Warthin-like mucoepidermoid carcinoma of the parotid gland: Clinicopathological observation and literature review

Warthin tumor (WT)-like mucoepidermoid carcinoma resembles the histologic pattern of WT and pathologists unaware of this possibility may misdiagnose it as WT with squamous and mucous epithelium metaplasia or WT malignant transfer into mucoepidermoid carcinoma. The present study reported a case of a 41-year-old Chinese female with a solitary mass in the left parotid gland. In this case, microscopic observation revealed prominent lymph node stroma and multiple cystic structures similar to those seen in WT. However, it lacked the two layers of oncocytic epithelial tissue characteristic of WT. Furthermore, fluorescence in situ hybridization detected MAML2 rearrangement in the case. Considering the histological findings, this case was diagnosed as WT-like mucoepidermoid carcinoma. The present case report provides pathological and clinical features to differentiate it from WT malignant transition into mucoepidermoid carcinoma, WT with squamous and mucous epithelium metaplasia and non-sebaceous lymphadenoma-like mucoepidermoid carcinoma. In conclusion, WT-like mucoepidermoid carcinoma as a special subtype of mucoepidermoid carcinoma has special histological characteristics, which required further observations and more case reports to clearly define this variant.

[Report of a mucoepidermoid breast carcinoma: Presentation of a rare entity]

Salivary gland-like tumours are described in the breast but remain very rare and difficult to diagnose in this location. Only 37 cases of mucoepidermoid carcinoma have been described in the literature. We report the challenging diagnosis of a mucoepidermoid carcinoma sampled by core biopsy in a 51-year-old woman.

Expression of SOX10 in Salivary Gland Oncocytic Neoplasms: A Review and a Comparative Analysis with Other Immunohistochemical Markers

OBJECTIVES

We evaluated SOX10 (SRY-related HMG-box 10) in differentiating acinic cell carcinoma (AciCC) from other salivary gland neoplasms with oncocytic features on fine-needle aspiration cell blocks (FNA CB) and compared its performance to DOG1 (discovered on gastrointestinal stromal tumor 1).

MATERIAL AND METHODS

35 FNA CB of oncocytic salivary gland neoplasms, i.e. 13 cases of AciCC, 16 of Warthin tumor (WT), 3 of mucoepidermoid carcinoma (MEC) and 3 of oncocytoma (ONC), and 75 salivary gland resections, i.e. 26 AciCC, 7 WT, 36 MEC, 3 ONC, 2 mammary analog secretory carcinomas (MASC) and 1 papillary cystadenoma were stained for SOX10 and DOG1.

RESULTS

None of the benign oncocytic neoplasms were immunoreactive for SOX10 on CB or resection, similar to DOG1. On CB, 61.5 and 77% of AciCC were positive for SOX10 and DOG1, respectively. All surgically resected AciCC cases were positive for SOX10 and DOG1; other malignant oncocytic lesions such as MEC and MASC demonstrated variable SOX10 and DOG1 staining.

CONCLUSION

The use of SOX10 may increase the diagnostic accuracy of oncocytic lesions on FNA. In this context, SOX10 is equivalent to DOG1 in ruling out benign lesions such as WT and ONC; however, negative results for SOX10 as well as DOG1 do not favor a benign diagnosis since MEC is often negative for both markers.

Adenoid cystic carcinoma of the right main bronchus showing squamous differentiation and mimicking mucoepidermoid carcinoma: a case report

Complete dissection of tracheobronchial adenoid cystic carcinoma (TACC) by surgery alone is sometimes difficult and has a greater propensity than tracheobronchial mucoepidermoid carcinoma (TMEC) for its surgical margin to become positive. In addition, TACC is more likely to present distant metastases than TMEC. Considering these facts, TACC and TMEC should be differentiated based on histopathological examination of biopsy specimens. Herein, we present a case of 54-year-old woman with a tumor in the right main bronchus, whose biopsy specimen was difficult to diagnose as TACC or TMEC. The specimen from the rounded protrusion of the tumor showed squamous differentiation, along with the presence of glandular and basaloid cells, making morphological examination alone ineffective in rendering a definite diagnosis. Thus, the addition of immunohistochemical analysis, αSMA and CD43 expression in basaloid cells and c-kit expression in glandular cells, was useful for accurately diagnosing TACC in this case. The squamous component was considered to be neoplastic because of its increased expression of cyclin D1 and overexpression of p16. The surgically resected specimen contained typical morphology of ACC, and the diagnosis of TACC was definitely confirmed.

