Surgery for Malignant Sublingual and Minor Salivary Gland Neoplasms

Malignant sublingual gland neoplasms are rare, early-stage neoplasms presenting as painless non-ulcerated masses in the antero-lateral floor of the mouth. The majority of patients present with advanced disease, with symptoms of pain or anaesthesia of the tongue. Malignant minor salivary gland neoplasms are more common, the majority (>80%) of which present in the oral cavity, most frequently in the palatal area, as painless masses or as obstructive symptoms in the head and neck region. The most frequent pathologies are adenoid cystic carcinoma and mucoepidermoid carcinoma (>85%), with the majority presenting at an advanced stage (III/IV). Wide tumour-free surgical margin excision is the treatment of choice, followed by radiotherapy, after discussion of the multidisciplinary head and neck cancer tumour board. Improvements in survival and quality of life have been achieved since the introduction of endoscopic and robotic surgeries for many minor salivary gland malignancies.

Management of Regional Metastases of Malignant Salivary Gland Neoplasms

Metastases from salivary gland carcinomas to the cervical lymph nodes are relatively uncommon. However, their impact on prognosis is significant and, thus, it is important to manage them appropriately. Treatment of clinically evident metastases consists primarily of surgery, frequently followed by radiation. Management of the N0 neck, on the other hand, remains controversial. While there seems to be agreement regarding the tumor and patient factors that make it more likely for a patient to harbor subclinical metastases in the lymph nodes, some clinicians prefer to treat those patients with surgery, i.e. a neck dissection, and others prefer to use elective radiation. These different approaches and their rationale will be discussed in detail.

Surgery for Malignant Submandibular Gland Neoplasms

For many decades, surgery has been the primary treatment for malignant submandibular gland neoplasms. Nonetheless, due to the heterogeneity and rarity of submandibular gland malignant tumors and the high frequency of chronic benign processes in this region, management can be complex. Preoperative investigations, such as fine-needle aspiration and imaging, are critical to achieve the correct diagnosis so that appropriate surgery can be planned. In general, for malignant submandibular gland neoplasms, the minimal treatment necessary is excision of the submandibular gland with level I lymph node dissection. Salivary gland cancer in the submandibular gland is generally more aggressive than the same histologic type in the parotid gland. Neck dissection may be required and primarily depends on the stage and histological grade. Adjuvant therapy most frequently consists of radiation and can improve overall survival. Some factors that influence prognosis after surgical treatment include the histologic grade, stage at presentation, and positive surgical margins.

Frequency and Histopathology by Site, Major Pathologies, Symptoms and Signs of Salivary Gland Neoplasms

The frequency distribution of salivary gland neoplasms (SGNs) is, in decreasing order, parotid neoplasms, submandibular gland neoplasms, minor SGNs, and sublingual gland neoplasms. The larger the salivary gland (e.g. parotid), the more likely a neoplasm is benign, and the smaller the gland (e.g. minor salivary gland), the more likely the neoplasm is malignant. The majority of SGNs, benign and/or malignant, irrespective of site, present as a painless swelling or mass. Definitive symptoms and signs of salivary gland malignancy are the presence of named nerve palsy in anatomical proximity to the gland and/or the presence of cervical lymphadenopathy. All discrete major salivary gland masses and non-ulcerated submucosal masses presenting in the head and neck region, irrespective of age, should be investigated, with the aim of excluding an SGN.

Classification of Salivary Gland Neoplasms

Presently, there is no universal 'working' classification system acceptable to all clinicians involved in the diagnosis and management of patients with salivary gland neoplasms. The most recent World Health Organization Classification of Tumours: Head and Neck Tumours (Salivary Glands) (2005) for benign and malignant neoplasms represents the consensus of current knowledge and is considered the standard pathological classification based on which series should be reported. The TNM classification of salivary gland malignancies has stood the test of time, and using the stage groupings remains the current standard for reporting treated patients' outcomes. Many developments in molecular and genetic methods in the meantime have identified a number of new entities, and new findings for several of the well-established salivary malignancies need to be considered for inclusion in any new classification system. All clinicians involved in the diagnosis, assessment and treatment of patients with salivary gland neoplasms must understand and respect the need for the various classification systems, enabling them to work within a multidisciplinary clinical team environment.

