Squamous cell carcinoma arising in Warthin's tumor of the parotid gland. A light, electron microscopic, and immunohistochemical study

Salivary Duct Carcinoma Arising in a Warthin Tumor of the Parotid Gland: A Rare Case Report with Review of Literature and PD-L1 Expression

Warthin's tumor is the second most common neoplasm of the parotid gland and consists of 2 components, including lymphoid stroma and glandular epithelium. Malignant transformation in this tumor is mostly seen in the lymphoid component; however, the carcinomatous transformation of the epithelial component is extremely rare. Cases of latter reported in the literature include squamous cell carcinoma, adenocarcinoma, mucoepidermoid carcinoma, oncocytic carcinoma, Merkel cell carcinoma, and undifferentiated carcinoma. We describe an extremely rare case of salivary duct carcinoma arising in a Warthin tumor in a 64-year-old male. Patient presented with an enlarging left parotid mass, biopsy of which showed salivary duct carcinoma. He subsequently underwent left parotidectomy along with left level II-IV lymph node dissection. Histology revealed both in situ as well as invasive salivary duct carcinoma arising from Warthin tumor. Immunohistochemistry showed tumor cells positive for CK7, AR, and GATA3, while p63 highlighted the myoepithelial cell layer in the in situ component. Her2 was 2+ by immunohistochemistry. In addition, PD-L1 IHC revealed positive expression with a combined positive score of 20%.

Squamous Cell Carcinoma Arising in a Parotid Warthin's Tumor: A Case Report and Literature Review

Warthin's tumor is the second most common benign neoplasm of the parotid gland. Epithelial malignant transformation of Warthin's tumor, especially to squamous cell carcinoma, is a rare event. The authors present a case report of a 57-year-old male patient with a mass in the left parotid gland. This paper documents the appearance of squamous cell carcinoma within Warthin's tumor of the left parotid gland and reviews the other similar features of 12 cases.

Squamous cell carcinoma arising from Warthin's tumor in the parotid gland

The malignant transformation of Warthin’s tumor in the parotid gland is extremely rare. In addition, among the various types of the malignant change of Warthin’s tumor, squamous cell carcinoma is the rarest one. The pathogenesis of this rare disease entity is uncertain till now. Also the most effective treatment and long-term prognosis are not yet clear. Up to present, there are a few reports that only described the pathologic and clinical features of this tumor. However, there is no report about the imaging findings of this rare tumor. We report the imaging features in a case of squamous cell carcinoma arising from Warthin’s tumor in the parotid gland.

Incidence of Non-Salivary Gland Neoplasms in Patients with Warthin Tumor: A Study of 73 Cases

Warthin tumor is the second most common benign parotid neoplasm. Its association with non-salivary gland neoplasms has been sporadically reported. We reviewed clinical records of Warthin tumor diagnosed on aspiration cytology and surgical pathology to determine if there is any association with other extra-salivary gland malignant neoplasms. Computer search was made for all cases of Warthin tumor diagnosed in the parotid gland by aspiration cytology and surgical pathology at our institution between January 2007 and August 2016. Clinical records of all cases were reviewed for any associated malignant neoplasms and any surgical follow up. All available cytology and histologic material was reviewed. Seventy-three patients (mean 66.9, M:F 1.1:1, age range 43 to 87 years) with Warthin tumor were identified. 45 (62%) were diagnosed on aspiration cytology only, 19 (26%) had cytologic diagnosis as well as concordant surgical follow up, and 9 (12%) were diagnosed based on surgical pathology only. Average age for patients with and without secondary malignancy was 70.5-years, and 63.4-years, respectively (p < 0.05). Average pack years for patients with and without secondary malignancy was 45.4, and 39.8, respectively (p > 0.05). Twenty-seven (37.0%) patients harbored a malignant neoplasm. Association of extra salivary gland malignant neoplasms in 37.0% of our cases suggest that the prevalence of secondary non-salivary neoplasms in patients harboring Warthin tumor might have been underestimated. Squamous cell carcinoma was the most commonly associated non-salivary malignant neoplasm. The association of Warthin tumor with smoking plays an important role in this increased rate of malignancy, and this is supported by the fact that smoking is highly associated with head and neck and lung cancers.

Understanding primary parotid squamous cell carcinoma - A systematic review

INTRODUCTION

The true incidence of primary parotid squamous cell carcinoma (SCC) is unknown and likely overestimated in the literature. The aim of this systematic review is to examine the diagnosis, aetiology and incidence of parotid SCC by analysing studies evaluating primary parotid SCC.