Sclerosing mucoepidermoid carcinoma with eosinophilia of thyroid gland in a male patient: a case report and literature review

Sclerosing mucoepidermoid carcinoma with eosinophilia (SMECE) was first described by Chan et al in 1991. It is characterized by nest or strands of epidermoid tumor cells with squamous differentiation, rare mucous cells, prominent sclerotic stroma, eosinophilic and lymphoplasmacytic infiltration, and a background of chronic lymphocytic thyroiditis in the non-neoplastic thyroid gland. It is important to recognize SMECE of thyroid and differentiate it from squamous cell carcinoma or other neoplasms with squamous differentiation/metaplasia. In published cases, the SMECE of thyroid gland predominantly occurs in women. We report a case of SMECE of thyroid in a 45-year-old male patient. All cases in male patients were Caucasian described in English literature, and our case is the first one in Asian.

Salivary gland tumors: immunohistochemical study of EGF, EGFR, ErbB-2, FAS and Ki-67

OBJECTIVE

To analyze the expression of ErbB-1 (Her-1 or EGFR), ErbB-2 (Her-2 or neu), ErbB-3 (Her-3) and ErbB-4 (Her-4) and their correlation in 3 different types of salivary gland tumors.

STUDY DESIGN

Immunohistochemical expression of epidermal growth factor (EGF), EGFR, ErbB-2, fatty acid synthase (FAS) and Ki-67 were analyzed in 41 pleomorphic adenoma (PA), in 30 mucoepidermoid carcinoma (MEC) and in 30 adenoid cystic carcinoma (ACC) and correlated with their histologic patterns.

RESULTS

EGF was more common in MEC and PA, but MEC had a higher percentage of strongly positive cases. EGFRc and EGFRm were both more frequent in MEC and ACC. Higher scores of ErbB-2c were observed in PA, followed by MEC and ACC. In contrast, higher scores of ErbB-2m were more common in MEC as compared to ACC and PA. FAS was most commonly found in PA and MEC. Moreover, MEC showed the highest percentage of strongly positive cases. Ki-67 was higher in MEC and ACC than in PA. From a correlation of immunomarkers with the histologic patterns, it was observed that cribriform ACC presented more expression of EGFR and high grade MEC showed a higher percentage of ErbB-2, FAS and Ki-67.

CONCLUSION

EGF, EGFR, ErbB-2 and FAS were commonly found and seem to be important in the tumorigenesis of salivary gland tumors, particularly in percentage of strongly positive cases. Ki-67 was higher in MEC and ACC than in PA. From a correlation of immunomarkers with the histologic patterns, it was observed that cribriform ACC presented more expression of EGFR and high grade MEC showed a higher percentage of ErbB-2, FAS and Ki-67.

CONCLUSION

EGF, EGFR, ErbB-2 and FAS were commonly found and seem to be important in the tumorigenesis of salivary gland tumors, particularly in MEC. (Anal Quant Cytol Histol 2009;31:280-287)

Correlation between the expression of thrombospondin-1 and neovascularization in mucoepidermoid carcinoma

BACKGROUND

Researchers have recently demonstrated that thrombospondin-1 (TSP-1) has an important function in regulating neovascularization. Whether it inhibits or accelerates neovascularization, however, is still controversial. We found few reports about the correlation between TSP-1 and vascularization in mucoepidermoid carcinoma. In this research, the distribution and expression of TSP-1 in mucoepidermoid carcinoma were investigated. We also analyzed (1) the correlation between the expression of TSP-1 and microvessel density (MVD), as an indicator of neovascularization activity, and (2) the effect of TSP-1 on neovascularization and tumor growth in the subcutaneous xenotransplanted model of mucoepidermoid carcinoma.

