Mudassar Majeed, Anwarul Haque.
Nasopharyngeal Carcinoma: epithelial dysplastic changes - useful clue to infiltrating malignancy.
Int J Pathol Jan ;5(2):49-53.

Introduction: Nasopharyngeal carcinoma (NPC) refers to a poorly differentiated small blue cell type squamous cell carcinoma which microscopically closely mimics lymphoma. As the management of the two lesions is quite different their separation is essential. Ancillary studies such as histochemical tests, immunostains and flow cytometry are generally employed to differentiate between the two. As infiltrating carcinomas usually follow dysplastic changes in the overlying mucosa, a significant dysplastic change in the overlying mucosa or in the adjacent glands would definitely be associated with carcinoma rather than lymphoma. A careful examination of the mucosa and the glands will thus obviate ancillary studies which may be laborious, time consuming, unnecessary and costly and thus may not be afforded by the poor patients and public sector institutions. Objective: To determine the spectrum of dysplastic changes in the overlying epithelium of the cases of infiltrating Nasopharyngeal Carcinoma that would be of help to differentiate invasive carcinoma from lymphoma without resorting to special histochemical and immunostaining thus avoiding unnecessary expenses, labor and time wasting. Materials and Methods: It is a descriptive retrospective study spanning January 2004 to June 2007 at Pathology Department, Pakistan Institute of Medical Sciences (PIMS), Islamabad. Inclusion criterion: All diagnosed cases of Nasopharyngeal carcinoma (Lymphoepithelioma). Exclusion criterion: All cases of large cell keratinizing and non-keratinizing carcinoma. Cases without overlying intact mucosa were also excluded. 27/35 cases fulfilled the inclusion criterion. Dysplasia in the overlying mucosa with intact basement membrane was evaluated. The dysplasia was graded as mild, moderate, severe, and carcinoma in situ. Whenever the glands were identified in the biopsies their epithelia were also evaluated on the same lines. Results: All cases showed significant dysplasia in the overlying mucosa. 74% cases revealed severe dysplasia to carcinoma in situ. 7 biopsies contained glands and except one all showed dysplastic changes of variable intensity in the glandular cells. Conclusion: A diagnosis of infiltrating nasopharyngeal carcinoma as opposed to lymphoma could be easily made based on dysplastic changes in the overlying mucosa in most if not in all cases and hence time, energy and money wasting ancillary studies could be avoided in these cases.

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