Synchronous parotid and nasopharyngeal Warthin's tumors: first report of a case. (Original Article).
Only a few isolated reports of Warthin's tumor of the nasopharynx have been published in the literature. None of the patients cited in those reports had another Warthin's tumor elsewhere. We describe the case of a patient who had synchronous nasopharyngeal and parotid Warthin's tumors--a case that we believe is the first to be reported in the literature. Our case provided us with a unique opportunity to study and compare the two tumors in a single patient. Their simultaneous presence might have been more than coincidental; it is possible that these two tumors were the result of the influence of one or more unknown systemic factors on trapped salivary elements in the lymphoid stroma.
Warthin's tumor of the parotid is common, accounting for as many as 25% of all parotid tumors. (1) Extraparotid Warthin's tumor, on the other hand, is uncommon. When it has been reported, it has usually occurred in cervical lymph nodes, the oral cavity, and the larynx. (2) Only a few isolated reports of Warthin's tumor in the nasopharynx have been reported, and none of the patients cited in these reports had an associated parotid tumor. (2-4)
In this article, we describe the case of a patient who had synchronous parotid and nasopharyngeal Warthin's tumors. To our knowledge, this is the first published report of such an occurrence. This case provided us with a unique opportunity to study and compare these two tumors in a single patient.
We evaluated a 53-year-old Chinese woman who had had a 2-year history of a right upper neck mass. She had been referred to us by her general practitioner specifically to exclude nasopharyngeal carcinoma, which is common in our part of the world. Our examination revealed that the patient had a mobile 3.0 x 1.5-cm mass just behind the angle of the jaw. Nasoendoscopy also detected a 1.0-cm mass on the right side of the postnasal space. We made a clinical diagnosis of nasopharyngeal carcinoma, and we obtained a biopsy sample of the postnasal space lesion with the aid of local anesthesia and endoscopic guidance. However, histologic analysis of the mass identified it as a Warthin's tumor (figure 1). Subsequent computed tomography (CT) of the neck showed that the mass there arose from the tall of the right parotid gland (figure 2). The neck mass was also excised, via a superficial parotidectomy, and histology confirmed that it, too, was a Warthin's tumor (figure 3).
Microscopy of both tumors detected a papillary proliferation of bilayered oncocytic epithelium. The epithelium was made up of well-aligned luminal columnar cells with palisaded nuclei and a lesser amount of basal cells with round-to-ovoid nuclei and small nucleoli. The epithelium was supported by a variable amount of lymphoid stroma. The contents of the stroma ranged from prominent lymphoid follicles with germinal centers to small focal collections of lymphocytes. Immunohistochemistry of both tumors revealed a mixed population of CD2O-positive B lymphocytes and CD3-positive T lymphocytes.
According to Snyderman et al, the histologic diagnosis of Warthin's tumor rests on the observation of (1) irregular cystic spaces (with or without intracystic papillary projections) that are lined with a double layer of epithelial cells (oncocytes) and (2) lymphoid tissue between the cysts. (5) The diagnosis requires a histologic demonstration of both lymphoreticular and epithelial components--hence the alternate term, papillary cystadenoma lymphomatosum. Snyderman et al pointed out that most extraparotid Warthin's tumors--specifically, those of the oral cavity, oropharynx, larynx, maxillary sinus, and lacrimal glands, but not of the cervical lymph nodes--have lacked the lymphoid component. (5) Therefore, it would be more appropriate to call them oncocytic papillary cystadenomas. The histologic features of both the parotid and nasopharyngeal lesions in our patient satisfied these criteria and justified our diagnosis of Warthin's tumor.
The histogenesis of Warthin's tumor in the parotid gland is controversial. It is most widely believed that parotid Warthin's tumor arises from ectopic salivary duct epithelium that has become trapped in the intraparotid lymph nodes during ontogeny. Encapsulation of the parotid gland occurs late in ontogeny, and the gland develops in a loose arrangement and with intermingling of lymphoid tissue. It is unclear if the epithelial component originates in uncommitted duct reserve cells or in differentiated duct cells that have undergone anaplasia (dedifferentiation). It is also possible that the origin of the lymphocytic component is the result of an immunologic reaction to the epithelial component rather than a representation of normal non-neoplastic lymphoid tissue. (5) The immunologic theory is supported by the findings of a predominance of B lymphocytes in a pattern that is similar to that seen in reactive hyperplasia. (6,7) However, other investigators have found a predominance of T cells and have observed pat terns that are similar to that of normal lymphoreticular tissue. (8,9)
To explain the apparently paradoxical immunologic findings in Warthin's tumor, Griffiths and Dekker suggested that the cell type represents different stages in the evolution of Warthin's tumor. (3) They theorized that the initial oncocytic metaplasia in Warthin's tumor induces an early T-cell response that over time recruits a much larger B-cell population.
