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Sphenoid Sinus Mucocoele and Cranial Nerve Palsies in a Patient with a History of Nasopharyngeal Carcinoma: May Mimic Local Recurrence
Clinical Oncology
Clinical Oncology (2001)13:353–355 # The Royal College of Radiologists
Case Report Sphenoid Sinus Mucocoele and Cranial Nerve Palsies in a Patient with a History of Nasopharyngeal Carcinoma: May Mimic Local Recurrence C. S. F. Wong, S. H. Luk, T. W. Leung, K. K. Yuen, W. K. Sze and S. Y. Tung Tuen Mun Hospital, Tuen Mun, Hong Kong Abstract. We report the case history of a patient with a sphenoid sinus mucocoele detected by computed tomography and medical resonance imaging. The patient had a history of nasopharyngeal carcinoma, which was treated by radiotherapy more than 10 years previously. He presented with bilateral twelfth and sixth cranial nerve palsies. Local tumour recurrence was suspected. Further investigations showed that the cranial nerve palsies were caused by radiation damage and the sphenoid sinus mucocoele was an incidental finding. Sphenoid sinus mucocoele is a possible rare late complication of radiotherapy in patients with nasopharyngeal carcinoma. Keywords: Cranial nerve palsies; Late complications; Nasopharyngeal carcinoma; Radiotherapy; Recurrence; Sphenoid sinus mucocoele
Case History A 49-year-old Chinese man was referred to our department in June 1996 because of dysphagia. He had had a diagnosis of nasopharyngeal carcinoma (NPC) made in China in 1977, when he presented with headache and bilateral enlargement of the cervical neck lymph nodes. He was subsequently treated with radical radiotherapy. Details regarding the initial stage, the treatment technique and the radiation dose are unknown. The patient complained of dysphagia since 1990, which was becoming worse during 1996. He was then seen at our department. There was no history of nasal or aural symptoms and there was no significant weight loss. Physical examination showed bilateral twelfth cranial nerve palsies. No abnormal cervical lymph nodes were detected. There was no evidence of recurrence of the nasopharyngeal tumour. The provisional diagnosis was post-irradiation twelfth cranial nerve palsies. However, the patient refused further investigations. We then referred him to a speech therapist and he claimed that the dysphagia subsequently improved subjectively. The patient was lost to follow-up after August 1996, but he reattended in April 1998, complaining of diplopia over the previous few months. Physical examination then revealed bilateral sixth cranial nerve palsies in addition to the twelfth nerve palsies. Telangiectasia and atrophic Correspondence and offprint requests to: C. S. F. Wong, Department of Clinical Oncology, Tuen Mun Hospital, Tsing Chung Koon Road, Tuen Mun, Hong Kong. Fax: +852 24685097.
mucosa were found in the nasopharynx but no recurrence was noted on fibreoptic examination. The cervical lymph nodes were not palpable. In view of the past history of NPC and the finding of new cranial nerve palsies, local recurrence had to be excluded. A contrast computed tomographic (CT) scan of the nasopharynx and base of the skull was performed, which showed an expanded sphenoid sinus filled with homogeneous hyperdense material, leading to the suspicion of an
Fig. 1. Post-contrast CT scan of the brain: expanded sphenoid sinus with hyperdense content. The sinus wall is eroded.
a
b Fig. 2. (a) T1-weighted coronal and (b) T2-weightd sagittal MRI of the brain. The sphenoid sinus is expanded with T1W andT2W hyperintense material. The nasopharynx is clear of any tumour recurrence.
enhancing sphenoid tumour mass (Fig. 1). There was no abnormality in the nasopharynx. A magnetic resonance imaging (MRI) study showed a homogeneous increase in signal intensity in both T1- and T2-weighted images in the sphenoid sinus (Fig. 2). The finding was consistent with the presence of proteinous fluid and a diagnosis of sphenoid mucocoele was made. There was bone remodelling and comprehensive erosion of the sphenoid floor, with lobulated extension of the mass into the nasopharynx and posterior nares. The cavernous sinuses were not involved. No other structural lesion affecting the cranial nerves could be found. There was a generalized patchy increase in bone density over the skull base and facial bone, which was consistent with post-irradiation changes. In order to confirm the diagnosis of mucocoele and to rule out any possible tumour recurrence, biopsy of the sphenoid sinus was performed. Chronic inflammation was revealed, but no malignant cells were seen. No infection was demonstrated within the mucocoele. The cranial nerve palsies persisted after the biopsy.