METHODS

A systematic search of Medline, EMBASE and Cochrane library was performed. A narrative synthesis was done.

RESULTS

A total of 14 observational retrospective studies on primary parotid SCC were included. There are currently no standard criteria for ascertainment of primary parotid SCC. Primary parotid SCC is thought to be due to squamous metaplasia within the ductal epithelium and subsequent invasive squamous carcinoma. Histological features that favour primary disease includes SCC confined to parotid parenchyma with no direct communication to the skin and the absence of mucin. Incidence of primary parotid SCC varied from 1.54 to 2.8 cases per million person-years. Around 30%-86% of patients recorded to have primary parotid SCC on clinical records, when scrutinised, were in fact secondary to parotid lymph node involvement following regional advancement from skin or upper aerodigestive tract SCC.

CONCLUSION

Primary parotid SCC is rare and it is currently a diagnosis of exclusion. Thorough clinical assessment including endoscopy, preoperative imaging and the scrutiny of histopathological findings allow for differentiation between primary and secondary SCC within the parotid. This thus affects both initial treatment and subsequent follow-up.

Squamous Cell Carcinoma Arising in Warthin's Tumour: A Case Report

Warthin's tumour (adenolymphoma) is a well defined salivary gland tumour which consists of epithelial and lymphoid components. However, the malignant transformation of adenolymphoma is extremely rare. We are reporting a case of squamous cell carcinoma which arose in a Warthin's tumour of the right parotid gland, to highlight its varied cytolomorphological features which can cause diagnostic problems on cytological examination. The review of the literature has been discussed.

Genomic aberrations in salivary duct carcinoma arising in Warthin tumor of parotid gland: DNA microarray and HER2 fluorescence in situ hybridization

Carcinoma arising from Warthin tumor is extremely rare. A 79-year-old man was admitted for a firm, well-defined, 5-cm left infra-auricular mass. Aspiration cytology showed many lymphohistiocytes and oncocytes in a proteinaceous background, compatible with Warthin tumor. A left superficial parotidectomy showed a solid mass around the cyst wall. The tumor cells of the solid area were arranged as infiltrative ducts with a few foci of malignant transformation. Virtual karyotyping disclosed a complex pattern of genetic aberrations with a focal amplification in 12q14-q21.2. This chromosomal region contains the MDM2 (murine double minute) gene, which regulates p53 inactivation. HER2 fluorescence in situ hybridization showed a focal amplification. Subsequently, the patient underwent total parotidectomy and ipsilateral neck dissection for a recurrence. To our knowledge, this is the first case of salivary duct carcinoma arising from Warthin tumor. The essential molecular pathway has not been reported, we presume an important role of MDM2 amplification- P53 inactivation.

Primary Merkel cell carcinoma of the parotid gland

Primary Merkel cell carcinoma (MCC) is a neuroendocrine tumor that typically affects older whites. It usually originates in the dermis, but in rare instances it has arisen in other primary sites, including the oral mucosa and the parotid gland. Explanations for the presence of MCC in these atypical locations have included theories of malignant transformation and neuroendocrine migration. We describe the case of a 35-year-old white woman who had an MCC in the parotid gland and no evidence of any other primary cutaneous lesion. A left superficial parotidectomy with facial nerve preservation was performed, and a histologic diagnosis of MCC was made. Positron-emission tomography was negative for other lesions, and postoperative radiation therapy was administered for local control. To the best of our knowledge, this is only the sixth case of a primary MCC of the parotid gland to be reported in the English-language literature; of these 6 patients, ours was by far the youngest. Otolaryngologists should be familiar with this rare but potentially fatal neoplasm.

Poorly Differentiated Carcinoma Arising in a Warthin's Tumor of the Parotid Gland: Pathogenesis, Histopathology, and Surgical Management of Malignant Warthin's Tumors

Warthin's tumor is a benign lymphoepithelial neoplasm representing 10 per cent of all parotid gland tumors. Malignant transformation of a Warthin's tumor is an extremely rare event. We report a case of a patient with poorly differentiated carcinoma arising from a Warthin's tumor, as well as review the pathogenesis, histopathology, and surgical management of malignant Warthin's tumors.