METHOD

(1) The sites and intensity of expression of TSP-1 and the MVD were analyzed in 45 cases of mucoepidermoid carcinoma after surgery by the method of streptavidin-peroxidase (SP) immunohistochemistry; and (2) recombinant human thrombospondin-1 (rhTSP-1) was injected twice a week for five consecutive weeks around the tumor in the subcutaneous xenotransplanted tumor model of mucoepidermoid carcinoma in nude mice. Each week, the tumor size was measured, in order to draw the growth curve of the xenotransplanted tumor model of mucoepidermoid carcinoma, and MVD was measured.

RESULTS

(1) The positive expression of TSP-1 protein was 57.78% (26/45). Most positive staining for TSP-1 was found in the cytoplasm of the cancer cells, while some staining occurred in the extracellular matrix. The mean MVD in 45 cases of mucoepidermoid carcinoma was 58.17 +/- 19.77 per 100 visual fields. Tumors with a high expression of TSP-1 showed a low MVD value, and the TSP-1 immunocompetence and microvessel density showed a significant negative correlation (r(s) = -0.947, P < 0.001). (2) The xenotransplanted tumors with the injection doses of 1.25, 0.75 and 0.25 microg/ml respectively were 36.97%, 53.36% and 73.61% of the size of the control group ((451 +/- 92), (651 +/- 113), (898 +/- 86) and (1220 +/- 157) mm(3) respectively, F = 53.167, P < 0.001), and their weights were respectively 35.14%, 51.35% and 70.27% of the control group ((1.3 +/- 0.5), (1.9 +/- 0.5), (2.6 +/- 0.3), and (3.7 +/- 0.7) g respectively, F = 62.669, P < 0.001). Their MVDs were 25.00%, 45.93%, and 72.20% respectively of the control group and concentration dependent (15.43 +/- 3.45, 28.35 +/- 4.24, 44.57 +/- 3.35 and 61.73 +/- 5.43 per 100 visual fields respectively, F = 54.582, P < 0.001).

CONCLUSIONS

The TSP-1 has a higher expression in mucoepidermoid carcinoma and the expression has a significant negative correlation with neovascularization. The TSP-1 inhibits neovascularization and tumor growth, and it might be a new biological therapy for treatment of patients with mucoepidermoid carcinoma.

Pigmented mucoepidermoid carcinoma, a case report and review of the literature on melanin-pigmented salivary gland tumors

This paper reports a well-differentiated mucoepidermoid carcinoma containing numerous melanocytes in the parenchyma in a middle-aged Japanese man. In addition to the characteristic histopathologic features of well-differentiated mucoepidermoid carcinoma, various-formed and -sized, pigmented cells were widely distributed in the parenchyma. Many of these were considered to be melanocytes containing melanin in their cytoplasm. Perusal of the English-language literature revealed only four cases of salivary gland tumors with parenchymal pigmentation: three mucoepidermoid carcinomas and one pleomorphic adenoma. The possible histogenesis of melanocytes in the salivary gland lesions is discussed, although no firm conclusion could be drawn.

Primary nasopharyngeal mucoepidermoid carcinoma in Japanese patients: two case reports with histochemical and immunohistochemical analysis and a review of the literature

Mucoepidermoid carcinoma is a common neoplasm of the salivary glands. Salivary gland-type neoplasms are very rare in the nasopharynx, and there are only few reports on mucoepidermoid carcinoma of the nasopharynx. Two additional cases of mucoepidermoid carcinoma arising from the nasopharynx are reported here. Case 1: the patient was a 57-year-old Japanese woman who had bloody sputum. Case 2: the patient was a 51-year-old Japanese woman who underwent resection of a nasopharyngeal tumor. Histologically, both tumors were also low-grade mucoepidermoid carcinomas with clear cells. Histochemically, the gland-like nests and mucous cells were positive for mucin staining. Immunohistochemically, the lesions were positive for cytokeratins (CKs), p63, and MUC1, but negative for alpha-smooth muscle actin and EBER mRNA. The Ki-67 labeling indices of the two tumors were 10.4% and 4.3%, respectively. The two present cases and a review of the English literature indicate that salivary gland-type neoplasms arising from the nasopahrynx are extremely rare. The prognosis of salivary gland-type carcinomas of the nasopharynx is still unknown.

