Grand Rounds Vol 9 pages 59–62
Speciality: Specialities Oncology, Orthopaedic surgery
Article Type: Case Report
DOI: 10.1102/1470-5206.2009.0009
ß 2009 e-MED Ltd
A rare case of bone metastases from
adenocarcinoma of the parotid gland
J. Conibeara, C. Jayadevb, A. Sharmac, P. Achanb and S. Amena
a
Department of Oncology, St. Bartholomew’s Hospital, London, UK; bDepartment of Trauma
& Orthopaedics, The Royal London Hospital, London, UK; cDepartment of Medical Oncology,
St. Bartholomew’s Hospital, London, UK
Corresponding address: A. Sharma, Chase Farm Hospital, The Ridgeway, Enfield,
Middlesex, EN2 8JL, UK.
Email: [email protected]
Date accepted for publication 10 August 2009
Abstract
A woman with known adenocarcinoma of the right parotid gland presented with bony metastasis
in her left proximal femur. This was histologically confirmed and the patient underwent
prophylactic intramedullary nail and hip screw fixation of her left proximal femur. This represents
the first report of adenocarcinoma of parotid origin metastasising to a long bone in an adult.
Keywords
Adenocarcinoma parotid; metastasis; proximal femur; prophylactic intramedullary nail; hip screw
fixation.
Introduction
Tumours of the salivary glands are rare and represent less than 1% of all cancers and
approximately 5% of head and neck cancers. In the United Kingdom, 550 new cases are diagnosed
each year[1]. The parotid glands are the largest salivary glands and are the most common site of
salivary gland tumours, accounting for 75% of the total. The majority of parotid gland tumours
are benign; around 25% are malignant. Many types of parotid malignancies exist, and most arise
from the epithelial elements of the gland. The most common malignant parotid neoplasm in
adults is mucoepidermoid carcinoma, which represents almost one-third of such tumours. Other
parotid malignancies include adenoid cystic carcinoma, malignant mixed tumours, acinic cell
carcinoma and adenocarcinoma.
In this report we discuss the case of a 64-year-old woman with known adenocarcinoma of the
right parotid gland. In June 2007, the patient was found to have a bony metastasis in her left
proximal femur. The patient underwent prophylactic fixation of the left femur to prevent
impending pathological fracture.
Case report
In 2004, the patient originally presented with a history of itching and fullness in her right ear. She
was diagnosed with adenocarcinoma of the parotid gland and underwent radical surgery at
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Fig. 1. Plain radiograph of left proximal femur showing a lytic lesion in the inter-trochanteric region.
another institute in January 2005 and again in June 2005. Due to disease progression, the patient
was referred to a tertiary referral centre for reassessment. Review of the patient’s histopathology
confirmed Grade 2 adenocarcinoma of the right parotid gland. Magnetic resonance imaging (MRI)
and computed tomography (CT) imaging at the time showed intracranial extension of the disease
and the decision of the multidisciplinary team was that the tumour was no longer operable. The
patient was subsequently referred to the Clinical Oncology Department in St. Bartholomew’s
Hospital for consideration of radiotherapy. In October 2005, the patient completed radical
radiotherapy for her parotid adenocarcinoma but then developed thecal nerve root compression
due to bony metastases in the lumbar-sacral area. The patient received a course of palliative
radiotherapy to her lumbar-sacral region which helped relieve her symptoms.
A staging CT scan of the patient in December 2006 revealed extensive lung metastases. By April
2007, the patient had completed six cycles of palliative chemotherapy but then needed further
palliative radiotherapy to her thoracic spine in May 2007 when she was found to have thoracic
bone metastases.
On the 21 June 2007 the patient was admitted to St. Bartholomew’s Hospital with a 1-week
history of pain radiating down her left leg and difficulty mobilising. The patient reported
weakness of her left leg and was found to have reduced hip flexion due to pain. Given the
background of spinal metastases, an urgent MRI scan was conducted to exclude cord
compression. This showed no evidence of cord compromise and stable disease in the spine. A
plain radiograph (Fig. 1) of the patient’s left hip revealed a lytic lesion in the proximal femur.
Given the patient’s primary disease and the infrequency of long bone metastases by parotid
adenocarcinoma, this lesion could not be assumed to be a metastatic deposit without histological
confirmation.
A CT-guided biopsy of the lesion was therefore organised. Histological analysis of the biopsy
specimen confirmed adenocarcinoma in the peritrochonteric region of the proximal left femur.
Because of the high risk of impending pathological fracture based on Mirels’ scoring system[2],
the patient underwent prophylactic intramedullary nail and hip screw fixation of the left femur
(Fig. 2). The patient had an uneventful post-operative recovery phase and following extensive
physiotherapy was discharged home to return on an outpatient basis for adjuvant radiotherapy to
the left femur.
Bone metastases from adenocarcinoma of the parotid gland
61
Fig. 2. Prophylactic intramedullary hip screw fixation of left femur.
Discussion
Distant skeletal metastases from primary malignant parotid tumours are rare[3]. There are
documented cases of bony metastasis in the context of adenoid cystic carcinoma[4,5], malignant
mixed tumour[6], acinic cell carcinoma[7] and even the ‘benign’ pleomorphic adenoma[8], but most
of these were to the axial skeleton. Adenocarcinoma of the parotid gland is an aggressive lesion
with both lymphatic and distant metastatic potential and one-third of patients have such
metastases at the time of initial diagnosis. However, metastasis to bone and in particular to long
bones is extremely rare with very few cases documented in the literature. A femoral metastasis
from a non-parotid buccal salivary gland adenocarcinoma has been a described in a child[9] and a
humeral metastasis from a parotid adenocarcinoma has been described in a canine[10].
This case report of parotid adenocarcinoma with histologically confirmed proximal femoral
metastasis treated by prophylactic fixation is the first of its kind in the English literature. Indeed,
it represents the first and only report of adenocarcinoma of parotid gland origin metastasising to
a long bone in a human adult.
Teaching point
Distant metastases from primary malignant parotid gland tumours are rare. This case represents
the only report of adenocarcinoma of parotid origin metastasising to a long bone. Recognition of
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such data is important for appropriate and early management of patients, and to develop
understanding of the disease.
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