Immunophenotypic comparison of salivary gland oncocytoma and metastatic renal cell carcinoma

Evaluating prognosis by CK7 differentiating renal cell carcinomas from oncocytomas can be used as a promising tool for optimizing diagnosis strategies

Renal Oncocytomas and renal cell carcinomas (RCCs) share a common phenotype. This makes it very difficult to differentiate between the two tumors. Here, this study was to confirmed and expanded the findings that CK7 as a promising tool differentiate RCC from Oncocytomas across various geographic regions. A systematic search of databases was carried out and other relevant articles were also identified. Then the meta-analyses were conducted for 1,711 participants according to the standard guidelines. A total of 21 studies were included on the basis of inclusion criteria. CK7 by IHC was significantly associated with increased diagnosis of RCC (OR=10.64; 95% CI, 7.44-15.23; P=0.0001). Subgroup-analysis showed that findings didn't substantially change when only Caucasians or Asians (OR=10.58; 95% CI, 6.97-16.07; P<0.01 or OR=10.83; 95% CI, 5.39-21.74; P=0.004) were considered. There was also no significant publication bias observed. Our findings provide further evidences that the expression of CK7 contribute to differentiate RCC from Oncocytomas. CK7 protein overexpression was found in RCC, low expression in any of Oncocytomas. CK7 is potentially an important renal tumor marker.

Characterization of oncocytes in deep esophageal glands

Deep esophageal glands play a vital role in the protection and regeneration of the esophageal mucosa. Conditions such as gastroesophageal reflux disease and Barrett's esophagus have been associated with a change in the usual glands by oncocytic metaplasia. However, little is known regarding the function of oncocytes or the relevance of this metaplastic change in the human esophagus. We hypothesized that oncocytes of deep esophageal glands also express markers characteristic of a ductal epithelial phenotype because similar oncocytes have been described as part of large ductal epithelial cells in salivary glands. We used immunohistochemical stains to define structural, functional, proliferative, and potential stem/progenitor characteristics of oncocytes. Oncocytes did not express mucins or lysozyme C, two molecules found in mucous cells and used for antimicrobial defense. Oncocytes did not express CK5, a cytokeratin found in myoepithelial cells and basal epithelial cells, but expressed CK7, a cytokeratin found in intralobular ductal epithelial cells and luminal epithelial cells of the main duct. Oncocytes expressed cystic fibrosis transmembrane conductance regulator and sodium/potassium ATPase, ion channels that play a role in bicarbonate secretion. Membrane-bound beta-catenin was detected in oncocytes, but these cells did not express the proliferative marker Ki67. Approximately, a third of oncocytes expressed SOX9 and p63, transcription factors expressed in epithelial progenitor cells in multiple organs. Moreover, oncocytes expressed CD44, a transmembrane Glycoprotein expressed in cancer stem cells. Taken together, our data show that oncocytes express markers of intralobular ductal epithelial cells and luminal epithelial cells of the main duct. Additionally, our observations suggest that oncocytes act as epithelial progenitor cells and play a role in bicarbonate secretion. Since oncocytic metaplasia is associated with conditions of chronic acid injury, it is possible that oncocytes replace the mucous cells in deep esophageal glands (dEG) as an adaptive change to counteract injury from acid reflux. The marker characterization suggests that oncocytes may originate from transdifferentiation of myoepithelial and mucous cells. This transdifferentiation might lead to an overall decrease of mucins production and secretion by the dEG and a subsequent reduction of the protection conferred by the viscoelastic mucous layer.

Granular cell ameloblastoma: case report of a particular ameloblastoma histologically resembling oncocytoma

Granular cell ameloblastoma is classified as a histological subtype of solid/multicystic ameloblastoma. Usual granular cell ameloblastoma is histologically characterized by granular changes of stellate-like cells located in the inner portion of the epithelial follicles. Here we report a case of another type of granular cell ameloblastoma, showing predominant anastomosing double-stranded trabeculae of granular cells. This type of granular cell ameloblastoma is extremely rare, and the World Health Organization classification does not contain the entity. We tentatively termed it 'anastomosing granular cell ameloblastoma' in this report. The present case suggests the importance of differential diagnosis because the histology of 'anastomosing granular cell ameloblastoma' resembles that of salivary gland oncocytoma rather than that of usual granular cell ameloblastoma. The trabeculae observed in our case continued to the peripheral cells of a small amount of epithelial sheets of plexiform ameloblastoma, and the tumor cells were positive for CK19, which is regarded as an immunohistochemical marker of odontogenic epithelium. Similar to usual granular cell ameloblastoma, the tumor cells had CD68-positive granules. For precise diagnosis of this condition, immunohistochemistry using CK19 and CD68, as well as detailed histological observation, are recommended.

Metastatic tumors to the oral and maxillofacial region: a retrospective study of 19 cases in West China and review of the Chinese and English literature

PURPOSE

The aim of this article was to obtain an overview of metastatic tumors to the oral and maxillofacial (OMF) region, especially the differences in the constituent ratios of primary cancers between the United States and China.