Epidermoid carcinoma arising in Warthin’s tumor

Warthin's tumor is a well-defined salivary gland neoplasm consisting of benign epithelial and lymphoid components. However, malignant transformation is extremely rare and the differential diagnosis of metastasis from an epidermoid carcinoma in Warthin's tumor is important. We present a case with epidermoid carcinoma arising in Warthin's tumor of parotid gland in a 48-year-old woman, and differential diagnosis is discussed.

Diagnostic accuracy and pitfalls in fine-needle aspiration interpretation of Warthin tumor

BACKGROUND

Despite its well-defined histologic appearance, the often variegated cytomorphologic appearance of Warthin tumor (WT) on fine-needle aspiration (FNA) may lead to an erroneous cytopathologic interpretation. In this study, the authors analyzed the potential sources of diagnostic errors and overall accuracy of FNA diagnosis of WT.

METHODS

A retrospective search of The Johns Hopkins Hospital Surgical Pathology files (1985-2001) revealed 97 patients with WT, including 31 patients who underwent prior FNA. A comprehensive review of cytopathologic material was undertaken to calculate the overall accuracy of FNA and to identify sources of diagnostic error.

RESULTS

All tumors presented in the parotid gland. Four tumors (13%) were deemed inadequate for interpretation due to insufficient material. The FNA diagnosis of WT was rendered in only 20 tumors (74%). The remaining 7 tumors (26%) were misdiagnosed on FNA as consistent with or suspicious for carcinoma or some other neoplastic process. A retrospective review of the tumors, which were over-called on FNA, showed a predominance of necrotic or cellular debris (n = 6 tumors; 22%), significant epithelial metaplasia with atypia (n = 4 tumors; 15%), background inflammation suspicious for tumor diathesis (n = 3 tumors; 11%), spindle cells (n = 1 tumor; 4%), and abundant mucin with keratinized squamous cells (n = 1 tumor; 4%).

CONCLUSIONS

FNA is moderately accurate for diagnosing WT, with a 74% accuracy rate in the current series. Cytologic misinterpretation may occur due to a lack of characteristic cytomorphologic features of WT and overabundance of one or more of the following: squamous metaplasia/atypia, mucoid/mucinous background, spindle-shaped cells, and cystic/inflammatory debris. An adequate awareness of these potential sources of erroneous diagnoses, coupled with appropriate clinical findings, may result in a higher accuracy rate.

Effects of dietary lipids on cell proliferation of murine oral mucosa

BACKGROUND

The lack of certain essential polyunsaturated fatty acids (PUFAs) induces perturbation in cell proliferation, apoptosis and dedifferentiation that could be linked to an increased protumorigenic trend. Contrarily, n-3 essential fatty acids (EFAs) arrest cell proliferation in several tumor models. According to the concept of field cancerization, multiple patches of abnormal epithelial proliferation may coexist in the vicinity of oropharyngeal neoplasms. The purpose of the present study is to determine whether certain dietary PUFAs differentially modulate the patterns of cell proliferation and apoptosis at non-tumoral sites of the oral mucosa in mice bearing DMBA induced salivary tumors. After weaning, BALB/c mice were assigned to four diets: Control (C), Corn Oil (CO), Fish (FO) and Olein (O). Two weeks later, DMBA was injected into the submandibular area. The animals were sacrificed between 94 and 184 days at 4-6 PM. Fixed samples of lip, tongue and palate were stained using H-E and a silver technique. A quantification of AgNORs in the basal (BS) and suprabasal stratum (SBS) of the covering squamous epithelia as well as of mitosis and apoptosis was performed.

RESULTS

Analysis of Variance showed greater proliferation in tongue than in palate or lip. According to the diet, a significant difference was found in the Fish Oil, in which palate exhibited fewer AgNOR particles than that of the control group, both for BS and SBS (p < 0.05 and 0.152, respectively), indicating a reduced cell proliferation.

CONCLUSIONS

These results corroborate and reaffirm that the patterns of cell proliferation, apoptosis and differentiation of the oral stratified squamous epithelium may be differentially modulated by dietary lipids, and arrested by n-3 fatty acids, as shown in several other cell populations.

