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Benign and malignant sinonasal neoplasms: Indications and endoscopic surgical techniques
PASQUINI E.
Università degli Studi di
Bologna. Italy
Current Vision of Rhinosinusitis
and recent progress in advanced sinonasal endoscopic surgery
Medical forum. Valencia, March 2007
Keywords of Current Vision of Rhinosinusitis 2007 - PDF
LECTURES
Sinonasal endoscopic surgery constitutes a new approach to both malignant and benign tumours. It allows a different type of treatment, with minimally invasive surgery, that is associated with significant clinical benefits (and less complications). One of the world’s leading experts who has performed most research and development on this type of surgery was present at this Medical Forum. Drawing on his own personal experience, Dr. Ernesto Pasquini showed how he performs this type of surgery, suggesting possible indications and describing the technique.
RATIONALE OF THE APPROACH
The nose and paranasal cavity are complex anatomic regions which have an enormous functional and aesthetic impact for people. There are many extensive lesions that may involve the nose and paranasal cavity. The speaker divided these lesions into two groups: tumours and pseudotumours.
At present, the incidence of benign tumours of the nose and sinuses is not well established. However, there are more solid data about the incidence of malignant tumours at these sites: it is estimated that they account for 0.1%-1% of all tumours and more than 3-5% of the head and neck tumours. As a general rule, it is considered that approximately half of the tumours appearing in this region are malignant.
The benign and malignant tumours found in the nasal area show a considerable histological variety.
The benign epithelial tumours include papillomas, pleomorphic adenomas and ectopic hypophyseal adenomas; those classified as malignant include squamous cell carcinomas, undifferentiated nasopharyngeal carcinomas, papillary adenocarcinomas, intestinal adenocarcinomas, adenoid cystic carcinomas and polymorphous adenocarcinomas.
In order to determine the existence of a nasal tumour, it is absolutely necessary to perform beforehand a detailed endoscopic examination of the paranasal and nasal sinuses.
These tumours can also be distinguished by other features. These neoplasms may be primary, invasive from neighbouring structures or metastatic. This distinction is very important as it will decide the type of operation that will be performed.
On many occasions, the medical history and symptoms of this type of tumour are rather unspecific, which prevents early detection and, therefore, prompt commencement of suitable medical and/or surgical treatment. Nasal obstruction, rhinorrhoea, epistaxis, sinus pressure and pain are the most commonly associated symptoms. If the symptoms only occur on one side, it should be assumed that they are caused by a neoplastic condition until a definitive diagnosis can be established.
Likewise, any symptoms that go beyond the limits of the sinus and nasal region should be suspected as indicating a possible neoplasm. However, there are exceptions. There are diseases such as vertical diplopia and enophthalmos, which are one-sided diseases in which symptoms are initially absent or with extrasinusal symptoms that may be masking a silent sinus syndrome.
The patient’s medical history will be a key factor in arriving at a correct diagnosis. In order to determine the existence of a nasal tumour, it is absolutely necessary to perform beforehand a detailed endoscopic examination of the paranasal and nasal sinuses. This endoscopic examination not only has a diagnostic function but will also play a vital role in the patient’s follow-up.
The biopsy is a commonly used and highly effective means for obtaining an accurate diagnosis. Its use is recommended when it is suspected that there may be a tumour. In the case of nasal lesions, Dr. Pasquini recommended “performing multiple biopsies, as it is a low-risk procedure correlated with a low morbidity which enables an accurate diagnosis to be obtained.”
Along with other advice of a practical nature, the speaker added that “performing a biopsy does not have any influence on subsequent treatment and should be performed after an adequate radiologic assessment.” The biopsy will be contraindicated in special cases, such as meningoceles and meningoencephaloceles.
In the case of nasal lesions, Dr. Pasquini recommended “performing multiple biopsies, as it is a low-risk procedure correlated with a low morbidity which enables an accurate diagnosis to be obtained.
SURGICAL APPROACH
The treatment of expansive lesions of the sinonasal tract must necessarily start with the differential diagnosis between pseudotumours, benign tumours and malignant tumours. It will also be necessary to determine the tumour volume and any invasion of neighbouring structures when deciding the right treatment. In fact, as Dr. Pasquini pointed out, “some malignant tumours without invasion of extrasinusal structures can be managed using an intranasal approach, while some benign tumours (such as the osteomas) affecting the base of the anterior cranium will need more invasive approaches.”
The tumour histology and its extension will be two of the main factors that will decide the type of treatment to be used in these patients. However, in all cases, the goal of surgical treatment will always be the same: achieve complete exeresis of the tumour. Furthermore, the surgical approach must take into account functional and aesthetic aspects, so that the patient can lead a normal life after the operation.
Taking into account these aspects, and as Dr. Pasquini said, “the type of approach ultimately chosen will depend on the evaluation of a large number of factors, including the following: tumour location, tumour extension, the patient’s condition, the tumour’s histopathology, previous treatments, the patient’s preferences, and the surgeon’s experience and philosophy.”
