Ross Clark Specialist Registrar Department of Urology Ayr Hospital Dalmellington Road Ayr KA6 6DX
Laura Johnstone Senior House Officer Department of Urology Ayr Hospital Dalmellington Road Ayr KA6 6DX
Graham W Hollins Consultant Urological Surgeon Department of Urology Ayr Hospital Dalmellington Road Ayr KA6 6DX
Case
reports:
Prostate
cancer is an increasingly common malignancy with a well recognised propensity to
metastasise to bone. Basal skull metastases are less common and it is unusual to
see cranial nerve lesions in isolation.
We
describe 2 interesting cases manifesting with ophthalmoplegia secondary to
sphenoid metastases. We would
suggest that metastatic malignancy should always be considered in the
differential diagnosis and prostate cancer excluded.
Case
1:
A
66 year old man initially presented with a history of persistent double vision
and was referred to the Ophthalmology department for further evaluation. A left sixth cranial nerve palsy was confirmed and led to an
MRI scan, which was reported as normal. Progression
of symptoms and the development of bilateral CN VI palsies led to a dedicated
MRI of cavernous sinuses and the sphenoidal ridge. This showed changes in
keeping with possible multiple sclerosis and a neurological opinion was
requested. M.S was excluded and it was thought that the finding were more
consistent with small vessel arterial disease.
Subsequently
bilateral median rectus botulinum toxin injections were performed with some
benefit and corrective surgery was considered.
14 months from presentation the patient developed progressive clinical
signs suggesting involvement of cranial nerves II, III, IV. VI, VII and VIII
with loss of vision, progressive ophthalmoplegia, facial nerve palsy and
sensorineural hearing loss.
An
ENT opinion was requested and a CT at this point showed extensive destruction of
the sphenoid bone, and obliteration of the cavernous sinus on both sides.
Subsequent MRI confirmed these findings with, in addition, extension into the
petrous part of the right temporal bone. This was thought to represent Paget’s
disease or fibrodysplasia with metastatic and primary malignancy felt to be less
likely. Prostate cancer was not
considered at this point.
Two
months later he was admitted with shortness of breath, back pain and weight loss
and anorexia. A chest X-ray showed
a right pleural effusion and osteosclerotic changes in the spine. Alkaline phosphatase was raised at 820 U/L and a bone scan
was arranged. This confirmed extensive changes consistent with widespread
metastatic disease. PSA was measured at 1768µg/L.
Urological
referral and assessment revealed a two year history of lower urinary tract
symptoms, and rectal examination revealed a T4 carcinoma of prostate. Endocrine ablative therapy with maximum androgen blockade was
commenced in the form of Bicalutamide and Goserelin.
This
treatment offered good palliation of his symptoms with some improvement of his
visual and hearing deficits, and marked improvement of his back pain and overall
well-being. His PSA dropped quickly
and remained well controlled for over a year before increasing to over 20µg/l
and other treatment options were considered, although the patient remained well.
Case
2:
A
58 year old presented with a two year history of generalised muscle aches and
pain, which was initially diagnosed as polymyalgia rheumatica and treated with
steroids. Having complained of some lower urinary tract symptoms his GP
measured his PSA which was highly abnormal at 1314µg/L.
He was referred to urology and rectal examination revealed findings
consistent with T4 carcinoma of prostate.
MRI
confirmed locally advanced prostate cancer with bony metastases throughout the
lumbar spine, pelvis and both hips. Bone
scan revealed widespread metastatic disease with further vertebral and rib
lesions, but no evidence of any skull abnormalities.
The patient was commenced on MAB in the form of bicalutamide and
goserelin and his PSA dropped to a nadir of 2.6µg/l.
He
remained well for 12 months before presenting acutely to the physicians with
severe right-sided headache and
diplopia of six weeks duration. He was noted to have ophthalmoplegia on the
right side. PSA on admission was 2.9µg/l.
He was commenced on dexamethasone
with some response and an inpatient CT scan (fig. 1) was carried out. This was
initially reported as normal although subsequent urological review suggested the
possibility of an abnormality of the right sphenoid sinus. Subsequent MRI scan
confirmed a lesion in the region of the right sphenoidal sinus with extension
into the right cavernous sinus consistent with a metastatic deposit.
Sclerotic features of the deposit on further review of the CT meant that
a prostatic primary was extremely likely.
The
patient was referred to the Uro-oncology team and received radiotherapy with
45Gy delivered in 25 fractions. Over the subsequent weeks his headache improved
and diplopia largely resolved. 3
months down the line from the radiotherapy he reported his vision as perfect.
Discussion:
Prostate
cancer is now the most common cancer in males in the UK, with almost 32,000
cases diagnosed every year, representing 23% of all male cancers 1.
Cases are usually diagnosed following presentation with lower urinary tract
symptoms, as a consequence of screening or sadly, and still too commonly, with
bony metastatic disease.
Most
commonly prostate carcinoma metastasises to the axial skeleton and disease
involving the skull and, more specifically, the sphenoid bone is rare 2.
In patients with intracranial disease, however, the sphenoid bone
is the most commonly affected 3. The
radiological features can be subtle and all members of the team must carry a
high index of suspicion.
In
hormone naďve disease, metastatic prostate cancer can be effectively palliated
and the clinical manifestations of such metastases (e.g. bone pain, pathological
fractures and ureteric obstruction) can be prevented or curtailed with androgen
ablative therapy 4. Further palliation may be achieved in
hormone-resistant disease with other treatment modalities such as radiotherapy
or chemotherapy and the symptoms of advanced disease can be controlled, albeit
with limited long term prognosis.
These
cases highlight two unusual manifestations and we would advise that the
possibility of metastatic carcinoma of prostate be borne in mind in men over the
age of 40 years, presenting with such symptoms. Appropriate systemic enquiry and
rectal examination should be considered and PSA
should be checked.
Prostate cancer may
cause unusual symptoms and should always be considered in appropriate age
groups.
References:
1.
Cancer research UK website - Office for National Statistics, Cancer
Statistics registrations: Registrations of cancer diagnosed in 2002, England.
Series MB1 no.33. 2005, National Statistic
2.
Mickel, RA., Zimmerman MC. The sphenoid sinus – A site for metastasis. Otolaryngology – Head and Neck Surgery. Vol 102(6) (pp 709-716), 1990.
3.
Franco E., Gil-Neciga E., Espinosa R., Ruiz-Mateos R., Ollero M.
Sphenoid metastasis mimicking a meningioma as the initial feature of
adenocarcinoma of the prostate. Revista de
Neurologia. Vol. 29(9)(pp 929-932), 1999.
Medical Research Council Prostate Cancer Working Party Investigators Group. Immediate versus deferred treatment for advanced prostatic cancer: initial results of the Medical Research Council trial. Br J Urol. 1997;79:235–246.