Cervical lymph node metastasis in adenoid cystic carcinoma of oral cavity and oropharynx: A collective international review

The purpose of this study was to suggest general guidelines in the management of the N0 neck of oral cavity and oropharyngeal adenoid cystic carcinoma (AdCC) in order to improve the survival of these patients and/or reduce the risk of neck recurrences. The incidence of cervical node metastasis at diagnosis of head and neck AdCC is variable, and ranges between 3% and 16%. Metastasis to the cervical lymph nodes of intraoral and oropharyngeal AdCC varies from 2% to 43%, with the lower rates pertaining to palatal AdCC and the higher rates to base of the tongue. Neck node recurrence may happen after treatment in 0-14% of AdCC, is highly dependent on the extent of the treatment and is very rare in patients who have been treated with therapeutic or elective neck dissections, or elective neck irradiation. Lymph node involvement with or without extracapsular extension in AdCC has been shown in most reports to be independently associated with decreased overall and cause-specific survival, probably because lymph node involvement is a risk factor for subsequent distant metastasis. The overall rate of occult neck metastasis in patients with head and neck AdCC ranges from 15% to 44%, but occult neck metastasis from oral cavity and/or oropharynx seems to occur more frequently than from other locations, such as the sinonasal tract and major salivary glands. Nevertheless, the benefit of elective neck dissection (END) in AdCC is not comparable to that of squamous cell carcinoma, because the main cause of failure is not related to neck or local recurrence, but rather, to distant failure. Therefore, END should be considered in patients with a cN0 neck with AdCC in some high risk oral and oropharyngeal locations when postoperative RT is not planned, or the rare AdCC-high grade transformation.

Cervical Lymph Node Metastasis in High-Grade Transformation of Head and Neck Adenoid Cystic Carcinoma: A Collective International Review

Adenoid cystic carcinoma (AdCC) is among the most common malignant tumors of the salivary glands. It is characterized by a prolonged clinical course, with frequent local recurrences, late onset of metastases and fatal outcome. High-grade transformation (HGT) is an uncommon phenomenon among salivary carcinomas and is associated with increased tumor aggressiveness. In AdCC with high-grade transformation (AdCC–HGT), the clinical course deviates from the natural history of AdCC. It tends to be accelerated, with a high propensity for lymph node metastasis. In order to shed light on this rare event and, in particular, on treatment implications, we undertook this review: searching for all published cases of AdCC-HGT. We conclude that it is mandatory to perform elective neck dissection in patients with AdCC-HGT, due to the high risk of lymph node metastases associated with transformation.

Salivary Gland Neoplasms in Children and Adolescents

Salivary gland neoplasms (SGNs) in children are uncommon. Epithelial SGNs (ESGNs) comprise the majority (95%), with the remaining being mesenchymal SGNs (MeSGNs). Pleomorphic adenoma is the most frequently encountered benign neoplasm, mucoepidermoid carcinoma is the most frequent malignant ESGN, and rhabdomyosarcoma is the most frequent malignant MeSGN. ESGN presents in the second decade, whereas MeSGN presents in the first and second decades. Swelling without pain or neurological signs is the main presentation of both benign and malignant neoplasms. Making an accurate preoperative histological diagnosis is important, so a needle biopsy or a perioperative frozen section is useful when there is doubt about the disease status of the patient; the excised tumour margin is also important. Surgical excision should aim to achieve clear margin excision in benign and malignant ESGNs, minimising the need for adjuvant radiotherapy and maximising the long-term likelihood of patient cure. Benign ESGNs are uncommon, and excision is curative, whereas malignant ESGN and MeSGN should be managed by a multidisciplinary paediatric oncology team.