Discussion Isolated sphenoid sinus mucocoeles are rare. The incidence has been reported to be 1% of all paranasal sinus mucocoeles [1]. The most common clinical symptoms are headache and visual disturbance [2]. An association between this condition and radiotherapy has rarely been reported [3,4]. Porter et al. analysed CT scan findings for the paranasal sinuses before and after radiotherapy for nasopharyngeal carcinoma [5]. They concluded that chronic sinus disease was a common late complication of radiotherapy. In 1991, Rejab et al. reported the occurrence of a sphenoid sinus mucocoele, which was found in a patient who had received radiotherapy for nasopharyngeal carci-
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noma 6 years previously [3]. The authors commented that the cause could have been the occlusion of the sinus ostium by scarred mucosa after radiotherapy. Their patient presented with blurring of vision, which recovered after drainage of the mucocoele. In 1997, Wong et al. also reported an occurrence of sphenoid sinus mucocoele in a patient who had received a course of radiotherapy for nasopharyngeal carcinoma more than 10 years previously [4]. The mucocoele caused compression of the pituitary– hypothalamic region. This patient developed frequent yawning attacks, which improved after drainage of the mucocoele. Our current patient presented with dysphagia of 6 years’ duration, occurring 17 years after radiotherapy. The symptom was attributed to bilateral twelfth cranial nerve palsies. He also developed diplopia 19 years after radiotherapy. Physical examination showed bilateral sixth cranial nerve palsies. King et al. analysed the details of 17 patients who developed twelfth cranial nerve palsy after radiotherapy. Radiation-induced neuropathy was the probable cause in 14; its relationship to tumour recurrence was infrequent (only 11.8%) [6]. Lee et al. reported in 1992 that the incidence of cranial nerve palsies among patients with nasopharyngeal carcinoma treated with radical radiotherapy in Hong Kong was 5% [7]. The latent interval ranged from 0.5 to 11 years. The last four cranial nerves (particularly the twelfth) were most commonly affected, followed by the sixth. The finding of both twelfth and the sixth cranial nerve palsies in our patient was compatible with the results reported by Lee et al. However, the latency of the sixth cranial nerve palsy was unusually long. One has to investigate further the cause of a new cranial nerve palsy in patients with a history of nasopharyngeal carcinoma treated by radiotherapy many years previously. Local recurrence was unlikely in our patient in view of the long time since the radiotherapy (19 years) and the normal nasopharyngeal findings on both CT scanning and MRI. Lee et al. reported in 1999 that only 9% of recurrences occur later than 5 years after radical radiotherapy [8]. Radiation-induced malignancy (e.g. sarcoma) is another possibility. In our patient, the incidental findings of mucocoele was suspected on the CT scan and was delineated well by MRI.
Conclusion Sphenoid sinus mucocoele is a possible late complication of radiotherapy in patients with nasopharyngeal carcinoma. Its presentation in such a setting may sometimes mimic recurrence, especially when it causes compression symptoms. The most common cause for new cranial nerve lesions after radical radiotherapy for NPC is radiationinduced neuropathy, but one also has to rule out local recurrence. CT scanning and MRI are useful tools in making the diagnosis. The biopsy of any lesion detected may be necessary when a diagnosis cannot be confirmed. Drainage of the mucocoele may have to be considered to relieve the symptomatic effects of compression.
References 1. Zizmor J, Noyek A. Cysts and benign tumours of the paranasal sinuses. Semin Roentgenol 1968;3:172–201. 2. Sethi DS, Lau DPC, Chan C. Sphenoid sinus mucocoele presenting with isolated oculomotor nerve palsy. J Laryngol Otol 1997;111:471–3. 3. Rejab E, Said H, Saim L, et al. Sphenoid sinus mucocoele: a possible late complication of radiotherapy to the head and neck. J Laryngol Otol 1991;105:959–60. 4. Wong KYR, Ngan KCR, Sin VC, et al. Sphenoidal sinus mucocoele and yawning after radiation treatment for nasopharyngeal carcinoma. Clin Oncol 1997;9:415–7. 5. Porter MF, Leung SF, Ambrose R, et al. The paranasal sinuses before and after radiotherapy for nasopharyngeal
carcinoma: a computer tomographic study. J Laryngol Otol 1996;110:199–22. 6. King AD, Leung SF, Teo P, et al. Hypoglossal nerve palsy in nasopharyngeal carcinoma. Head Neck 1999;21:614–9. 7. Lee AWM, Law SCK, Ng SH, et al. Retrospective analysis of nasopharyngeal carcinoma treated during 1976–1985: late complications following megavoltage irradiation. Br J Radiol 1992;65:918–28. 8. Lee AWM, Foo W, Law SCK, et al. Recurrent nasopharyngeal carcinoma: the puzzles of long latency. Int J Radiat Oncol Biol Phys 1999;44:149–56.
