الفهرس يوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
Cancer in the head and neck commonly presents as a cervical lymph node metastasis. (zitsch III and smith 2001) These patients who present with metastatic disease in the neck from an occult primary tumor remain a diagnostic and therapeutic challenge.(Dongan., 2001)
Occult primary tumors are defined as histologically proven metastatic malignant tumors whose primary site cannot be identified during pretreatment evaluation. Even after postmortem examination, the primary tumor is not identified in 20% - 50% patients (Blaszyk, et al., 2003).
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Knowledge of the levels of the lymph nodes in the neck with most common metastatic disease presentation helps the otolaryngologist tailor the search for the unknown primary (Savoury, 1991; Robbins 2002).
The number and location of lymph nodes in the neck must be assessed . The site of lymph node involvement may suggest the location of the primary tumor (Strasnick , et al., 1990).
Histopathological examination of routine haematoxylin eosin- stained tissue of the cervical lymph node mass may provide information concerning the primary site. When the metastatic tumor is undifferentiated carcinoma, it is much more difficult to find the occult primary site. Immunohistopathology can help us in this case. Differential diagnosis of a metastatic tumor with an unknown primary site starts with exclusion of malignant lymphoma. (Hainsworth et al. 1991 & Greco et al., 1997)
A thorough systemic evaluation i.e. careful history taking, physical examination including flexible fiberoptic nosolaryngoscopy evaluation will allow the primary site to be identified in most cases. When no primary site is found a high resolution imaging study such as CT or MRI is often of value in the identification of primary site among patients without any abnormal history or physical findings other than the neck mass (Zitsch III and Smith 2001).
Recent radiological studies as Positron emission tomography (PET) with fluoro-2-deoxy-D-glucose and single photon emission tomography (SPECT) allow detection of primary tumor in about 25% of cases, but this procedure is still under investigation (Gor et al., 2006).
Endoscopic examination under general anesthesia with biopsy is usually the final investigational step (Gluckman, 1998). The selection of biopsy sites should be based, in part, on suspicious areas on imaging studies and the location of the metastatic lymph nodes. (Zitsch III and Smith 2001).
The diagnosis of an occult primary tumor is made only if no primary tumor is detected after careful search, and does not appear during therapy. Patients with cervical lymph node metastases histologically related to a previously treated primary tumor are excluded (Feinmesser, et al 1992)
If a primary site is not discovered despite an extensive evaluation, and if an infraclavicular primary site is not suspected, treatment is directed at the cervical disease and potential primary sites. . (Zitsch III and Smith 2001).
Many patients presenting with squamous cell carcinoma, especially those with early stage disease is often treated with a single therapeutic modality, either radiotherapy or radical neck with the prospect of a favorable outcome. Prophylactic treatment to potential primary sites is often not delivered in these cases of limited disease when surgical management is used. (Zitsch III and Smith 2001).
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Appropriate management of the majority of patients with SCC metastatic to the neck from an unknown primary results in control of locoregional disease. Outcome has been shown to be linked to several identifiable factors. Survival decreases as tumor stage increases. Extracapsular spread in cervical metastatic nodal disease portends a worse outcome both in terms of local control and overall survival. Follow up of these patients is mandatory as they are likely to demonstrate a mucosal neoplasm over time. It is hoped that adjuvant chemotherapy will hold promise for improved outcomes, especially with advanced – stage tumor, in the near future. (Arnold and Hoffman 2001 )