Mucoepidermoid carcinoma arising in Warthin's tumor of the parotid gland

Malignant transformation of Warthin's tumor is extremely rare, although it is the second most common benign tumor of the parotid gland. We describe our experience of mucoepidermoid carcinoma arising in Warthin's tumor of the parotid gland in a 64-year-old man. He had a swelling in the left parotid-masseteric region. The removed tumor was well encapsulated and histopathologically comprised Warthin's tumor and low-grade mucoepidermoid carcinoma. The mucoepidermoid carcinoma infiltrated lymphoid stroma of the Warthin's tumor, but capsular invasion is not found. Considering the clinical course and physical examination, the lesion was diagnosed as mucoepidermoid carcinoma arising in Warthin's tumor because its features filled the criteria of malignant transformation of Warthin's tumor. There has been no recurrence or distant metastasis for 19 months. Histological change from Warthin's tumor to mucoepidermoid carcinoma may be implicated in squamous or goblet cell metaplasia of epithelial cells. It is considered that the neoplastic cells of Warthin's tumor acquire malignant genotypes simultaneously with this dual differentiation.

Merkel cell carcinoma of the parotid gland associated with Warthin tumour: report of two cases

AIMS

Two cases of Merkel cell carcinoma occurring simultaneously and in close association with a Warthin tumour of the parotid gland are reported.

METHODS AND RESULTS

The patients were a 65-year-old man and a 70-year-old man, respectively. The Merkel cell carcinoma component was immunoreactive for chromogranin and keratin 20 and contained neuroendocrine-type granules at the ultrastructural level.

CONCLUSIONS

The histogenesis of this heretofore undescribed combination is discussed.

Mucoepidermoid carcinoma involving Warthin tumor. A report of five cases and review of the literature

We describe 5 cases of mucoepidermoid carcinoma (MEC) involving Warthin tumor (WT) of the parotid gland. The WT size ranged from 1.7 to 6.0 cm. The MECs were much smaller, 0.3 to 1.7 cm. In 3 cases, the WT completely surrounded the MEC, and in 2 cases neither WT nor MEC surrounded the other. Each MEC was low grade, 3 grade I and 2 grade II. One MEC had evidence of vascular invasion. All patients underwent partial or subtotal parotidectomy with negative resection margins. Clinical follow-up (range, 8-52 months) for 3 patients showed no evidence of recurrence. The pathogenetic relationship between WT and MEC in these cases is uncertain. In 4 cases, foci of squamous or mucous metaplasia were found in the WT component, associated with mild cytologic atypia in 3 tumors. However, a direct transition from WT to MEC was not identified. In 1 case, MEC was present 45 months before WT, suggesting that the recurrent MEC involved WT coincidentally. The small size and low grade of the MEC and the negative resection margins most likely explain the good outcome for the 3 patients with clinical follow-up data available.

Mucoepidermoid carcinoma arising in Warthin's tumour of the parotid gland: report of two cases with histopathological, ultrastructural and immunohistochemical studies

AIMS

Malignant transformation of Warthin's tumour (WT) is a rare event. We present two cases of mucoepidermoid carcinoma (MEC) arising in WT in the parotid gland.

METHODS AND RESULTS

Two cases of MEC arising in WT, which were found in 185 cases of WT of the parotid gland, were investigated by light and electron microscopy, and immunohistochemistry. Both cases had largely similar macroscopic and histological features with some differences. Histologically, the tumours consisted mainly of WT with multilayered hyperplastic arrangements of oncocytic cells and focal squamous and goblet cell metaplasia. In the same tumour mass, however, the features of MEC were observed with invasion to adjacent adipose tissue. A transitional zone between WT and MEC was evident. Both patients were alive and well without evidence of recurrence 30 and 34 months after surgery, respectively. Electron microscopy revealed that cyst lining epithelial cells in WTs had abundant mitochondria whereas some of the MEC cells contained numerous tonofilaments and mucinous granules. Immunohistochemically, oncocytic cells of WTs were strongly positive for mitochondria and SalylTn was extensively stained in MECs. The labelling index for Ki67 was obviously higher in the carcinoma cells than the epithelial cells of WT.

CONCLUSIONS

Our cases confirmed the possibility of malignant transformation of the epithelial component in WT to MEC.

Sources of diagnostic error in the fine-needle aspiration diagnosis of Warthin's tumor and clues to a correct diagnosis