At present, the microendoscopic approach is the gold standard for most benign tumours of the sinus tract and base of the cranium. Transnasal surgery, while assuring complete removal of the tumour, does not require any external incisions and can be performed using the endoscope and the microscope. Whether or not endoscopic instrumentation is used, this type of approach can be used in three ways: extracranial extradural, intracranial extradural or extra-intradural resection.
BENIGN TUMORS
The inverted papilloma of the nasal cavity and paranasal sinuses is a benign, probably viral neoplasm. Modifying the traditional classification proposed by Krouse, the inverted papilloma is currently stratified in five stages, each of which is associated with a particular surgical approach:
a) stage I, the disease is confined to the nasal cavity;
b) stage II, the disease is confined to the ethmoid sinus;
c) stage III, the tumour affects the antrum of the maxillary sinus, the frontoethmoid recess and the medial portion of the frontal sinus floor;
d) stage IV, the disease affects the lateral compartment of the frontal sinus or massively affects the frontal sinus;
e) stage V, the disease has spread beyond the nasal area and the paranasal sinuses, or there is a malignant lesion.
In stage I, the endoscopic resection will be limited; in stage II, the surgery of choice is ethmoidectomy or sphenoethmoidectomy; in stage III, the options are endoscopic medial maxillectomy or endoscopic DRAF II-III; in stage IV, it will be necessary to combine endoscopic and external approaches; lastly, in stage V of the inverted papilloma, endoscopic resection will only be indicated when the malignant tumour has only spread along the nasal or paranasal cavity, using external surgery with or without endoscopic support when the tumour has spread outside of the nasal area.
The treatment of expansive lesions of the sinonasal tract must necessarily start with the differential diagnosis between pseudotumours, benign tumours and malignant tumours. It will also be necessary to determine the tumour volume and any invasion of neighbouring structures when deciding the right treatment.
Juvenile angiofibroma is a highly vascularized benign mass occurring in the nasopharynx. It is relatively rare, tending to be seen in adolescent males, and is associated with nasal congestion, visible nasal mass and epistaxis. The tumour is locally invasive and can erode the bone. Surgical treatment consists of removing the tumour, which is often difficult because the tumour is not encapsulated and may be deeply invasive. It is common for the tumour to relapse after surgical resection.
As the speaker indicated, “in such cases, the endoscopic approach would be indicated.” In fact, as he reminded, “there is a consensus in the scientific literature that the endoscopic approach would be indicated in the resection of all tumours affecting the nasal cavity (Ia) and the paranasal sinuses (Ib) or when there is minimal invasion of the pterygomaxillary fossa (IIa). Its use would be limited in those cases with complete invasion of the pterygomaxillary fossa (IIb) or initial development in the posterior infratemporal fossa of the pterygoid process (IIc).”
On the basis of the speaker’s personal experience in the treatment of juvenile angiofibroma (endoscopic and/or microscopic), this type of surgery would be contraindicated when the tumour has spread intracranially or when there is invasion of the internal carotid artery or dural infiltration.
Osteoma is a rare benign bone tumour which seems to have a periosteal or juxtacortical origin. It occurs more frequently in teenagers and young adults, with a higher prevalence in males. Osteomas are usually slow growing, painless unless they exert a mechanical action on neighbouring structures, but produce a large visible and palpable bony mass. Osteomas in symptomatic patients are usually treated surgically. Osteomas of the ethmoid bone can usually be approached transnasally. It is important to assess for possible invasion of the anterior cranium base. Frontal osteoma will require in most cases an osteoplastic flap.
MALIGNANT TUMORS
There is less experience available on the endoscopic treatment of malignant sinonasal tumours. Dr. Ernesto Pasquini presented several paradigmatic case reports to describe the technique and methods used in the treatment of malignancies such as recurrent adenoid cystic carcinoma or infrastructure tumours invading the orbit. In the latter case, the Italian expert recommended radical maxillectomy, with orbital exenteration and reconstruction of the free flaps.
In the case of an ethmoid tumour without invasion of the orbital roof, the speaker recommended transnasal endoscopic resection alone. For the management of malignant tumours confined to the ethmoid bone and extending along the maxillary sinus without orbital invasion, he advised a radical endoscopic surgery based on the use of medial maxillectomy.
The craniofacial approach (alone or assisted by endoscopy) would be recommended in this type of tumour when the neoplasm is confined to the ethmoid bone and extends along the base of the anterior cranium (without invading the orbit).
By way of conclusion, Dr. Ernesto Pasquini underscored the benefits that can be obtained from the use of the endoscopic technique but warned that “this type of approach in the management of tumours should only be performed by the most experienced endoscopists, in reference centres where the other approaches that have been proven to be effective in the surgical treatment of these neoplasms are also available. In many cases, it will be necessary to combine conventional techniques with endoscopic technology.”
This type of approach in the management of tumours should only be performed by the most experienced endoscopists, in reference centres where the other approaches that have been proven to be effective in the surgical treatment of these neoplasms are also available.
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