Hyaluronan and its receptors in mucoepidermoid carcinoma

BACKGROUND

Hyaluronan (HA) is a prominent extracellular matrix component undergoing continuous production and degradation. Increased HA levels have been described in a variety of tumors. The objective of this study was to examine the staining patterns of HA and two of its associated receptors (CD44 and HARE) in relation to the metastatic potential of mucoepidermoid carcinoma (MC). Immunohistochemical staining of preserved surgical specimens was used.

METHODS

Tissues from 12 patients with a histologic diagnosis of salivary MC (10 parotid, one submandibular gland, one minor salivary gland) were studied. Half (six of 12) of the patients had regional metastases. Tumor, normal salivary tissue, and regional lymph nodes were stained for HA, CD44, and HARE expression. Specimens were graded for staining intensity and a percent of the specimen stained.

RESULTS

Normal salivary tissue did not demonstrate epithelial cell surface HA expression, whereas HA was expressed on tumor cells and in regional lymph nodes containing metastases. These differences were both significant using Student's t test (p < .00002, and p < .0022, respectively). Tumors with positive nodes tended to have greater cell surface HA. Decreased expression or downregulation of HARE was also noted in involved lymph nodes. No differences in CD44 expression were seen between primary specimens and lymph nodes. The observed staining patterns for CD44 and HARE were not reflective of the metastatic potential of the primary MC.

CONCLUSIONS

Increased HA expression was seen on mucoepidermoid carcinoma cells compared with adjacent normal salivary gland epithelium. This observation may assist in explaining the development of regional metastasis in these tumors. We did not identify specific HA, CD44, or HARE staining patterns in primary lesions that were predictive of regional metastases.

The role of Schwann cell differentiation in perineural invasion of adenoid cystic and mucoepidermoid carcinoma of the salivary glands

Twenty cases of adenoid cystic carcinoma (ACC) and 18 cases of mucoepidermoid carcinoma (MEC), were examined for expression of the Schwann cell markers S100 protein and glial fibrillary acidic protein (GFAP) by immunohistochemical staining. The relationship between expression of S100 and GFAP and the occurrence of perineural invasion was assessed. Ultrastructural localization of S100 and GFAP was examined by immunoelectron microscopy, and the co-expression of S100 and muscle actin by double fluorescence immunostain. Perineural invasion was found in 11 ACCs (55%) and 0 MECs (0%). S100 and GFAP were expressed in most of the ACCs but none of the MECs; the difference in the rate of perineural invasion and expression of S100 and GFAP was significant between ACC and MEC (P<0.001). There was a correlation between the expression of S100 and GFAP and perineural invasion in salivary malignancy (P<0.001). The ultrastructures of S100- and GFAP-positive cells were consistent with the characteristics of myoepithelial cells. Double fluorescence immunostain also showed that S100 and muscle actin were expressed in the same type of ACC cells. These results indicate that Schwann cell differentiation correlates with perineural invasion in salivary malignancy, and occurs in modified myoepithelial cells of ACC.

Primary adenoid squamous cell carcinoma of the oral cavity

Adenoid squamous cell carcinoma (ASCC) is an uncommon but well-recognized variant of squamous cell carcinoma that was first described by Lever in 1947. ASCC has been reported to originate in the sun-exposed skin of the head and neck and in other sites. An additional case of ASCC is reported here. The patient was a 64-year-old Japanese woman who requested examination of a reddish lesion on the left floor of the mouth. The biopsy material was diagnosed as squamous cell carcinoma. Clinical examination showed a well-circumscribed, 20 x 10 mm-sized lesion, which was categorized as cT2cN0cm 0. Tumor resection was therefore performed. Histologically, most parts of the lesion were conventional squamous cell carcinoma in situ, but the invasive part consisted of ASCC with gland-like or reticular appearance. The latter part was negative for mucin staining. Immunohistochemically, this lesion was positive for pancytokeratin, high-molecular-weight keratin, cytokeratin (CK) 7/8, CK19, E-cadherin and p53, but negative for vimentin, CK20, and S-100 protein. The Ki-67 labeling index was 50.3% in the ASCC part and 34.5% in the carcinoma in situ part. These findings and a review of the literature indicate that a gland-like feature of ASCC is associated with the loss of cell adhesion in the center of the cancer nests, and it can be confirmed simply by mucin staining to be neither an adenosquamous carcinoma nor ductal involvement of conventional squamous cell carcinoma.

