P ulmonary
Aliya N. Husain, M.D.
X. Upper Respiratory Tract
A. Inflammations
  1. Wegener's granulomatosis: This is the most common reason for biopsying the nose and/or nasopharynx. Non-ulcerated or non-normal appearing area adjacent to an ulcer should be biopsied. Cultures should always be obtained since some infections mimic WG. Histologically, there are necrotizing granulomatous inflammation and vasculitis. The granulomas are composed of lymphocytes, histiocytes and scattered giant cells with central irregular zone of necrosis. The small muscular arteries are infiltrated by lymphocytes, histiocytes and occasionally eosinophils. The lumen of the vessel is occluded. Giant cells can also be found in the vessel wall.
  2. Lymphomatoid granulomatosis: It is similar to WG, but is a neoplastic disorder in which blood vessels are involved. Histologically, there is an intense proliferation of mixed lymphoid cells, some of which are large and atypical. These are monoclonal T cells with gene rearrangement.
  3. Allergic granulomatosis and angiitis (Churg-Strauss syndrome): There is necrotizing vasculitis with allergic granulomas. The classic lesion is a palisading granuloma with a central necrotic deeply eosinophil portion. The outer rim contains histiocytes and eosinophils.
  4. Infections such as aspergillus, mucor, candida may involve the nose and paranasal sinuses in the predisposed patient e.g., diabetics and immunocompromised.
B. EsthisioneuroblastomaThis is rare tumor occurring in the upper lateral nasal wall (in the distribution of the olfactory nerve) and is composed of small blue cells, some of which form rosettes.
C. Nasopharyngeal carcinoma or lymphoepithelial carcinoma: Strongly associated with EBV. Nests of large epithelial tumor cells are surrounded by reactive small lymphocytes.
D. Laryngeal tumors
  1. Benign
    1. Vocal cord polyp (singer's nodule): This is not a neoplasm, but is a degenerative change of submucosa, which is edematous and myoid (bluish) covered by intact squamous epithelium.
    2. Squamous papillomas are composed of projections of stratified squamous epithelium with central fibrovascular cores. Human papilloma virus can be detected in many of them.
  2. Carcinoma: The vast majority of carcinomas of the larynx are squamous cell carcinomas. These are composed of infiltrating nests and sheets of large keratinizing cells.