PATIENTS AND METHODS

Clinical findings of 19 cases encountered in West China Hospital of Stomatology were summarized and the English and Chinese literature were reviewed and analyzed. The main clinical features of OMF metastases were summarized, with an emphasis on primary cancers' constituents.

RESULTS

The lung, breast, kidney, liver, and prostate were the top 5 common primary sites of cancer. However, there was a significant difference in the primary cancers' constituents between United States and China (P < .001). The breast, kidney, prostate cancers, and melanoma of skin were more frequent primary cancers in United States than in China, whereas that of the lung, thyroid, liver, esophagus, and the stomach were more common in China than in United States. The proportions of the OMF metastatic lesions originating in the lung, kidney, liver, thyroid, and esophagus in all OMF metastatic tumors were higher than the corresponding primary cancers' prevalent proportions.

CONCLUSIONS

The frequency of developing OMF metastasis is not always consistent with primary cancers' prevalence, which suggests that different cancers have different potentiality to develop OMF metastasis. Cancers of the kidney, liver, lung, thyroid, and esophagus were more likely to spread to the OMF region. In general screening of primary cancer, it would be helpful to take into account the metastatic potentiality of different cancers and primary cancers' prevalence in different countries in the case of occult primary.

Sinonasal renal cell-like adenocarcinoma: a report on four patients

BACKGROUND

We have described an unusual sinonasal neoplasm which is a histological mimic of renal cell carcinoma (RCC) and coined the nosological classification "sinonasal renal cell-like adenocarcinoma" (SRCLA) to describe this unusual entity. Since the original description (Zur et al. Otolaryngol Head Neck Surg 128:441-7, 2002), we have reviewed the case reported by Moh'd Hadi et al. (Rhinology 40:44-7, 2002) and have seen two new cases in consultation. Our purpose here is to describe the additional cases and to extend the reported outcome for these patients.

DESIGN

Four patients were identified. Slides and immunohistochemistry results were reviewed in consultation. Updated clinical follow-up was obtained from the respective clinicians.

RESULTS

This group consisted of three women, one man, 22-69 years, and mean 46. Three tumors were in the nasal cavity and one was in the nasopharynx. Histologically, these tumors were uniformly composed of clear cells, forming either solid or glandular patterns. The tumor cells were cuboidal to polyhedral; transition to short spindle cells was seen in one case. One case revealed moderate nuclear pleomorphism. No perineural or vascular invasion, or necrosis was seen. No mucin-producing or squamous elements were seen. Immunohistochemistry (IHC) revealed the following staining profile: CK7 + (4/4), CK20 + (focal 1/4), S100 + (1/4), and CD10 + (1/2). No staining was seen for vimentin (0/4), RCC (0/2), thyroglobulin (0/2), actin (0/2), or calponin (0/2). Three patients were treated primarily with surgery, two patients also received adjuvant radiotherapy (RT); the fourth patient was treated with primary RT. All patients are disease-free, based on endoscopy and/or radiography, 2, 4, 5 and 8 years after diagnosis. Renal cell carcinoma has not been identified in any patient.

CONCLUSION

Sinonasal renal cell-like adenocarcinoma is a rare and distinct entity noteworthy in its resemblance to RCC. Immunohistochemistry can easily distinguish between these two tumors. No patient developed recurrent or metastatic disease, or was found to have RCC. Greater experience will allow us to fully understand its long-term behavior and arrive at more standardized therapeutic recommendations.

p63 immunohistochemistry differentiates salivary gland oncocytoma and oncocytic carcinoma from metastatic renal cell carcinoma

Metastatic renal cell carcinoma (RCC) can pose diagnostic challenges in the head and neck often resembling benign and malignant oncocytic lesions. Immunohistochemical panels have been reported to help with this differential but are not entirely specific or sensitive. We have noticed that p63 routinely stains salivary gland oncocytomas but not metastatic RCC. Nineteen oncocytomas, 9 cases of oncocytosis, 9 oncocytic carcinomas and 16 head and neck metastatic RCC were studied. Morphologic features evaluated were cytoplasmic character (clear versus oncocytic), Fuhrman nuclear grade, mitotic rate, growth pattern, presence of lumens/blood lakes and stromal characteristics. Tumors were stained with antibodies to p63, renal cell carcinoma marker (RCCm), CD10, and vimentin. Eight benign oncocytic tumors (29%) had clear cell features while 6 metastatic RCC (37%) had oncocytic features. Median Fuhrman nuclear grade was 2 in oncocytoma and oncocytosis and 3 both oncocytic carcinoma and metastatic RCC. Mitotic rates were only significantly different between benign oncocytic tumors and metastatic RCC. All oncocytomas had lumina compared to half of metastatic RCC, all of which also demonstrated blood lakes. Seven benign oncocytic tumors (25%) and 5 oncocytic carcinomas (56%) had RCC-like vascular stroma. All primary salivary gland tumors were positive for p63, predominately in basal cell-type distribution. None of the metastatic RCC was positive. RCCm was entirely specific but lacked sensitivity for metastatic RCC while CD10 and vimentin showed variable sensitivity and specificity. While clinical history and morphology usually are adequate, demonstration of p63 staining can definitively exclude metastatic RCC from the differential diagnosis of similar appearing tumors in salivary glands, namely oncocytoma and oncocytic carcinoma, with 100% specificity and sensitivity. While RCCm, CD10, and vimentin performed adequately, they were significantly less reliable than p63 with both false positives and false negatives.