Relationship between major and minor salivary gland mucoepidermoid carcinoma malignancy grading and presence of stromal myofibroblasts: immunohistochemical study

OBJECTIVE

Mucoepidermoid carcinoma (MEC) is the most common malignant salivary tumour, classified as low, intermediate and high grade. Myofibroblasts are the main stromal component and are included as prognostic factor in some tumours. The aim of this study was to evaluate the myofibroblasts in the stroma of MEC with possible relationship to malignancy grading.

METHODS

Twenty-five cases of MEC (six low grade, 11 intermediate grade, four high grade and four metastasis) were stained for vimentin, desmin and smooth muscle actin (SMA) for the identification of myofibroblasts. Transforming growth factors (TGFbeta1 and TGFbetaRII) were also assessed in our study.

RESULTS

Myofibroblasts were present in all cases, in amounts varying according to histological grading. TGFbeta1 was positive in squamous cells of intermediate grade tumours, and in the stroma of only four cases. TGFbetaRII was positive in most squamous and intermediate cells, regardless of malignancy grading.

CONCLUSIONS

Our study showed that the analysis of neoplastic stroma must be added to the studies of neoplastic cells to draw a better picture leading to tumour diagnosis and prognosis.

Cytokeratin expression in central mucoepidermoid carcinoma and glandular odontogenic cyst

Central mucoepidermoid carcinoma (MEC) is an entity whose origin is still controversial. Glandular odontogenic cyst (GOC) is a recently described lesion whose relationship to low-grade central MEC has been reported in the literature. Our aim was to assess the cytokeratin (CK) profile of central MEC and GOC, and compare the results with CK expression in salivary gland MEC and odontogenic cysts and tumors. Eighty-five cases, including 6 central MECs, 23 salivary gland MECs, 10 GOCs, 34 odontogenic cysts and 12 ameloblastomas, were studied through immunohistochemistry using eleven monoclonal anti-CK antibodies. All central MECs expressed CKs 5, 7, 8, 14, and 18 and all GOCs expressed CKs 5, 7, 8, 13, 14, and 19. Comparing CK expression from GOC and central MEC we found differences in CKs 18 (30% vs 100%) and 19 (100% vs 50%). Central MEC and GOC are probably distinct entities with CK profiles similar to lesions of glandular and odontogenic origins, respectively, and expression of CKs 18 and 19 could be useful in their differential diagnosis.

Salivary gland tumors in children and adolescents: a clinicopathologic and immunohistochemical study of fifty-three cases

OBJECTIVE

Salivary gland tumors in children and adolescents are rare. Most papers are case reports or short series of cases. The aim of this study was to analyze clinicopathological and immunohistochemical data from a large series of salivary gland tumors affecting youngsters from a single institution.

METHODS

From 1953 to 1997, 53 patients 18 years old or less with epithelial salivary gland tumors from the Hospital do Cancer A.C. Camargo were studied. Clinical and treatment data were obtained from the medical records and histological features were reviewed. Paraffin-embedded tissues were immunohistochemically analyzed for p53, PCNA, Ki-67, bcl-2, c-erbB-2, and CEA.

RESULTS

Twenty-seven tumors (51%) were benign and 26 (49%) malignant. Pleomorphic adenoma (PA) was the most common tumor type (49%), followed by mucoepidermoid carcinoma (MEC, 39.6%). The tumors were more common in female and 50.9% of the cases affected the parotid, followed by 26.4% of intraoral involvement. Immunohistochemical analysis did not show correlation with prognosis of the tumors. Twenty (74%) of the 27 patients with benign tumors were alive without evidence of disease after a mean of 16.5 years of follow up; 6 were lost of follow up and 1 died by causes not related to the disease. Nineteen (73%) of the 26 patients with malignant tumors did not show tumoral recurrence after a mean follow up of 14.3 years, and 3 (11.5%) patients died of the disease.