Received for publication May 2000 Accepted following revision July 2000
Mimicking of Local Recurrence of Nasopharyngeal Carcinoma
355
Clinical Oncology (2001)13:353–355 # The Royal College of Radiologists
Case Report Sphenoid Sinus Mucocoele and Cranial Nerve Palsies in a Patient with a History of Nasopharyngeal Carcinoma: May Mimic Local Recurrence C. S. F. Wong, S. H. Luk, T. W. Leung, K. K. Yuen, W. K. Sze and S. Y. Tung Tuen Mun Hospital, Tuen Mun, Hong Kong Abstract. We report the case history of a patient with a sphenoid sinus mucocoele detected by computed tomography and medical resonance imaging. The patient had a history of nasopharyngeal carcinoma, which was treated by radiotherapy more than 10 years previously. He presented with bilateral twelfth and sixth cranial nerve palsies. Local tumour recurrence was suspected. Further investigations showed that the cranial nerve palsies were caused by radiation damage and the sphenoid sinus mucocoele was an incidental finding. Sphenoid sinus mucocoele is a possible rare late complication of radiotherapy in patients with nasopharyngeal carcinoma. Keywords: Cranial nerve palsies; Late complications; Nasopharyngeal carcinoma; Radiotherapy; Recurrence; Sphenoid sinus mucocoele
Case History A 49-year-old Chinese man was referred to our department in June 1996 because of dysphagia. He had had a diagnosis of nasopharyngeal carcinoma (NPC) made in China in 1977, when he presented with headache and bilateral enlargement of the cervical neck lymph nodes. He was subsequently treated with radical radiotherapy. Details regarding the initial stage, the treatment technique and the radiation dose are unknown. The patient complained of dysphagia since 1990, which was becoming worse during 1996. He was then seen at our department. There was no history of nasal or aural symptoms and there was no significant weight loss. Physical examination showed bilateral twelfth cranial nerve palsies. No abnormal cervical lymph nodes were detected. There was no evidence of recurrence of the nasopharyngeal tumour. The provisional diagnosis was post-irradiation twelfth cranial nerve palsies. However, the patient refused further investigations. We then referred him to a speech therapist and he claimed that the dysphagia subsequently improved subjectively. The patient was lost to follow-up after August 1996, but he reattended in April 1998, complaining of diplopia over the previous few months. Physical examination then revealed bilateral sixth cranial nerve palsies in addition to the twelfth nerve palsies. Telangiectasia and atrophic Correspondence and offprint requests to: C. S. F. Wong, Department of Clinical Oncology, Tuen Mun Hospital, Tsing Chung Koon Road, Tuen Mun, Hong Kong. Fax: +852 24685097.
mucosa were found in the nasopharynx but no recurrence was noted on fibreoptic examination. The cervical lymph nodes were not palpable. In view of the past history of NPC and the finding of new cranial nerve palsies, local recurrence had to be excluded. A contrast computed tomographic (CT) scan of the nasopharynx and base of the skull was performed, which showed an expanded sphenoid sinus filled with homogeneous hyperdense material, leading to the suspicion of an
Fig. 1. Post-contrast CT scan of the brain: expanded sphenoid sinus with hyperdense content. The sinus wall is eroded.
a
b Fig. 2. (a) T1-weighted coronal and (b) T2-weightd sagittal MRI of the brain. The sphenoid sinus is expanded with T1W andT2W hyperintense material. The nasopharynx is clear of any tumour recurrence.
enhancing sphenoid tumour mass (Fig. 1). There was no abnormality in the nasopharynx. A magnetic resonance imaging (MRI) study showed a homogeneous increase in signal intensity in both T1- and T2-weighted images in the sphenoid sinus (Fig. 2). The finding was consistent with the presence of proteinous fluid and a diagnosis of sphenoid mucocoele was made. There was bone remodelling and comprehensive erosion of the sphenoid floor, with lobulated extension of the mass into the nasopharynx and posterior nares. The cavernous sinuses were not involved. No other structural lesion affecting the cranial nerves could be found. There was a generalized patchy increase in bone density over the skull base and facial bone, which was consistent with post-irradiation changes. In order to confirm the diagnosis of mucocoele and to rule out any possible tumour recurrence, biopsy of the sphenoid sinus was performed. Chronic inflammation was revealed, but no malignant cells were seen. No infection was demonstrated within the mucocoele. The cranial nerve palsies persisted after the biopsy.
