Squamous cell carcinoma of the temporal bone originating in Paget skull.
CASE REPORT: A 45 year old male farmer presented to the outpatient services of the Department of Otolaryngology, with complaints of hearing loss in his right ear for 2 years. He also complained of a ringing sound from his right ear which was continuous and non pulsatile. The patient had a history of occasional ear discharge in his childhood which had since then subsided. Clinical examination revealed a mass filling the right external auditory canal with no view of the tympanic membrane. The facial nerve was intact and pure tone audiometry revealed a severe mixed hearing loss. Cranial nerve examination revealed no abnormality. The patient had frontal bossing. Examination of the head and neck showed no other swelling or lymphadenopathy. Examination of the other systems revealed no abnormality Histopathological examination of the tissue from the external auditory canal revealed a diagnosis of moderately differentiated squamous cell carcinoma. HPE was done after taking biopsy from growth in the external auditory canal.
Computerized tomography of the skull and the temporal bone showed an irregular expansile lytic lesion in the right external auditory canal, extending to the middle ear and inner ear with destruction of the tympanic membrane, ossicles (Figure 1). The lesion also involved the right petrous temporal bone with destruction of the right carotid canal, right jugular canal and occipital bone near the jugular foramen. The skull bones showed regions of 'cotton wool' (Figure 2). X-rays of the long bones, pelvis and chest revealed no abnormality. Biochemical investigations revealed a grossly elevated serum alkaline phosphatase and a marginally elevated serum calcium level. Urinary hydroxyproline was positive.
A radical mastoidectomy was performed on the patient in an attempt to clear as much of the disease as possible. The tumour was found to fill the external auditory canal, mastoid antrum, middle ear and extending in to the petrous apex. The disease in the external ear, mastoid and the middle ear were removed. Histopathology of the tumour tissue confirmed the diagnosis of moderately differentiated squamous cell carcinoma.
The patient was subsequently discussed in our tumour board meet and completed external beam radiation for the residual disease. Currently the patient is receiving medical therapy for the Paget disease. Patient was put on etidronate 400mg for 6months. But he was lost to follow up after about 6 weeks.
DISCUSSION: Paget disease of the bone first described by Sir James Paget in 1876 is characterised by abnormal bone remodelling. There is an increase in osteoclastic activity within the bone which is followed by a compensatory increase in osteoblastic activity (1, 2). The new bone which has formed is weak and disorganized and is prone for fractures or deformities (1, 2). The etiology remains unknown but both genetic (3) and viral (4) causes have been implicated. The patients are usually asymptomatic and are diagnosed when they present with complications (2). Since it is just a case report we prefer to put it in discussion. However we go by reviewer's decision.
Paget disease can be monostotic or polyostotic depending upon the bones involved (1). Monostotic disease is seen in 15% of the patients where it involves one bone. Polyostotic involvement is seen in the remainder 85% and usually involves the skull, spine and pelvis. Pain is the most common complaint seen in patients with pagetic bone disease (1, 2). Paget disease is associated with certain benign bone conditions like giant cell tumour. Malignant transformation is rare and the development of sarcoma is a dreaded complication (1, 3). The incidence of sarcoma formation is about 0.7%-0.9% in monostotic disease whereas it increases to 5%-10% in polyostotic disease (1). This is probably the first time that Paget disease of the bone with squamous cell carcinoma has been reported.
The diagnosis of Paget disease is usually by radiological and biochemical means (2). Skull radiographs reveal regions of 'cotton wool', thickening of diploic areas and enlargement and sclerosis of the skull bones (2). There is usually a parallel rise in serum alkaline phosphatase and urinary hydroxyproline levels (2). Since Paget disease is a metabolic disorder affecting bones and characterised by constant phase of osteolytic and sclerotic changes it give rise to increased levels of alkaline phosphatase due to rapid demineralization.
Serum calcium and phosphorus however tend be normal in most cases. Malignant transformation in Paget disease is usually diagnosed by CT or MRI scanning along with tissue biopsy (2).
Paget disease of the skull involving the temporal bone is characterised by hearing loss, vertigo and tinnitus (6, 7). The type of hearing loss is variable. The hearing loss is caused by a change in the bone mineral density of the otic capsule. This mechanism explains the characteristic high frequency sensorineural hearing loss with air bone gap.
Earlier studies however indicate that a mixed type of hearing loss is frequently seen in patients with Paget disease. Tinnitus is a common accompanying symptom. The treatment of Paget involves the use of bisphosphonates (2). Pharmacological agents are used to control symptoms caused by the metabolically active Paget disease and to prevent local progression and complications in asymptomatic patients. Zoledronic acid is considered the agent which offers a maximal disease remission. Oral bisphosphonates are generally well tolerated, but may irritate gastrointestinal tract. Long-term bisphosphonate therapy has been linked to a rare problem in which the upper thigh bone cracks, but doesn't usually break completely. Bisphosphonates also may increase the risk of osteonecrosis of the jaw bone.
