Low grade parotid mucoepidermoid carcinoma with tumour associated lymphoid proliferation (“Warthin-like”) and CRTC1-MAML2 fusion transcript: Definitive diagnosis with molecular investigation only

MAML2 rearrangement as a useful diagnostic marker discriminating between Warthin tumour and Warthin-like mucoepidermoid carcinoma

“…Only newly reported cases of MEC with Warthin-like morphology were included in the analysis; thus, 7 studies reporting 20 cases were included (Table 1 [8][9][10][11][12][13][14]). Similarly, the PubMed database was searched using "Warthin MAML2" and "Warthin t(11;19)" queries (performed on 6 February 2019); subsequently, the reference lists of the included studies were also searched for further articles.…”

“…Originally, García et al reported a series of 12 oncocytic MECs in 2011 [8]. Among these, 5 were described as having Warthin-like histology (all such cases reported to date are summarized in Table 1 [8][9][10][11][12][13][14]) and harboured a mastermindlike transcriptional coactivator 2 (MAML2) rearrangement. This alteration occurs in > 50% of MECs and correlates with low-/intermediate-grade histology and a better prognosis [15].…”

“…The distinction between true WT and Warthin-like MEC is crucial as it carries vital clinical consequences. Histopathological features are usually sufficient to obtain the definitive diagnosis; however, recently, Akaev et al reported a case of MEC with tumour-associated lymphoid proliferation indistinguishable from benign WT by histology and immunohistochemistry [13]. To date, all reported cases of Warthin-like MEC have been associated with MAML2 rearrangements; thus, the molecular test may provide the definitive answer [12].…”

Fine‑needle aspiration cytology of Warthin‑like mucoepidermoid carcinoma: A case report with cytological review

“…The present study reported the sixth cytological Warthin-like MEC case. To the best of our knowledge, only 22 cases, including the present case, have been reported since the first report by Ishibashi et al (3) in 2015 (8)(9)(10)(11)(12)(13)(14)(15). Table I summarizes the clinicopathological features of Warthin-like MEC.…”

“…Fine-needle aspiration (FNA) cytology is a useful technique for diagnosing salivary gland tumours (5)(6)(7). However, the cytological features of Warthin-like MEC have remained to be fully established due to its rarity (8)(9)(10)(11). In the present study, the sixth cytological case of Warthin-like MEC was reported, which occurred in a 16-year-old Japanese female.…”