Discussion Isolated sphenoid sinus mucocoeles are rare. The incidence has been reported to be 1% of all paranasal sinus mucocoeles [1]. The most common clinical symptoms are headache and visual disturbance [2]. An association between this condition and radiotherapy has rarely been reported [3,4]. Porter et al. analysed CT scan findings for the paranasal sinuses before and after radiotherapy for nasopharyngeal carcinoma [5]. They concluded that chronic sinus disease was a common late complication of radiotherapy. In 1991, Rejab et al. reported the occurrence of a sphenoid sinus mucocoele, which was found in a patient who had received radiotherapy for nasopharyngeal carci-
354
C. S. F. Wong et al.
noma 6 years previously [3]. The authors commented that the cause could have been the occlusion of the sinus ostium by scarred mucosa after radiotherapy. Their patient presented with blurring of vision, which recovered after drainage of the mucocoele. In 1997, Wong et al. also reported an occurrence of sphenoid sinus mucocoele in a patient who had received a course of radiotherapy for nasopharyngeal carcinoma more than 10 years previously [4]. The mucocoele caused compression of the pituitary– hypothalamic region. This patient developed frequent yawning attacks, which improved after drainage of the mucocoele. Our current patient presented with dysphagia of 6 years’ duration, occurring 17 years after radiotherapy. The symptom was attributed to bilateral twelfth cranial nerve palsies. He also developed diplopia 19 years after radiotherapy. Physical examination showed bilateral sixth cranial nerve palsies. King et al. analysed the details of 17 patients who developed twelfth cranial nerve palsy after radiotherapy. Radiation-induced neuropathy was the probable cause in 14; its relationship to tumour recurrence was infrequent (only 11.8%) [6]. Lee et al. reported in 1992 that the incidence of cranial nerve palsies among patients with nasopharyngeal carcinoma treated with radical radiotherapy in Hong Kong was 5% [7]. The latent interval ranged from 0.5 to 11 years. The last four cranial nerves (particularly the twelfth) were most commonly affected, followed by the sixth. The finding of both twelfth and the sixth cranial nerve palsies in our patient was compatible with the results reported by Lee et al. However, the latency of the sixth cranial nerve palsy was unusually long. One has to investigate further the cause of a new cranial nerve palsy in patients with a history of nasopharyngeal carcinoma treated by radiotherapy many years previously. Local recurrence was unlikely in our patient in view of the long time since the radiotherapy (19 years) and the normal nasopharyngeal findings on both CT scanning and MRI. Lee et al. reported in 1999 that only 9% of recurrences occur later than 5 years after radical radiotherapy [8]. Radiation-induced malignancy (e.g. sarcoma) is another possibility. In our patient, the incidental findings of mucocoele was suspected on the CT scan and was delineated well by MRI.
Conclusion Sphenoid sinus mucocoele is a possible late complication of radiotherapy in patients with nasopharyngeal carcinoma. Its presentation in such a setting may sometimes mimic recurrence, especially when it causes compression symptoms. The most common cause for new cranial nerve lesions after radical radiotherapy for NPC is radiationinduced neuropathy, but one also has to rule out local recurrence. CT scanning and MRI are useful tools in making the diagnosis. The biopsy of any lesion detected may be necessary when a diagnosis cannot be confirmed. Drainage of the mucocoele may have to be considered to relieve the symptomatic effects of compression.
References 1. Zizmor J, Noyek A. Cysts and benign tumours of the paranasal sinuses. Semin Roentgenol 1968;3:172–201. 2. Sethi DS, Lau DPC, Chan C. Sphenoid sinus mucocoele presenting with isolated oculomotor nerve palsy. J Laryngol Otol 1997;111:471–3. 3. Rejab E, Said H, Saim L, et al. Sphenoid sinus mucocoele: a possible late complication of radiotherapy to the head and neck. J Laryngol Otol 1991;105:959–60. 4. Wong KYR, Ngan KCR, Sin VC, et al. Sphenoidal sinus mucocoele and yawning after radiation treatment for nasopharyngeal carcinoma. Clin Oncol 1997;9:415–7. 5. Porter MF, Leung SF, Ambrose R, et al. The paranasal sinuses before and after radiotherapy for nasopharyngeal
carcinoma: a computer tomographic study. J Laryngol Otol 1996;110:199–22. 6. King AD, Leung SF, Teo P, et al. Hypoglossal nerve palsy in nasopharyngeal carcinoma. Head Neck 1999;21:614–9. 7. Lee AWM, Law SCK, Ng SH, et al. Retrospective analysis of nasopharyngeal carcinoma treated during 1976–1985: late complications following megavoltage irradiation. Br J Radiol 1992;65:918–28. 8. Lee AWM, Foo W, Law SCK, et al. Recurrent nasopharyngeal carcinoma: the puzzles of long latency. Int J Radiat Oncol Biol Phys 1999;44:149–56.
Received for publication May 2000 Accepted following revision July 2000
Mimicking of Local Recurrence of Nasopharyngeal Carcinoma
355