Yeh et al (2) and others believe that Warthin's tumor of the nasopharynx originates in components of the minor salivary glands that are trapped in a pre-existing lymphoid stroma. Chronic inflammation in the nasopharynx induces the formation of oncocytic metaplasia of the glandular tissues in the stroma. (4) On the other hand, Griffiths and Dekker believe that the lymphoid component of nasopharyngeal Warthin's tumor is unlikely to represent indigenous lymphoid tissue but rather an immune response. (3)
A Warthin's tumor in the nasopharynx is in itself rare. It follows, then, that a simultaneous Warthin's tumor in the parotid gland is even rarer. Although it is possible that the appearance of these two tumors in our patient was coincidental, it is interesting to consider a possible association.
First, it is known that nasopharyngeal carcinoma can metastasize to the parotid gland, particularly on the ipsilateral side. (10) Is it possible that the parotid Warthin's tumor in our patient represented an ipsilateral metastasis from the nasopharynx? Not likely, given that almost all Warthin's tumors are benign. Even those few extraparotid Warthin's tumors that are occasionally found in the vicinity of the parotid have not been regarded as metastatic phenomena. (11) Still, Warthin's tumors have been reported to undergo malignant transformation, which could lead to metastasis. (12) However, our patient had no histologic evidence of malignancy in either of her two tumors.
A second possibility is that one or more unknown systemic factors might have influenced the development of synchronous Warthin's tumors in our patient. This theory is more tenable than the first, given that oncocytic metaplasia has been considered to represent an early stage in the evolution of Warthin's tumors. (3) Oncocytic meta-plastic changes, in turn, can occur secondary to systemic factors such as nutritional or metabolic deficiencies, genetic factors, environmental influences, duct obstruction, or chronic inflammation. (4) Therefore, it is possible that in our patient, salivary gland elements had been trapped in the lymphoid stroma in both the parotid gland and the nasopharynx during ontogeny. Later in life, one or more systemic factors might have led to the induction of oncocytic metaplasia in these trapped salivary elements, which might have led to the formation of Warthin's tumors at both sites.
(1.) Chung YF, Khoo ML, Heng MK, et al. Epidemiology of Warthin's tumour of the parotid gland in an Asian population. Br J Surg 1999;86:661-4.
(2.) Yeh YA, Baker LL, Wang WJ, Fan K. Nasopharyngeal Warthin's tumor. Otolaryngol Head Neck Surg 1999;120:942-4.
(3.) Griffiths AP, Dekker P. Oncocytic metaplasia of the nasopharynx or extra-parotid Warthin's tumour? J Clin Pathol 1991;44:1030-2.
(4.) Kristensen S, Tveteras K, Friedmann I, Thomsen P. Nasopharyngeal Warthin's tumour: A metaplastic lesion. J Laryngol Otol 1989;103:616-9.
(5.) Snyderman C, Johnson JT, Barnes EL. Extraparotid Warthin's tumor. Otolaryngol Head Neck Surg 1986;94:169-75.
(6.) Cossman J, Deegan MJ, Batsakis JG. Warthin's tumor. B lymphocytes within the lymphoid infiltrate. Arch Pathol Lab Med 1977;101:354-6.
(7.) Tubbs RR, Sheibani K, Weiss RA, et al. Immunohistochemistry of Warthin's tumor. Am J Clin Pathol 1980;74:795-7.
(8.) Howard DR. Bagley C, Batsakis JG. Warthin's tumor: A functional immunologic study of the lymphoid cell component. Am J Otolaryngol 1982;3:15-9.
(9.) Diamond LW, Braylan RC. Cell surface markers on lymphoid cells from Warthin's tumors. Cancer 1979:44:580-3.
(10.) Low WK, Goh YH. Uncommon otological manifestations of nasopharyngeal carcinoma. J Laryngol Otol 1999;113:558-60.
(11.) Nishikawa H, Kirkham N, Hogbin BM. Synchronous extra-parotid Warthin's tumour. J Laryngol Otol 1989:103:792-3.
(12.) McClatchey KD, Appelblatt NH, Langin JL. Carcinoma in papillary cystadenoma lymphomatosum (Warthin's tumor). Laryngoscope 1982;92:98-9.
From the Department of Otolaryngology (Dr. Low) and the Department of Pathology (Dr. Ng), Singapore General Hospital.
Reprint requests: Dr. Wong-Kein Low, Department of Otolaryngology, Singapore General Hospital, Singapore 169608. Phone: 656-321-4488; fax: 65-6-226-2079; e-mail: firstname.lastname@example.org
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|Author:||Ng, Siok Bian|
|Publication:||Ear, Nose and Throat Journal|
|Date:||Dec 1, 2002|
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