Pathology of the Head and Neck

Larynx and Hypopharynx Chapter 7 203cidence worldwide, including developed countries,owing to the spread of the HIV infection, poor livingstandards with malnutrition, the emergence of drugresistantmycobacteria and immigration from countrieswhere tuberculosis is still endemic [61, 78, 125,184, 268, 311, 315]. Consequently, the World HealthOrganisation has declared tuberculosis to be a globalemergency [258].LT currently affects mostly males; the average ageof patients is about 50, with a history of heavy drinkingand smoking. The most common presenting symptomis dysphonia, followed by dysphagia, odynophagia,stridor, a cough, and haemoptysis, generally associatedwith more or less obvious signs of pulmonary involvement[315, 390]. The true vocal cords are most commonlyaffected, although the supraglottic region is also involved[311]. The majority of cases present as hypertrophic,exophytic, hyperaemic lesions, sometimes nodularor ulcerated.Histologically, the subepithelial stroma contains caseatinggranulomas with a central caseous necrosis, surroundedby epithelioid macrophages, Langerhans-typegiant cells and lymphocytes (Fig. 7.3) . The covering epitheliummay be normal, ulcerated or show pseudoepitheliomatoushyperplasia. Identification of Mycobacteriumtuberculosis by special stainings or molecular geneticmethods confirms the diagnosis of LB.Differential diagnosis includes a large spectrum ofgranulomatous diseases, such as sarcoidosis, cat-scratchdisease, fungal infections, Wegener’s granulomatosisand tumourous lesions. Differentiation between sarcoidosisand tuberculosis is difficult. Generally, granulomasin sarcoidosis lack caseation and stainings formycobacteria are negative. Cat-scratch disease can beruled out by the presence of rounded or stellate granulomascontaining central granular debris and neutrophils.Fungal granulomas can be confirmed by identificationof the microorganism. Granulomas in Wegener’sgranulomatosis are not closely packed, fibrinoid necrosisof collagen is prominent and vasculitis is occasionallypresent.The treatment of LT primarily consists of antituberculoustreatment, while surgical procedure is reservedfor cases of air compromise [390].7.3.2.2 Fungal InfectionsFig. 7.3. Laryngeal tuberculosis. Granulomas are composed ofepithelioid cells, Langerhans giant cells without necrosis, surroundedby mononuclear inflammatory cellsFungal infections of the larynx are very rare, but may beexpected to arise, though not exclusively, in immunocompromisedpatients. Mycotic infections tend to occuras a result of the dissemination of the fungi, especiallyfrom the bronchopulmonary foci. An important exceptionis laryngeal candidiasis, which usually occurs as aresult of direct spread from the oral cavity [280]. Differenttypes of mycotic infections have been reported,such as laryngeal histoplasmosis [302, 319], cryptococcosis[171, 236], coccidioidomycosis [41], blastomycosis[89, 307], candidiasis [280], paracoccidioidomycosis[317] and aspergillosis [272, 310]. The histological featuresare similar for each of these infections and rangefrom granulomatous lesions related to histoplasma andcryptoccocus, to abscess formation in blastomycosisand aspergillosis [291]. Pronounced epithelial hyperplasiawith prominent ortho-parakeratosis or pseudoepitheliomatoushyperplasia in laryngeal blastomycosis,candidiasis and aspergillosis may mimic the squamouscell and verrucous cell carcinoma [272, 280, 307]. Theidentification of the causal agents by special silver, PASor mucicarmine stains of the biopsy specimens and/orcultures of microorganisms are crucial for successfultreatment.7.3.2.3 Other Rare InfectionsIn non-European countries, the larynx is occasionallyinvolved in rare infections, such as rhinoscleroma [7,100, 275], leprosy [145, 342], leishmaniasis and trichinosis[238].7.3.3 Non-InfectiousInflammatory Lesions7.3.3.1 Wegener’s GranulomatosisWegener’s granulomatosis (WG) is a systemic diseasecharacterised by necrotising vasculitis, formation ofgranulomas in the upper and lower respiratory tracts,