Oncocytic Papillary Cystadenoma with Tyrosine-rich Crystalloids in the Parotid: Case Report with Cytology and Histology Correlation and Literature Review

Abstract

Oncocytic papillary cystadenomas are rare benign salivary gland neoplasms. Minor salivary glands are frequent localization for this neoplasm. We report a case of oncocytic papillary cystadenoma of the parotid gland, occurring in a 53-year-old male as a slowly growing, well defined cystic nodule of 1.5 cm in diameter. Fine needle aspiration (FNA) was performed by using 25-gauge needle by the (cyto) pathologist. Few small sheets of epithelial and oncocytic degenerative cells with extensive granular debris on the background were observed on FNA smears. Few tabular or petal form, non-birefringent crystalloids were noted in the background of scanty cellular specimens composed predominantly of oncocytic cells. On histopathology, unilocular cystic lesion with papillary structures lined by oncocytic cells and tyrosine-rich crystalloids within the lumen were identified. In conclusion, oncocytic papillary cystadenoma is uncommon benign tumor in the parotid gland and can be accompanied by tyrosine-rich crystalloids. It is useful to be familiar with the type of the crystalloid as they may help in differentiating benign and malignant lesions. To the best of authors' knowledge, this is the second reported case of oncocytic papillary cystadenoma with crystalloids with cyto-histo correlation.

Tyrosine Crystals in Nasolabial Cyst - A Morphologic Curiosity Diagnosed at Cytology

“…Al., reviewed 97 oncocytic neoplasm and observed TC in 7 cases (14). Jamal et al described a case of oncocytic papillary cystadenoma with tyrosine crystals involving parotid gland in a 53-year-old male (6). The crystals were noted in FNAC smears and were confirmed by histopathology.…”

“…TC have never been demonstrated in nasolabial cyst. Cytology reports of TC are very few (2)(3)(4)(5)(6). Identification of these crystals at FNAC is a matter of avid observation and encouragement for cytopathologist for meticulous examination of cyst fluids obtained at FNAC procedure.…”

Synchronous Oncocytic Papillary Cystadenoma and Warthin Tumor of the Parotid Gland

“…To date, less than 15 cases of OPC of major salivary glands have been reported in literature (Table 1). [8][9][10][11][12][13][14][15][16][17][18] We describe a case of synchronous OPC and WT in the parotid gland, with relevant imaging and histological findings. To the best of our knowledge, this is the first report of such a coincidence, which highlights clinical and morphological similarities between the 2 tumors.…”