Mucoepidermoid carcinoma arising in a lymphoepithelial cyst —Report of a case and review of the literature on branchiogenic carcinoma—

Abstract

A 59-year-old Japanese man who had recently noticed a gradual enlargement in a nodule located in the left anterior part of his neck was admitted for surgical treatment. The histopathological features of the resected tumor were consistent with a typical lymphoepithelial cyst, however, the inner surface epithelium of the cyst showed histological transition to mucoepidermoid carcinoma, which was partially invading the cyst wall. Despite clinical efforts in a systemic search, no primary lesions which could have metastasized were found. The patient hasn't shown any evidence of recurrence since his tumor resection over 2 years ago. Besides this rare case report, a review of the English literature reveals 22 cases of possible branchiogenic carcinoma over the last 10 years, including 21 cases whose histological features were of squamous cell carcinoma and 1 whose histological features revealed mucoepidermoid carcinoma. The present case is thus only the second proven case of low-grade mucoepidermoid carcinoma arising within a branchiogenic cyst.

Radiographic features in lymphoepithelial cyst of the pancreas

“…It should be noted that many instances of squamous cell carcinoma or mucoepidermoid carcinoma have b e e n r e p o r t e d to arise f r o m t h e e p i t h e l i u m o f lateral n e c k b r o n c h i a l cleft cysts [11,12]. It is t h e r e f o r e p o ssible that p a n c r e a t i c l y m p h o e p i t h e l i a l cysts m a y also b e a s s o c i a t e d w i t h m a l i g n a n c y .…”

Carcinoma in situ in a lateral cervical cyst

“…Although some authors have tried to differentiate branchiogenic carcinoma based on histologic criteria such as the absence of typical lymph node structures, 16,17,20,24,29 others have denied the existence of such criteria because of possible effacement of lymph node architecture in cystic metastases. 11,12 The importance of serial sections of the specimens in the case of a benign cervical cyst to rule out focal malignant changes of the epithelium has already been emphasized.…”

Cytopathology approach to rare salivary gland lesions with oncocytic features

“…In this scenario, basaloid neoplasms of the salivary glands are suggested in the differential diagnosis . In older patients, detection of atypical squamous cells should raise the concern for metastatic squamous‐cell carcinoma of an occult head and neck primary, primary parotid squamous‐cell carcinoma, or squamous‐cell carcinoma arising from LEC's wall . In some cases of LEC, the cytopathology findings may overlap with other benign entities such as lymphoepithelial sialadenitis (LESA) .…”

“…12 In older patients, detection of atypical squamous cells should raise the concern for metastatic squamous-cell carcinoma of an occult head and neck primary, 13 primary parotid squamous-cell carcinoma, or squamous-cell carcinoma arising from LEC's wall. 14 In some cases of LEC, the cytopathology findings may overlap with other benign entities such as lymphoepithelial sialadenitis (LESA). 5 However, LESA is associated with autoimmune diseases rather than immunodeficiency, and presents as a diffuse solid mass that typically harbors lymphoepithelial sheets, in contrast to LEC.…”