but no adjuvant radiotherapy. Examination was unremarkable, and all
blood levels, including plasma viscosity, blood count, and bone
chemistry, were normal. A barium enema, pelvic ultrasound, and
small bowel study were normal (not shown). A computed tomographic
(CT) scan of the abdomen and pelvis was normal (not shown).
In view of the normal findings with ongoing severe pain, an
orthopedic opinion was sought. He found minor limitation of
movement of the hip but no associated muscle wasting. The patient's
weight was steady, and she had not experienced night sweats. Hip
radiographs were requested, which demonstrated an ill-defined
lucency in the left femoral neck/head (Figure 1).
The patient was taking steroids for asthma and a magnetic
resonance image (MRI) was requested to exclude avascular necrosis
of the femoral head (Figure 2). This demonstrated a small hip
effusion, high signal on short tau inversion recovery in the
femoral neck, which was consistent with edema and disruption of the
This raised the possibility of metastasis from the previous
carcinoma of the cervix. A full-body bone scintogram was performed
to look for further lesions (Figure 3), which showed a solitary
area of increased tracer uptake in the left femoral neck/head.
A CT-guided bone biopsy was performed to determine the nature of
the lesion. The CT showed a diffuse lesion of mixed lytic and
sclerotic appearance in the left femoral neck (Figure 4). The
biopsy was reported as normal. This was discussed with the
orthopedic surgeon, and as this did not correlate with the
radiological and clinical findings, the patient was recalled for a
second biopsy. This showed features of a diffuse large B cell
lymphoma staged as 1E, an isolated lesion restricted to a single
Primary bone lymphoma
Primary bone lymphoma is defined as a tumor involving a single
focus with unequivocal evidence of lymphoma in the bone lesion.
It is rare, accounting for <1% of all non-Hodgkin's lymphomas
and 5% of all primary bone tumors.
Most cases are of the diffuse large B-cell category.
The age distribution is bimodal with peaks in the second to third
decade, and a second peak in the fifth to sixth decade with women
more commonly affected in the older age group.
There is a wide pattern of bone involvement with the spine forming
the most frequent site of axial lesions, and the femur is the most
common site overall.
In many cases, the diagnosis is delayed because of nonspecific
Chronic dull pain may be the only complaint.
Radiographic findings do not conform to a diagnostic pattern,
but 58% show osteolysis, with soft tissue involvement in 70% of
Periosteal reaction is rare.
The definitive diagnosis is made from biopsy and histology.
Clinical stage follows the Ann Arbor classification, which
determines the extent to which the tumor has metastasized. Grading
is obtained from the tumor histology. The stage of the disease
appears to be the most important prognostic indicator, with an
overall 5-year survival rate of 54%.
The patient's initial presentation had been with left iliac
fossa pain and her initial work-up was aimed at
intra-abdominal/pelvic pathology in view of her medical history.
This led to a significant delay before an orthopedic opinion was
sought. This is very common and highlights the need to always
consider bone pathology as a source of ill-defined pain,
particularly when it disturbs the patient's sleep.
The radiologic findings were nonspecific, but were suggestive of
malignant disease. In particular, the lytic appearance on the
radiograph and the loss of the femoral cortex on the MRI with
the associated effusion were suspicious. Primary bone lymphoma
typically has nonspecific radiologic findings. In cases such as
this, biopsy is essential, after discussion with an orthopedic
surgeon, to establish the diagnosis. If the clinicoradiologic
findings and histology do not match, repeat biopsy is