Keywords
Carcinoma buccal mucosa - choroidal metastasis - distant metastasis - secondaries
in eyes
Introduction
Secondaries are most common ocular neoplasms, and the choroid, being a highly vascular
layer, is the most common part of eye for metastasis.[1] Metastasis outnumbers the primary ocular neoplasms, for example, retinoblastoma
and malignant melanoma. The common sources of ocular metastasis are primaries from
the breasts (38%–40%), lungs (20%–29%), gastrointestinal and genitourinary malignancies.
Choroidal melanoma and hemangioma are important differential diagnoses which mimic
this condition. Ocular metastasis from a primary head and neck cancer is a rarity.
The common distant sites involved by head and neck cancer are lungs, mediastinal nodes,
bones, and liver.[1] Choroidal deposits from a carcinoma of buccal mucosa are extremely rare. We report
a case of carcinoma buccal mucosa metastasizing to the choroid. The purpose of this
report is to draw attention toward a rare and unique presentation of head and neck
cancer, where choroidal metastasis was seen without evidence of any other distant
metastasis in a patient of early oral cavity carcinoma.
Case Report
A 62-year-old male diagnosed with carcinoma of the left buccal mucosa in September
2012. He was operated upon (wide local excision of left buccal mucosa with left hemimandibulectomy
and modified neck dissection type II) in September 2012. Histopathology report suggested
squamous cell carcinoma of size 2.5 cm × 2.0 cm × 1.7 cm. All 31 lymph nodes dissected
from left level I to V were free (0/31) of metastasis. No perineural or lymphovascular
invasion was seen. Overlying skin was free. Depth of invasion was 0.7 cm. All the
margins and cut end of bone were free. It was pathological stage pT2N0Mx. The metastatic
workup at the time of surgery was negative for any distant metastasis. The patient
was advised adjuvant radiotherapy (60 Gray in 30 fractions) from October 20, 2012
on a 6 MV linear accelerator with a two field wedge plan (Antero Posterior and Lateral
field). During treatment (after 28 Gray/14 fractions), the patient presented with
painless, gradually progressive diminution of vision of the left eye. A thorough ophthalmological
examination was done which included slit lamp examination, ultrasonography (USG) of
eyes, and magnetic resonance imaging (MRI) of both eyes and brain. Biopsy was not
possible from the choroidal mass. The USG scan [Figure 1] revealed choroidal lesion suggestive of secondaries in the left eye. MRI brain and
both eyes [Figure 2] and [Figure 3] showed the presence of altered signal intensity in the posterior chamber of the
left eye which was hyperintense in T1-weighted sequence and hypointense on T2-weighted
sequence. A solitary deposit in the left choroid involving 80% of the globe with secondary
retinal detachment was seen. There was no other choroidal or brain metastasis. Positron
emission tomography-computed tomography (PET-CT) evaluation showed metastatic disease
in the left choroid, with no other involved site elsewhere in the body.
Figure 1: Ultrasonography scan of the left eye showing mass in choroid
Figure 2: Magnetic resonance imaging scan of the left eye
Figure 3: Magnetic resonance imaging scan of both eyes and brain
The radiotherapy treatment for the carcinoma buccal mucosa was completed by the time
the metastatic disease was confirmed. In view of stage IV disease, the patient was
advised chemotherapy, i.e., paclitaxel and carboplatin. He received three cycles and
had no symptomatic improvement. The patient was then lost to follow-up.
Discussion
Ocular neoplasm may be a primary or secondary. The secondaries are far more common
than the primary neoplasm.[2] The choroid is the highly vascular layer of the eye and thus the most common site
for homing of the malignant cells although the retina and ciliary body can also be
involved. Even in the malignancies where ocular metastasis is common such as carcinoma
breast, carcinoma lung, and carcinoma of gastrointestinal tract, the first sites of
metastasis are the lungs, brain, bones, and liver before the eyes being affected.
Development of ocular secondary without involvement of all these sites is rare, and
development of ocular metastasis without development of brain metastasis is even rarer.[2]
Unilateral choroidal metastasis is more common than bilateral metastasis.[3] Some studies have indicated that metastatic disease is more common in the left eye
as the left common carotid ascends directly off the aorta; tumor cells from the circulation
could have a more direct path to left orbit. Diagnosing the disease is often challenging.
Retinal detachment, intravitreal, and subretinal hemorrhage are the common complications
of choroidal metastasis. Retinal detachment gives rise to visual loss which is very
common in these cases.[4]
Ultrasonography shows diffuse choroidal thickening with high or medium amplitude echoes
and may mimic choroidal melanoma which is an important differential diagnosis. USG
can provide an idea about the local extent of the mass but cannot differentiate between
a primary and metastasis.
Clinical profile, MRI, and fludeoxyglucose PET CT can help in differentiating this
condition from the common differential diagnoses, for example, choroidal melanoma
and hemangioma, although none of these investigations are diagnostic. The treatment
options after diagnosis of distant metastasis are very limited and depend mainly upon
the distant site of metastasis. The treatment is mainly palliative with the aim of
symptomatic relief.
Palliative radiotherapy can be delivered for pain or proptosis. It may improve symptoms
in 80% of patients but may or may not restore vision. Chemotherapy for systemic disease
can help to control ocular metastasis. The most active chemotherapeutic agents in
metastatic head and neck cancers are platin, taxanes, 5-fluorouracil, and cetuximab.[5],[6],[7],[8] Palliative surgery comes into play for intractable ocular morbidities such as proptosis
and pain which need urgent intervention. Hormone therapy can help in hormone-sensitive
tumor like carcinoma breast.[9] Patient's performance status, life expectancy, status of the primary tumor, and
possible side effects of the intended treatment determines the line of management.
The overall prognosis for such patients remains poor.[10] However, when the primary disease is under control and eye is the only metastatic
site, as in this case, or in carcinoma breast patients, where overall survival has
improved dramatically in recent times, the search of some novel targeted treatment,
new investigational agents, and advances in radiotherapy techniques may lead to better
quality of life and preservation of ocular function.
Conclusion
Although ocular metastasis is not common in head and neck cancer, any patient having
visual complaints should be thoroughly investigated. In rare instances, it can also
be the first manifestation of an underlying undiagnosed malignancy. Although it is
difficult to cure, early diagnosis can lead to prompt interventions which can lessen
the suffering of the patient and restore or preserve the remaining visual function.