Squamous metaplasia and cystic degeneration in Warthin's tumor (WT) are not uncommon. A recent case of WT misdiagnosed as metastatic squamous carcinoma with cystic change prompted us to review our experience with fine-needle aspiration (FNA) of WT, with special attention given to potential sources of diagnostic pitfalls. Aspirations from 16 cases of histologically confirmed WT were retrospectively evaluated for cellularity, cell composition, and background. The FNA review diagnosis was compared with the previous FNA and corresponding tissue findings. All tumors presented in the parotid gland. The initial cytologic diagnoses were: WT in 13 cases, oncocytoma vs. low-grade mucoepidermoid carcinoma in 1, squamous carcinoma vs. branchial cleft cyst in 1, and squamous carcinoma in 1. On review, 13 cases (81%) showed typical features associated with WT: Moderate to abundant oncocytic epithelium, lymphoid stroma, background debris, and mild squamous metaplasia. In the remaining cases, one lacked a lymphoid stroma and could not be further classified (initially called "oncocytoma vs. low-grade mucoepidermoid carcinoma"). The other 2 cases contained moderate to abundant atypical squamous cells and extensive necrotic/mucoid debris, and review diagnoses were consistent with the initial cytologic diagnoses (squamous carcinoma in one, and branchial cleft cyst vs. squamous carcinoma in the other). In our series, typical features of WT were seen in 81% of cases. Atypical features are largely present as individual metaplastic squamous cells. Diagnostic errors are caused by a lack of typical features and the presence of individual atypical squamous cells in a necrotic background mimicking carcinoma. An awareness of the morphologic variation present on cytologic preparations and correlation with clinical findings should prevent erroneous interpretation in the FNA setting.

Epidermoid carcinoma arising in Warthin's tumour: a case study

We present a case of epidermoid carcinoma arising in Warthin's tumour of parotid gland in an 80-year-old woman. Light microscopy revealed small foci typical of benign Warthin's tumour with transition to epidermoid carcinoma. Immunohistochemical and ultrastructural observations confirmed the epidermoid features of the malignant cells. The differential diagnosis of a metastasis from an epidermoid carcinoma to the stroma of Warthin's tumour and also of the so-called metaplastic variant of Warthin's tumour is discussed.

Warthin's tumor-associated neoplasms: report of two cases and review of the literature

The association of Warthin's tumor with another neoplasm of a different histological type in the same salivary gland is extremely rare. The literature includes 42 such cases to date. A case of malignant lymphoma developing within Warthin's tumor and another case of oncocytoma synchronous with Warthin's tumor in the same parotid gland are reported. The relation of Warthin's tumor to other neoplasms is discussed.

Cytokeratin expression in normal and (pre)malignant head and neck epithelia: an overview

Intermediate filament proteins (IFPs) are important markers of tissue differentiation and have been receiving increasing interest, in particular, through their applicability in the characterization of malignant tumors. Cytokeratins (Cks) are a family of IFPs that are typically specific for epithelial cells. They are expressed in certain combinations depending on the type of epithelium and the degree of differentiation. This review presents a critical analysis of the available data on Ck expression in normal and (pre) neoplastic epithelia of the head and neck region. Special attention is paid to technical and cell biologic pitfalls, which can lead to false-negative or false-positive data. It appears that only a limited fraction of the reported data contributes substantially to our knowledge of IFP expression in head and neck cancer because of the use of ill-defined, often formalin-fixed and paraffin-embedded, tissue specimens, and the application of limited panels of monoclonal antibodies. It is concluded that the use of immunocytohistochemistry is promising for the differential diagnosis of head and neck tumors and contributes to our knowledge on their biologic behavior. However, documentations of more complete Ck expression patterns of normal and (pre)malignant epithelium are required, together with their correlation to clinical parameters.

Malignant Warthin's tumour: a case study

Malignant transformation of a benign Warthin's tumour (adenolymphoma) is extremely rare. The light microscopic and ultrastructural features of an adenocarcinoma arising in a Warthin's tumour in the parotid gland are described. Light microscopy demonstrated a transition zone from the benign to the malignant component, and the malignant cells revealed oncocytic features by both light- and electronmicroscopy.

Malignant adenolymphoma of the parotid gland: report of carcinomatous transformation

Malignant transformation of an adenolymphoma (Warthin's tumour) is a rare event. This paper presents a case of carcinoma arising in an adenolymphoma of the parotid gland.

Squamous carcinoma arising within a Warthin's tumour of the parotid gland

The rare case of a patient who developed a squamous carcinoma within a Warthin's tumour of the parotid gland (adenolymphoma or papillary cystadenoma lymphomatosum) is described. We have found ten previously reported cases, only four of which have shown squamous carcinomatous change.

Carcinoma arising in monomorphic adenoma of the salivary gland

A case of carcinoma arising in a membranous type of monomorphic adenoma of the parotid gland is reported, and the literature is reviewed. This may represent the first unequivocal case of carcinoma arising in a nonadenolymphomatous and nonsebaceous monomorphic adenoma of the salivary gland.