CONCLUSIONS

In 53 cases of epithelial salivary gland tumors in youngsters, half were malignant, with favorable prognosis. On this series, immunohistochemical expression of p53, PCNA, Ki-67, c-erbB-2, bcl-2, and CEA, were not correlated with prognosis.

Clear cells and thyroid transcription factor I reactivity in sclerosing mucoepidermoid carcinoma of the thyroid gland

Clear cells have been described in mucoepidermoid carcinoma of the salivary glands, but to our knowledge these cells have not been recognized as a distinctive component of sclerosing mucoepidermoid carcinoma with eosinophilia of the thyroid gland. We report four examples in which sclerosing mucoepidermoid carcinoma of the thyroid gland contained a minor component (10% to 30%) of clear cells. The four tumors occurred in women with Hashimoto's thyroiditis whose ages ranged from 38 to 52 years. All four patients presented with thyroid nodules, but two also had enlarged cervical lymph nodes. Although two tumors metastasized to multiple cervical lymph nodes and one recurred in the soft tissues of the neck, all four patients are disease-free 6 months to 6 years after surgical treatment. The locally aggressive behavior of the first three tumors was probably related to their size, rather than to the presence of clear cells. Microscopically, these tumors showed the classical features of sclerosing mucoepidermoid carcinoma with eosinophilia, as well as nests of clear cells that appeared to be glycogen-rich squamous cells. Although the four tumors were thyroglobulin negative, two were immunoreactive to thyroid transcription factor 1 (TTF-1), supporting the idea that they originated from squamous metaplasia of follicular epithelium rather than from solid cell nests of the ultimobranchial body.

Loss of heterozygosity on chromosome 6q correlates with decreased thrombospondin-2 expression in human salivary gland carcinomas

Since loss of heterozygosity (LOH) on the long arm of chromosome 6q is frequently observed in salivary gland carcinomas, we examined 28 salivary gland carcinomas using 24 microsat- ellite markers mapping to 6q15-27 to identify the commonly deleted region that we felt might contain one or more tumor suppressor genes. LOH was detected in at least one locus in 10 of 28 tumors (35.7%). The most frequently deleted regions occurred between D6S1581 and D6S305 (LOH cluster region 1 (LCR1) and between D6S297 and D6S1590 (LCR2). LOH was observed in 60% of adenoid cystic carcinomas (ACC) and in 57.1% of mucoepidermoid carcinomas (MEC), but was not observed in any locus in any other histological subtypes studied. The gene encoding for thrombospondin-2 (TSP-2) is located in LCR2 and 8 of 9 tumors demonstrating LOH in this region also showed significantly decreased TSP-2 expression by immunohistochemistry. As TSP-2 is a potent inhibitor of tumor growth and angiogenesis, we examined whether TSP-2 expression correlated to microvascular angiogenesis in these tumors and discovered that microvessel counts were significantly higher in lesions with decreased TSP-2 expression (P = 0.02). Our results suggest that 6q LOH may be a significant event in salivary gland carcinogenesis, particularly in ACC and MEC, and that the correlated decrease of TSP-2 expression also plays a critical role.

Expression of androgen, estrogen, and progesterone receptors in salivary gland tumors. Frequent expression of androgen receptor in a subset of malignant salivary gland tumors

The expression of sex hormone receptors in some tumors suggests a role for these receptors in tumor pathogenesis and therapy. Previous studies of the expression of estrogen and progesterone receptors in salivary gland tumors have reported conflicting results. We evaluated the immunohistochemical expression of androgen, estrogen, and progesterone receptors (AR, ER, and PR) in a series of 78 formalin-fixed, paraffin-embedded salivary gland tumors. Immunoreactivity for AR was seen in 14 of 14 carcinoma ex pleomorphic adenomas, 6 of 6 salivary duct carcinomas, and 2 of 2 basal cell adenocarcinomas but in only 2 of 10 acinic cell carcinomas, mucoepidermoid carcinomas, and adenoid cystic carcinomas each. AR expression was distributed evenly between the sexes. ER and PR were expressed in only a few cases of salivary gland tumors. All 26 benign salivary gland tumors were negative for AR, ER, and PR. The uniform expression of AR exclusively in a subset of malignant salivary gland tumors suggests a possible role for AR in the histogenesis and possibly in the clinical management of these malignant salivary gland tumors.