Cervical lymph node metastases from remote primary tumor sites

Although most malignant lymphadenopathy in the neck represent lymphomas or metastases from head and neck primary tumors, occasionally, metastatic disease from remote, usually infraclavicular, sites presents as cervical lymphadenopathy with or without an obvious primary tumor. In general, these tumors metastasize to supraclavicular lymph nodes, but occasionally may present at an isolated higher neck level. A search for the primary tumor includes information gained by histology, immunohistochemistry, and evaluation of molecular markers that may be unique to the primary tumor site. In addition, 18F-fluoro-2-deoxyglocose positron emission tomography combined with CT (FDG-PET/CT) has greatly improved the ability to detect the location of an unknown primary tumor, particularly when in a remote location. Although cervical metastatic disease from a remote primary site is often incurable, there are situations in which meaningful survival can be achieved with appropriate local treatment. Management is quite complex and requires a truly multidisciplinary approach. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2374-E2385, 2016.

Adenoid cystic carcinoma of the head and neck--An update

This article provides an update on the current understanding of adenoid cystic carcinoma of the head and neck, including a review of its epidemiology, clinical behavior, pathology, molecular biology, diagnostic workup, treatment and prognosis. Adenoid cystic carcinoma is an uncommon salivary gland tumor that may arise in a wide variety of anatomical sites in the head and neck, often with an advanced stage at diagnosis. The clinical course is characterized by very late recurrences; consequently, clinical follow-up should extend at least >15 years. The optimal treatment is generally considered to be surgery with postoperative radiotherapy to optimize local disease control. Much effort has been invested into understanding the tumor's molecular biological processes, aiming to identify patients at high risk of recurrence, in hopes that they could benefit from other, still unproven treatment modalities such as chemotherapy or biological therapy.

Vascularized tissue to reduce fistula following salvage total laryngectomy: a systematic review

OBJECTIVES/HYPOTHESIS

Pharyngocutaneous fistulae (PCF) are known to occur in nearly one-third of patients after salvage total laryngectomy (STL). PCF has severe impact on duration of admission and costs and quality of life and can even cause severe complications such as bleeding, infection and death. Many patients need further surgical procedures. The implications for functional outcome and survival are less clear. Several studies have shown that using vascularized tissue from outside the radiation field reduces the risk of PCFs following STL. This review and meta-analysis aims to identify the evidence base to support this hypothesis.

DATA SOURCES

English language literature from 2004 to 2013 REVIEW METHODS: We searched the English language literature for articles published on the subject from 2004 to 2013.

RESULTS

Adequate data was available to identify pooled incidence rates from seven articles. The pooled relative risk derived from 591 patients was 0.63 (95% CI: 0.47 to 0.85), indicating that patients who have flap reconstruction/reinforcement reduced their risk of PCF by one-third.

CONCLUSION

This pooled analysis suggests that there is a clear advantage in using vascularized tissue from outside the radiation field in the laryngectomy defect. While some studies show a clear reduction in PCF rates, others suggest that the fistulae that occur are smaller and rarely need repair.

Nodal yield in selective neck dissection

CONCLUSION

The total lymph node yield in neck dissection is highly variable and depends on anatomical, surgical and pathological parameters. A minimum yield of six lymph nodes for a selective neck dissection (SND) as recommended in guidelines lies in the lower range of the reported clinical nodal yields. A future application of a lymph node ratio may improve the risk stratification of head and neck cancer patients. However, this will require a higher number of retrieved lymph nodes.

OBJECTIVES

To compare the clinical guideline recommendations for nodal yield in SND with the number of lymph nodes obtained from cadavers and the clinical nodal yield reported in the literature.

METHODS

Lymph nodes retrieved from SND specimens from nine fresh cadavers were quantified histopathologically. The literature on nodal yields reportedly obtained by clinicians performing neck dissections was reviewed. Finally, the discussion makes reference to the six lymph nodes currently recommended in international clinical guidelines.

RESULTS

For clinical SNDs (I-III) the lowest mean nodal yield was 19.4, for SNDs (II-IV) it was 26.4. The cadaver SNDs (I-III and II-IV) yielded 8.8 (range 1-15) and 10.4 nodes (range 1-19), respectively.