Intestinal-type sinonasal adenocarcinoma.
Nonintestinal-type adenocarcinomas are subclassified as low-and high-grade tumors. They are slightly more common in men than women. These tumors occur in a wide range of ages; low-grade tumors tend to occur in patients about a decade earlier than do high-grade tumors (mean ages at diagnosis: 54 and 63 yr, respectively). The ethmoid and maxillary sinuses tend to be affected more often than other sites.
ITACs are a heterogeneous group of tumors, and they are further classified into a variety of subtypes (papillary, colonic, solid, mucinous, and mixed) that are associated with clinically significant differences in outcomes. ITACs have a strong male predominance (~90% of cases), and they tend to affect older patients (mean: 60 yr). There is a well-known occupational risk after prolonged exposure (frequently decades), particularly among woodworkers and leather workers. Although the actual carcinogenic substance is unknown, it is believed to be particulate in nature, as spouses of these workers are also at increased risk. Moreover, the lower and middle turbinates are the most commonly affected areas, which suggests an initial entry point for inspired material. The most common symptoms of ITACs are unilateral obstruction, rhinorrhea, and epistaxis. These tumors tend to be identified at an early stage, thanks to a heightened awareness and industrial screening programs in associated occupations.
ITACs are made up of absorptive cells and goblet cells that form glands, nests, and abundant mucin. The degree of differentiation varies. Some are extremely well differentiated, having the appearance of a colonic tubular adenoma or villous adenoma. They have nuclear stratification and mild nuclear atypia (figure 1). Some tumors contain small intestinal-type cells, such as Paneth cells and enterochromaffin cells. Occurring at the base of the glands are a few layers of smooth-muscle cells that resemble muscularis mucosa. Other tumors resemble moderately differentiated colonic adenocarcinomas with confluent glands, nuclear pleomorphism, prominent nucleoli, and increased mitotic activity. Some tumor cells produce abundant mucinous material (figure 2). Necrosis is common. Papillary and solid patterns are also recognized. In all cases, patients should be examined for evidence of intestinal tumor before the neoplasm is accepted as a primary lesion of the upper respiratory tract.
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ITACs show keratin, EMA, B72.3, CKT, CK20, and CDX-2 immunoreactivity. CK20 and CDX-2 are both markers used to confirm intestinal (colonic) differentiation in colon primaries, and they are coexpressed in these sinonasal tract tumors (figure 3).
Schneiderian papillomas (the oncocytic variant in particular), with their complex back-to-back confluent glands and papillary architecture, may be overdiagnosed as low-grade adenocarcinomas, but the cells are cytologically benign.
Among patients with nonsalivary-gland-type adenocarcinomas, histologic grade affects outcome. Well-differentiated tumors with predominantly papillary and tubular structures are associated with a better prognosis (5-year survival: 80%) than their poorly differentiated counterparts (5-year survival: 40%). Patients whose disease is associated with occupational exposure have a better outcome than those with sporadic cases, perhaps because the former are generally under surveillance. Recurrence develops in approximately 50% of patients and distant metastasis in about 15%. Overall survival is about 40%, with death occurring in about 3 years. Treatment is radical surgical resection and postoperative radiotherapy.
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Barnes L. Intestinal-type adenocarcinoma of the nasal cavity and paranasal sinuses. Am J Surg Pathol 1986;10(3):192-202.
Kleinsasser O, Schroeder HG. Adenocarcinomas of the inner nose after exposure to wood dust. Morphological findings and relationships between histopathology and clinical behavior in 79 cases. Arch Otorhinolaryngol 1988;245(1):1-15.
Llorente JL, Perez-Escuredo J, Alvarez-Marcos C, et al. Genetic and clinical aspects of wood dust related intestinal-type sinonasal adenocarcinoma: A review. Eur Arch Otorhinolaryngol 2009;266 (1):1-7.
Lester D.R. Thompson, MD
From the Department of Pathology, Woodland Hills Medical Center, Southern California Permanente Medical Group, Woodland Hills, Calif.
Table. Classification of sinonasal adenocarcinomas Type Subtype Description Salivary- N/A Mucoepidermoid carcinoma, gland-type adenoid cystic carcinoma, acinic cell adenocarcinoma carcinoma, epithelial-myoepithelial carcinoma, clear-cell carcinoma, and polymorphous low-grade adenocarcinoma, among others Intestinal- Papillary Papillary tubular cylinder-cell type I type Colonic Papillary tubular cylinder-cell type II adenocarcinoma Solid Papillary tubular cylinder-cell type III Mucinous Alveolar goblet type and signet-ring type Mixed Transitional Nonintestinal- Low grade type High grade adenocarcinoma
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|Title Annotation:||PATHOLOGY CLINIC|
|Author:||Thompson, Lester D.R.|
|Publication:||Ear, Nose and Throat Journal|
|Date:||Jan 1, 2010|
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