Immunohistochemical distinction of high-grade mucoepidermoid carcinoma and epidermoid carcinoma of the parotid region

The correct diagnosis of high-grade mucoepidermoid (MEC), which is composed of solid islands of intermediate and squamous cells, may be challenging, due to its similarity to other tumours, mainly with squamous cell carcinoma (SCC). The present report employed immunohistochemical technique against different cytokeratins (CKs), in order to differentiate these two entities. : Six high-grade MEC and six SCC of the parotid region, retrieved from the files of both Oral Pathology Department of the School of Dentistry of University of São Paulo and Pathology Department of A.C. Camargo Hospital, were submitted immunohistochemical technique against Cks 7,8, 10, 13, 14 and 19. : High-grade MEC was positive for Cks 7, 8, 13, 14 and 19. The cases of SCC showed strong positivity for CK14, and CK10 was present only in focal areas. Our results highlight the use of CKs (especially CK14) to differentiate high-grade MEC and SCC.

Mucoepidermoid carcinoma of the thyroid: a tumour histotype characterised by P-cadherin neoexpression and marked abnormalities of E-cadherin/catenins complex

The cadherin/catenins complex regulates cell-cell adhesion and motility and is believed to have an invasion suppressor role. Primary mucoepidermoid carcinoma of the thyroid (MECT) is a rare tumour characterised by a distinct morphological appearance and a questionable histogenesis. The coexistence of papillary thyroid carcinoma (PTC) foci in many patients with MECT suggests an association between the two tumour histotypes. In an attempt to clarify the putative relationship between MECT and PTC, we analysed tissue from 11 patients with MECT by immunohistochemistry (E-, P- and N-cadherins and alpha-, beta- and gamma-catenins). The E-cadherin gene was also analysed by polymerase chain reaction (PCR)/single-strand conformation polymorphism (SSCP). The results were compared with a control group of normal thyroid, classical PTC and the diffuse sclerosing variant of PTC. Compared with normal thyroid and PTC, MECT displays marked abnormalities of the cadherin/catenin complex. Such abnormalities include the consistent neoexpression of P-cadherin and major alterations in the expression of E-cadherin and the three catenins. Our results point to the close relationship between the de novo expression of P-cadherin and the disruption of the cadherin/catenins complex with the squamoid phenotype of MECT.

Low-grade mucoepidermoid carcinoma of salivary glands: characteristic immunohistochemical profile and evidence of striated duct differentiation

The purpose of the present study is to determine the presence and distribution of epithelial and myoepithelial cells in mucoepidermoid carcinoma (MEC) of salivary glands and to compare them with normal salivary gland tissue and other primary carcinomas. This is in order to establish novel diagnostic criteria and to better understand MEC histogenesis. Formalin-fixed paraffin-embedded tissues from ten well-differentiated MECs, three adenoid cystic carcinomas (ACC), four acinic cell carcinomas (AC), and three epithelial-myoepithelial carcinomas (EMCC) of salivary glands were studied with immunohistochemistry using antibodies that recognise antigens indicative of epithelial and myoepithelial cell differentiation. An anti-mitochondrial antibody was also employed. Normal salivary tissue was present for comparative study in non-tumorous areas of the same section from 12 cases. MEC contained numerous keratin-positive cells. Anti mitochondrial antibody was diffusely positive in all ten of these tumours. Smooth muscle actin, h-caldesmon, and smooth muscle heavy chain myosin, which are indicative of myoepithelial cell differentiation, were negative. Rare cells in only one case were stained by calponin. Cytokeratin 14 (CK14) and anti mitochondrial antibody stained cells located mainly at the periphery of neoplastic nests and cystic spaces, while CK7 was mainly present in cells bordering gland lumina (zoning pattern). The immunohistochemical cell profile was similar to that seen in striated normal ducts. All others tumours studied showed a different immunohistochemical pattern, mostly consisting of a lack of mitochondrion-rich cells and the presence of myoepithelial cells in ACC and EMCC. Immunoreactivity in MEC for CK7, CK14 and mitochondrial antibodies appears as a peculiar pattern of staining, different from that of other salivary gland tumors; this seems helpful for diagnostic purposes. In addition, a differentiation of the "striated duct phenotype" is suggested.