CK7+/CK20- immunoexpression profile is typical of salivary gland neoplasia

AIMS

To evaluate cytokeratin (CK) 7/20 expression patterns in salivary gland neoplasia.

METHODS AND RESULTS

Formalin-fixed paraffin embedded tissue from 153 salivary gland tumours were evaluated for CK7/20 immunoreactivity. The tumours included pleomorphic adenoma (n = 24), myoepithelioma (n = 9), papillary cystadenoma (n = 3), oncocytoma (n = 2), adenoid cystic carcinoma (n = 22), mucoepidermoid carcinoma (n = 21), polymorphous low-grade adenocarcinoma (n = 21), carcinoma ex-pleomorphic adenoma (n = 11), acinic cell carcinoma (n = 17), epimyoepithelial carcinoma (n = 7), oncocytic carcinoma (n = 3), hyalinizing clear cell carcinoma (n = 1), papillary cystadenocarcinoma (n = 1), salivary duct carcinoma (n = 3), adenocarcinoma (not otherwise specified) (n = 4) and squamous carcinoma (n = 4). Immunohistochemical procedures were performed using monoclonal antibodies CK7 (OV-TL 12/30), CK20 (Ks 20.8) and M3515 cytokeratin (AE1/AE3) in the presence of appropriate controls. The results were expressed semiquantitatively, according to the estimated percentage of positive tumour cells: 1+, 5-25%; 2+, 26-75%; and 3+, 76-100%. All salivary gland neoplasms showed a CK7+/CK20- immunoprofile ranging from 5 to 100%. Squamous carcinoma showed negative CK7/20 immunoexpression.

CONCLUSIONS

Although the CK7/20 immunoprofile is not useful in distinguishing the various types of salivary gland neoplasms or between benign and malignant salivary gland tumours, it may facilitate differentiation of primary salivary gland neoplasia from metastatic tumours and squamous carcinoma, and the diagnosis of metastatic salivary gland tumours.

Metastatic renal clear cell carcinoma in the parotid gland: a study of immunohistochemical profile and cell adhesion molecules (CAMs) expression in two cases

Metastasis of renal cell carcinoma (RCC) may involve any organ, including the parotid salivary gland. While the definition of salivary gland neoplasms with clear cell transformation can be concluded by the synchronous presence of areas showing typical morphology, sometimes the definition of a metastatic RCC in the parotid is difficult and the application of immunohistochemistry may support the clinical and radiographic observations in the final diagnosis. The aim of this paper was to describe the heterogeneous immunohistochemical features and, furthermore, to characterize the pattern of expression of cell adhesion molecules (CAMs) E-cadherin, beta4-integrin, desmoglein-2, ICAM-1 and CD44s (HCAM) in two cases of metastatic parotid RCC.

Clear cell and eosinophilic oncocytomas of salivary gland: Cytological variants or parallels?

Oncocytomas are uncommon tumors of the salivary gland. They have an abundance of mitochondria, which is manifested as granular eosinophilic cytoplasm by light microscopy. On histological sections, presence of cytoplasmic glycogen and/or fixation artifact can impart cytoplasmic clearing, and oncocytomas with a predominance of clear cytoplasm are labeled clear cell oncocytomas. Two forms of oncocytoma, eosinophilic and clear cell, have been described in the surgical pathology literature. The purpose of this manuscript is to conduct a comparative cytological assessment to ascertain parallels and differences between the two variants.

Oncocytic lipoadenoma of the parotid gland with sebaceous differentiation. Study of its keratin profile

Oncocytic lipoadenomas of salivary gland are extremely rare tumors with only two previously reported cases. In this paper, we describe an additional example of oncocytic lipoadenoma showing sebaceous differentiation, a hitherto unreported occurrence. The tumor was encapsulated and measured 3 x 2.5 x 2 cm. Microscopically, the tumor comprised a mixture of oncocytes with "light" and "dark" cells intimately associated with mature adipose tissue. The oncocytes were positive for low molecular keratin, epithelial membrane antigen (EMA), and keratin 7, with only a small subgroup of cells expressing high-molecular-weight keratin, keratin 5/6, keratin 19, and p63. Terminally differentiated sebaceous cells were positive for EMA and keratin 14 only. Calponin and actins were negative, indicating a lack of myoepithelial cells in the tumor. The keratin profile and p63 expression of this oncocytic lipoadenoma suggest the presence of a dual cell population somewhat similar to the dual cell population described in some ultrastructural studies of pure salivary gland oncocytomas and may represent partial basal-cell differentiation. The presence and nature of a dual cell population in oncocytic neoplasms of salivary glands merit further investigation to confirm these observations.