The metaplastic (or infarcted) variant of Warthin's tumour is characterized by replacement of much of the original oncocytic epithelium by metaplastic squamous cells, along with areas of extensive necrosis, fibrosis and inflammatory change. The pathogenesis is unknown, but it is most likely to be vascular in origin. An association with a previous fine needle aspiration (FNA) has been suggested, and this is explored further.
Nine metaplastic Warthin's tumours were collected from several centres: all arose in the parotid gland, and all showed the characteristic histological features. Eight had previously undergone FNA some 1-4 months before surgery; the other case had had an incisional biopsy.
It is important to recognize metaplastic Warthin's tumour, because the differential diagnoses of this benign neoplasm include mucoepidermoid and squamous carcinoma, both primary and metastatic. The tumours in this study followed FNA or biopsy, and we believe this association is unlikely to be coincidental. Although many metaplastic Warthin's tumours clearly arise spontaneously, we conclude that the balance of probabilities favours the view that FNA is capable of causing metaplastic change in a Warthin's tumour, and may have done so in these cases. If so, this previously unusual subtype will become increasingly common, as FNA becomes more widely used (and its value appreciated) in the investigation of patients with a mass in the neck.
"Metaplastic WT, however, is characterized by replacement of much of the original epithelium by metaplastic squamous cells, along with regressive changes in the stroma areas (Fig. 3). Misinterpretation of metaplastic WT as a malignancy such as squamous epithelium carcinoma (PEC) or MEC presents a serious diagnostic pitfall  . The translocation t(11;19)(q21;p13) and the CRTC1eMAML2 chimeric gene have been described in MEC , in some WTs , and in some clear cell hidradenomas (CCH)  . "
[Show abstract][Hide abstract] ABSTRACT: The translocation t(11;19)(q21;p13) has been described in mucoepidermoid carcinoma (MEC) and rarely in Warthin tumors (WT), both tumors of the salivary gland. The translocation creates a fusion gene in which exon 1 of CRTC1 is linked to exons 2-5 of MAML2. To verify the translocation in WT, we performed nested reverse transcriptase-polymerase chain reaction using RNA from 48 WTs. This revealed the t(11;19)(q21;p13) translocation and expression of the chimeric gene in two metaplastic WT samples, but in none of the remaining ordinary 46 WTs. On review, the two positive cases were classified as tumors highly suspect for MEC. Indeed, our experience and published observations of the t(11;19)(q21;p13) translocation in WT reveal that only a small subset of WTs are positive, and that these tumors are often classified as infarcted or metaplastic WT, known to overlap considerably with MEC on purely morphological grounds. We therefore conclude that the presence of the t(11;19)(q21;p13) rearrangement favors a diagnosis of MEC.
Cancer Genetics and Cytogenetics 02/2008; 180(2):135-9. DOI:10.1016/j.cancergencyto.2007.10.007 · 1.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Five cases of adenolymphoma (Warthin's tumor) (AL) with numerous sarcoid-like granulomas within the lymphoid stroma are described. All patients were males, aged from 44 to 71 years (mean 57.3 years); all tumors were localized in the parotid gland. Fine needle aspiration cytology was performed in two cases 7.5 and 2 weeks before operation, respectively. Microscopic examination demonstrated the typical structure of AL. In addition, dispersed throughout the lymphoid stroma there were numerous granulomas formed by both epithelioid and multinucleated giant cells of Langhans type, strongly resembling sarcoidosis. The pathogenesis of the granulomatous change remains speculative. It could be caused by a toxic effect of the cysts' contents but probably not by its direct action; the spread of the fluid via sinuses into the lymphatic tissue seems to be more probable. We presume that the previous FNA may have some triggering effect. Granulomatous transformation of the lymphoid stroma resembling sarcoidosis is rare, but should be included in the spectrum of secondary changes in AL. It is not limited to metaplastic AL; it can be seen in an otherwise typical AL without any additional histologic changes. Knowledge of a previous FNA and awareness of the possibility of this peculiar histologic change are necessary to avoid incorrect diagnosis.
Pathology - Research and Practice 02/1999; 195(12):835-9. DOI:10.1016/S0344-0338(99)80106-X · 1.40 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Recent reports have alluded to various tissue effects secondary to fine-needle aspiration (FNA), particularly infarction observed in resected salivary gland masses, precluding accurate histologic diagnosis. Our experience with the use of 25-gauge needles indicates otherwise. We retrospectively reviewed 94 resected salivary gland masses previously sampled by FNA, looking for infarction, hemorrhage, needle track tumor seeding, and fibrosis. We assessed the significance of these complications and their impact on the histologic diagnosis. The median interval from FNA to excision was 25 days. Variable degrees of infarction and hemorrhage were present in 7 cases (7%) and 9 cases (10%), respectively. Infarction ranged from 5% to 80% (average, 20%), while hemorrhage averaged less than 20% of the material on the tissue sections. Significant infarction was present in acinic cell carcinomas (3/7), but histologic diagnosis was not compromised, and tissue alterations were absent. We conclude that FNA of salivary gland lesions using 25-gauge needles is safe and does not significantly alter the histologic diagnosis. The tissue effects observed did not preclude accurate diagnostic interpretation in any case.
American Journal of Clinical Pathology 12/2000; 114(5):741-5. DOI:10.1309/NR4U-70L7-MBDG-DXTL · 2.51 Impact Factor
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