Malignancies of the temporal bone are rare. Squamous cell carcinoma is the most common malignancy of the temporal bone. The etiology is unknown but ionizing radiation (8), chronic otitis media 9 and aflatoxin exposure have all been implicated. Pain and otorrhea are the commonest complaints 8. There is currently no accepted staging systems available for malignancies of the temporal bone although 2 systems namely the TNM staging by the University of Pittsburgh and the University of Arkansas for Medical Sciences are used. The treatment of choice is still in doubt because of the fewer number of cases and the lack of controls. Surgical options include mastoidectomy, lateral resection and subtotal resection of the temporal bone 10. For early lesions, mastoidectomy can be tried but for extensive tumours subtotal or even total resection of the temporal bone should be considered. Post operative radiation is necessary in patients with regional lymphadenopathy, perineural/neural invasion and positive or close margins. In extensive tumours, piecemeal clearance and post operative radiation can be tried. Treatment of squamous cell Ca of temporal bone depends on stage of the disease. For stage 1 and stage 2, external auditory canal resection with or without mastoidectomy may suffice. For stage 3 and 4 subtotal or total temporal bone resection is advised. Radiotherapy may follow Surgery.
CONCLUSION: Paget disease of the bone is a bone disorder characterised by bone remodelling. Malignant transformation is rare and sarcomas are associated with such a transformation. This is perhaps the first time that Paget disease of the skull is associated with squamous cell carcinoma of the temporal bone. It is not sure if it is just a co-incidence or there is any true correlation. Further studies are required.
(1.) Rosenberg AE. Bones, Joints and Soft Tissue Tumours. In, Kumar V et al (ed). Pathological Basis of Disease, 7th edition. New Delhi, Elsevier Publishers, 2005; 1284-1286 Comment [D11]: Check this reference.
(2.) Favus MJ, Vokes TJ. Paget disease and other dysplasias of bone. In, Kasper DL et al (ed). Harrison's Principles of Internal Medicine, 16th edition. New Delhi, McGraw-Hill, 2005; 2279-2282 Comment [D12]: Check this reference.
(3.) Deyrup AT, Montag AG, Inwards CY, Xu Z, Swee RG, Krishnan Unni K. Sarcomas arising in Paget disease of bone: a clinicopathologic analysis of 70 cases. Arch Pathol Lab Med 2007; 131: 942-6.
(4.) Lucas GJ, Daroszewska A, Ralston SH. Genetics of Paget's disease of bone. J Bone Miner Res 2006; 21 Suppl 2: 31-7.
(5.) Friedrichs WE, Reddy SV, Bruder JM, Cundy T, Cornish J, Singer FR, Roodman GD. Sequence analysis of measles virus nucleocapsid transcripts in patients with Paget's disease. J Bone Miner Res. 2002; 17: 145-51.
(6.) Mackenzie I, Young C, Fraser WD. Tinnitus and Paget's disease of bone. J Laryngol Otol. 2006;120: 899-902.
(7.) Monsell EM. The mechanism of hearing loss in Paget's disease of bone. Laryngoscope. 2004; 114: 598-606.
(8.) Kuhel WI, Hume CR, Selesnick SH: Cancer of the external auditory canal and temporal bone. Otolaryngol clin North Am 1996; 29: 827.
(9.) Arena S, Keen M. Carcinoma of the middle ear and temporal bone. Am J Otol 1998; 9: 351356.
(10.) Breau RL, Dornhoffer JL. Cancer of the ear and temporal bone. In, Myers EN et al (ed). Cancer of the head and neck, 4th edition. Philadelphia, Saunders, 2003; 531-544.
[1.] Somanath B Megalamani
[2.] Ravi D.
[3.] S. Gopalakrishnan
[4.] Deepak Balasubramanian
PARTICULARS OF CONTRIBUTORS:
[1.] Assistant Professor of E.N.T, KIMS, Hubli.
[2.] Associate Professor of E.N.T, MIMS, Mandya.
[3.] Professor and HOD, Department of E.N.T, JIPMER, Pondicherry.
[4.] Senior Resident, Department of E.N.T, JIPMER, Pondicherry.
NAME ADRRESS EMAIL ID OF THE CORRESPONDING AUTHOR:
Dr. Somanath. B. Megalamani, Assistant Professor, Dept. of E.N.T, Karnataka Institute of Medical Sciences, Hubli.
Date of Submission: 11/07/2013.
Date of Peer Review: 11/07/2013.
Date of Acceptance: 15/07/2013.
Date of Publishing: 18/07/2013
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|Title Annotation:||CASE REPORT|
|Author:||Megalamani, Somanath B.; Ravi, D.; Gopalakrishnan, S.; Balasubramanian, Deepak|
|Publication:||Journal of Evolution of Medical and Dental Sciences|
|Article Type:||Clinical report|
|Date:||Jul 22, 2013|
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