pathology of the larynx and neck Flashcards
explain Reactive nodules/polyps?
Like many other processes, these go by several different names, such as reactive nodules, vocal cord nodules, singer’s nodules, and others. Symptoms include hoarseness and change in vocal qualities. Mechanical/repetitive stress causes injury and trauma of the vocal cords, changing vocal cord mass (now with additional nodular tissue on them) and vibratory qualities.
Lesions can be bilateral on the cords (bilateral nodules are “classic” singer’s nodules)
Risk factors include chronic dehydration (mucosa becomes dryer and more easily injured), certain professions with chronic vocal use, gender (in adults, females > males), and increased laryngeal inflammation for any reason
Diagnosis is primarily by endoscopic visualization
Grossly, lesions are smooth, mucosal covered, small (usually 1-5 mm), and may be sessile/flat or pendunculated/polypoid
explain the image?
Right image: In this pedunculated reactive nodule, the submucosa shows expansion due to repetitive injury, with an intact, but thickened overlying mucosa. Reactive nodules are wound healing-like and reactive in nature, and not dysplastic or neoplastic.
What is squamous papilloma?
Similar to squamous papillomas/’warts’ in or on any other part of the body…
these show a hyperplastic squamous cell proliferation arranged in fingerlike projections with central fibrovascular cores (papillomatous hyperplasia)
these are caused by low-risk HPV (typically serotypes 6 and 11)
these can recur, or be present in multiples (papillomatosis)
Explain the image?
Image: Papillomatous hyperplasia involving a grossly polypoid laryngeal mass. The fingerlike projections show squamous mucosa with pinkish keratinization on its surface arrows), as well as abundant blue inflammatory cells in the submucosa, indicating this lesion is likely undergoing constant mechanical trauma.
What is squamous cell carcinoma?
In this SCC, smoking is most likely causative, and typical patients are older, male, and chronic smokers, and symptoms include hoarseness, dysphagia, and dysphonia. Similar to the sequence discussed in the oropharynx, lesions can progress from hyperplasia to dysplasia to neoplasia, and early lesions can grossly appear as leukoplakia, erythroplakia, or somewhat polypoid masses. As invasive SCC develops though, ulceration typically involves all or a portion of the lesion.
Somewhat in contrast to SCC in the oropharynx, highrisk HPV is seen in much less association.
HPV-association with oropharyngeal SCC: 65-70%
HPV-association with laryngeal SCC: 20-30%
Explain the image?
Image: A partially exophytic and partially ulcerated mass involves the glottis region, and extends into both infra- and supraglottic regions. Invasive SCC can develop on, above, or below the vocal cords, and may also arise on the epiglottis or aryepiglottic folds, in the pyriform sinuses, or on the pharyngeal walls. Histology would show typical invasive SCC. These days, surgical approaches are becoming more conservative than outright total laryngectomy, using limited approaches, microsurgery, and radiation when possible.
explain branchial (cleft) cyst?
Remnant of the second branchial arch embryologically (recall that branchial or pharyngeal arches are layered tissue thickenings that occur under the developing brain and give rise to the structures of the head and neck)
Usually occur in the lateral, upper neck (see image) along the sternocleidomastoid muscle, and are of variable size (but usually about 2-5 cm)
Are true cysts that are lined by stratified squamous (as in image below) or pseudostratified columnar epithelium, with a heavily inflamed, associated cyst wall
Surgical excision is typically curative
Explain a thryoglossal duct cyst?
Recall that the developing thyroid travels caudal through/with a developmental tract (the thyroglossal duct) that begins at the base of the tongue and ends near the suprasternal notch. If the thyroglossal duct doesn’t completely atrophy, its remnants can undergo cyst formation, usually in a midline location just below the hyoid bone.
Can be lined by stratified squamous or pseudostratified columnar epithelium
Cysts develop when secretions in them don’t drain and allow for infection/inflammation
Surgery is curative, although malignant transformation has been rarely reported
explain paraganglioma’s?
Recall that the carotid bodies are chemoreceptors located in the walls of both carotid arteries, near their bifurcations. The carotid bodies are neural crest-derived cells arranged in a highly vascular matrix, because they primarily detect the partial pressure of arterial oxygen, and respond by sending signals through the glossopharyngeal nerve to the respiratory centers in the brainstem, which in turn may alter respiration.
Paraganglioma is the term applied to tumors that arise in neuroendocrine cells that are in close association with the sympathetic or parasympathetic nervous system.
The carotid body is one such cluster of neuroendocrine cells, and there are many throughout the body, such as in paravertebral, parapulmonary, aortic, vagus nerve, and other head and neck locations. The most common paraganglioma is the pheochromocytoma, which is effectively an intra-adrenal paraganglioma. Paragangliomas outside of the adrenal gland are sometimes lumped under a category name called ‘extra-adrenal paraganglioma.’
Carotid body tumors are slow-growing, typically are asymptomatic or a painless mass, and are found in 50’s-60’s ages
Like neuroendocrine tumors in general, biologic is difficult to predict on histology; approximately 50% are fatal due to local or metastatic disease
explain the image?
Image: Classic appearance showing small nests of uniform cells (called the zellballen pattern) typical of neuroendocrine tumors. The delicate connective tissue septae that separate the nests have abundant capillaries, and these tumors will bleed profusely, as surgeons can attest.
Image: The nests of cells will show neuroendocrine differentiation on immunohistochemistry. In this image, chromogranin is being expressed by tumor cells, and is a known protein present in neurotransmitter dense core secretory granules.
explain what a Thymoma is?
Recall that the thymus gland is located in the anterior-superior mediastinum (further lower than the neck), and is composed of epithelial and lymphoid cells. A thymoma is a neoplasm of the epithelium of the thymus, and occasionally thymomas are located in the neck itself. This latter fact is due to the thymus developing from 3rd and 4th pharyngeal pouches (the ‘groove’ region in between branchial arches), which can allow for thymus remnants in the neck.
May become clinically evident when impingement on mediastinal or neck structures occurs
May become clinically evident in the work-up of a patient with myasthenia gravis (about 30-45% of thymoma cases)
May become clinically evident during work-up for a non-related issue
May be associated with many types of autoimmune disease (pernicious anemia, pure red cell aplasia, Graves disease, myocarditis, etc.); the abundant T lymphocytes present are thought to undergo neoplastic-induced, aberrant or hyperresponsive activation, leading to autoimmunity
explain this image?
Image: A thymoma containing few eosinophilic and neoplastic epithelial cell clusters (left half of image) and abundant non-neoplastic T lymphocytes (thymocytes). Neoplastic cells arranged in a structure resembling a Hassell corpuscle is at the arrow.
Classification schemes of thymoma?
Classification schemes of thymoma vary, but the most widely used one relies on surgerypathology correlation.
Noninvasive thymoma – not surgically invasive and histologically benign elements are present
Invasive thymoma – surgically invasive but with benign histology present
Thymic carcinoma – histologically malignant (usually SCC) and often surgical/clinical evidence of local spread or metastasis
