Hematopoietic Neck Lesions

Key points

  • Lymphoma should be suspected in cases of painless unilateral enlarging neck mass.

  • Lymphoma is generally categorized into both Hodgkin and Non-Hodgkin lymphoma.

  • Open biopsy allows complete lymph node architectural and cytologic evaluation.

  • The spinal accessory nerve can inadvertently be injured during supraclavicular lymph node biopsy.

  • Current therapies for lymphoma include chemotherapy with/without local field radiotherapy.

Introduction

The head and neck contain approximately 300 lymph nodes. Both benign and malignant disease can cause enlargement of these cervical lymph nodes. Lymphoproliferative neck masses account for approximately 5% of all head and neck malignancies. Often these cancers present as painlessly enlarging unilateral neck masses. Lymphoma is generally classified into Hodgkin lymphoma (HL) or non-Hodgkin lymphoma (NHL). These disease categories are associated with specific histologic features, genetic profiles, and epidemiologic links. For example, the large, owl-eyed, multinucleated Reed-Sternberg cells are a hallmark of HL, but are not seen in NHL, in which significant morphologic heterogeneity is found between subtypes, including anaplastic large cell lymphoma and diffuse large B-cell lymphoma (DLBCL). Occurrence of NHL within extranodal sites within the head and neck (ie, Waldeyer’s ring) is reported in approximately 30% of cases. Accurate diagnosis is essential to identify the correct cytologic and biochemical markers and allow proper treatment to include both chemotherapy and radiotherapy. This article focuses on presentation of lymphoma within the head and neck, various biopsy techniques, and a brief overview of current therapies in the management of lymphoma/hematopoietic malignancies.

Introduction

The head and neck contain approximately 300 lymph nodes. Both benign and malignant disease can cause enlargement of these cervical lymph nodes. Lymphoproliferative neck masses account for approximately 5% of all head and neck malignancies. Often these cancers present as painlessly enlarging unilateral neck masses. Lymphoma is generally classified into Hodgkin lymphoma (HL) or non-Hodgkin lymphoma (NHL). These disease categories are associated with specific histologic features, genetic profiles, and epidemiologic links. For example, the large, owl-eyed, multinucleated Reed-Sternberg cells are a hallmark of HL, but are not seen in NHL, in which significant morphologic heterogeneity is found between subtypes, including anaplastic large cell lymphoma and diffuse large B-cell lymphoma (DLBCL). Occurrence of NHL within extranodal sites within the head and neck (ie, Waldeyer’s ring) is reported in approximately 30% of cases. Accurate diagnosis is essential to identify the correct cytologic and biochemical markers and allow proper treatment to include both chemotherapy and radiotherapy. This article focuses on presentation of lymphoma within the head and neck, various biopsy techniques, and a brief overview of current therapies in the management of lymphoma/hematopoietic malignancies.

Preoperative planning

The incidence of lymphoma has increased within the past decade. Lymphomas are generally categorized into 2 subtypes. HL, identified microscopically by the presence of Reed-Sternberg cells, often presents as a painless neck mass resulting from enlarged cervical lymph nodes. HL rarely involves the Waldeyer’s ring or other head and neck extranodal sites. Often a single nodal chain is identified with spread to contiguous lymph nodes. In contrast, NHL has a higher incidence of extranodal presentation (30%) to include Waldeyer’s ring, nasopharynx, and tongue base. Other sites within the head and neck include the oral cavity, paranasal sinuses, orbit, salivary glands, and thyroid gland. Lymphoma within the thyroid gland accounts for approximately 5% to 10% of all thyroid masses, often presenting with a rapidly enlarging thyroid mass, hoarseness, or dysphagia.

Indolent lymphomas present as painless, slow-growing lymphadenopathy. Aggressive lymphoma presents as a rapidly growing mass with symptoms that depend on location, and can often invade vital structures.

Constitutional or B symptoms (fever, weight loss, and night sweats) are more often found in HL and can help clinicians to differentiate a suspicious neck mass from the more common cause of metastatic squamous carcinoma. Decreased appetite, pruritic skin rash, and fatigue can also accompany these B symptoms.

A neck mass suspected of lymphoma requires a thorough evaluation to include a complete history and physical examination, imaging, cytologic analysis (tissue biopsy), and bone marrow biopsy.

Imaging of the neck mass can include computed tomography (CT) scan, MRI, PET scan, and ultrasonography. In general, contrast-enhanced CT scan is the most common modality used to image a neck mass suspected to be lymphoma because it is necessary for tumor staging ( Fig. 1 ). NHL nodes are often described as multiple small 1-cm to 2-cm nonnecrotic nodes involving multiple nodal chains within the neck (occipital, retropharyngeal, levels II–V). There is often an enlarged dominant node that can range in size from 3 to 10 cm. Larger nodes with necrotic cores must be distinguished from squamous cell carcinomatous adenopathy, aggressive NHL, or lymphoma associated with acquired immunodeficiency syndrome. Nodal metastases from a distant primary, such as lung cancer or breast cancer, can be indistinguishable from NHL adenopathy on CT scan.

Fig. 1
CT scan of lymphoma involving both the tonsil and cervical lymph nodes.
( Courtesy of Robert Morales, MD, Division of Neuroradiology, University of Maryland, Baltimore, MD.)

The 2 main methods of establishing a tissue diagnosis include fine-needle aspiration biopsy (FNAB) and open biopsy technique. FNAB has the advantages of avoiding scars and minimizing risk to vital neck structures and bleeding risk. FNAB can often be combined with imaging, such as ultrasonography or CT scan, to improve accuracy of tissue sampling. Complete nodal architectural evaluation and subtype classification rates have been reported in various studies with 60% to 90% accuracy using ultrasonography-guided core biopsy ( Figs. 2 and 3 ).

Fig. 2
Ultrasonography biopsy of suspected lymphoma within a thyroid mass.
( Courtesy of Jade Wong MD, Department of Radiology, University of Maryland, Baltimore, MD.)

Fig. 3
Ultrasonography biopsy of suspected lymphoma within a neck mass. ( A ) Ultrasound guided needle biopsy of neck mass ( B ) White arrow demonstrates the needle passing into suspected lymphoma neck mass on ultrasound imaging.
( Courtesy of Jade Wong, MD, Department of Radiology, University of Maryland, Baltimore, MD.)

Limitations of fine-needle aspiration biopsy

  • Does not allow evaluation of nodal architecture

  • Unable to provide histologic subtype because of inadequate sample

  • Difficult to distinguish between reactive nodal hyperplasia and low-grade NHL

  • Difficult to diagnose HL because of the required identification of Reed-Sternberg cells (not abundant within the tissue sample)

  • Even when combined with flow cytometry, may be inadequate to diagnose disease

Open biopsy surgical technique

Despite the advantages of FNAB, open biopsy is still considered the gold standard for diagnosis of lymphoma because it provides an adequate amount of tissue for diagnosis and cytologic architectural examination. Surgical risks and complications can be minimized with careful attention to detail by experienced surgeons. Open biopsy of a neck lymph node can be performed under general anesthesia or with local anesthetic techniques. Cervical plexus nerve blockade can be used to safely perform open biopsy under local anesthesia. Most surgeons prefer to perform open biopsy under general anesthesia for patient comfort, better control in the event of significant hemorrhage, better visibility, and avoidance of possible injury to vital anatomic structures caused by patient movements.

Patient positioning

The patient is placed supine on the operating table and following induction of anesthesia the endotracheal tube is secured. Use of paralytic/muscle relaxant medications should be discussed with the anesthesia team preoperatively. Although not necessary in the identification of vital nerves (ie, marginal mandibular branch of the facial nerve, spinal accessory nerve), the ability to identify muscle twitching may help to alert the surgeon to the proximity of a named nerve and help avoid its inadvertent injury.

A shoulder roll is placed to allow neck extension and ease of access to the deeper structures of the neck if necessary. The patient is then prepped with an aseptic cleaning solution from the inferior border of the mandible to an area just inferior to the clavicles bilaterally. The patient is draped to allow exposure of cervical lymph nodes from levels I to V of the neck. Incisions are based on the specific lymph nodes to be biopsied. Careful evaluation of the preoperative imaging (ie, CT scan) helps to guide the surgeon as to the location of biopsy and vital anatomic structures within the region, and to select the lymph nodes with the easiest access.

Level IV/V and supraclavicular lymph node access

A low horizontal incision within a neck crease centered within level V/supraclavicular region is designed. The incision is made through the skin, subcutaneous tissue, and platysma muscle. The external jugular vein may be encountered and can either be retracted or ligated and divided with suture or metal clips. The posterior border of the sternocleidomastoid (SCM) muscle should be identified and retracted medially. The greater auricular nerve is identified exiting posteriorly from the sternocleidomastoid muscle and traveling superficially within the subcutaneous tissue toward the ear. This nerve is encountered if the incision is placed more superiorly for access to lymph nodes within the superior aspect of level V (apex of the triangle bounded between the SCM and trapezius muscles). Great care must be taken to identify the spinal accessory nerve within the posterior triangle ( Figs. 4 and 5 ). This nerve often travels superficially as it enters the undersurface of the trapezius muscle. Blunt and sharp dissections are performed toward the lymph nodes with care to avoid injuring the various underlying structures. The SCM can be retracted medially and the inferior belly of the omohyoid muscle can be identified. The omohyoid muscle can either be retracted superiorly, inferiorly toward the clavicle, or divided. Once deep to this muscle the internal jugular vein, brachial plexus, phrenic nerve, and carotid artery can be encountered. The transverse cervical vessels can be a landmark to alert the surgeon that the brachial plexus is in close proximity, bounded between the anterior and middle scalene muscles deep to these vessels. The surgeon must also be aware of the thoracic duct as it enters the deep venous system (internal jugular vein) on the left side of the neck or an accessory duct on the right neck. Lymphatic tissue should be ligated carefully or cauterized adequately to help avoid a chyle leak. The apex of the lung/pleura can be located in the supraclavicular fossa, increasing the risk of inadvertent lung injury and potential pneumothorax.

Jan 23, 2017 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Hematopoietic Neck Lesions
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