Immunohistochemical expression of CA19-9 and CA125 in mucoepidermoid and adenoid cystic carcinomas of the salivary gland

This study examined the immunohistochemical expression of carbohydrate antigens CA19-9 and CA125 and their relationship to various biological parameters in 27 mucoepidermoid carcinomas (MEC) and 18 adenoid cystic carcinomas (ACC) arising from salivary glands. The series showed higher immunopositivity for CA125 (67% for MEC; 33% for ACC) than for CA19-9 (59% for MEC; 11% for ACC). CA19-9 epitope was mainly expressed in cystic (MEC) and cribriform/tubular (ACC) components of carcinoma tissues. Solid components in MEC occasionally showed positive staining for CA19-9. CA125 was evenly expressed in both ACC and MEC tissues regardless of their different histological components. The positive expression of CA19-9 and CA125 in the carcinoma tissues did not influence the clinical course of patients with MEC and ACC. A significant relationship was only demonstrated between the immunohistochemical expression of CA125 and the low proliferative activity (LI) evaluated by Ki-67 immunohistochemistry. However, no significant relationship was found between LI and the patients' clinical course. These results suggest that the immunostaining for CA19-9 and CA125 provide no reliable data to predict the clinical course of patients with MEC and ACC of the salivary glands.

Evaluation of prognostic factors following flow-cytometric DNA analysis after cytokeratin labelling: II. Cervical and endometrial cancer

In gynecologic oncology valid prognostic factors are necessary to define biologically similar subgroups for analysis of therapeutic efficacy. This study is the first published prospective study concerning prognostic significance of DNA ploidy and S-phase fraction in cervical and endometrial cancer following enrichment of tumor cells by cytokeratin labelling. Epithelial cells were labeled by FITC-conjugated cytokeratin antibody (CK 5, 6, 8, and CK 17) prior to flow cytometric cell cycle analysis in 91 specimens of cervical cancer and 73 samples of endometrial cancer. In cervical cancer neither DNA-ploidy nor S-phase fraction were relevant prognostic parameters. But CV of the G(0)G(1)-peak showed prognostic relevance in cervical cancer cells, even in multivariate analysis. This interesting observation, however, seems to have no therapeutic consequence due to the small discrimination capacity of CV. In endometrial carcinoma, gross DNA-aneuploidy (DNA-index > 1.3) and a high percentage of proliferating cells (>75th percentile) were univariate and multivariate highly significant prognostic factors for recurrence-free survival. Especially DNA-aneuploidy (DI>1.3) is one of the most important independent molecular biological prognostic factors. While diagnostic curettage we could identify risk patients even preoperatively by determination of the prognostic factors like histologic tumor type, grading, cervical involvement and DNA-ploidy. Thereby these patients could be treated primarily in an oncologic center. In conclusion, our investigations showed that the determination of DNA-ploidy should be done in endometrial carcinoma. In cervical cancer no clinical significance for determination of DNA-parameters was found.

[Prognostic significance of heat shock proteins 70 and p27 protein in patients with mucoepidermoid carcinoma]

OBJECTIVE

To study the expression of heat shock proteins 70 (HSP70) and p27 in mucoepidermoid carcinoma (MEC) in relation to biological behaviour and prognosis.

METHODS

Immunohistochemical LSAB method was used to evaluate the expression of HSP70 and p27 in 44 MEC. 10 Pleomorphic adenomas (PAs) were used as controls.

RESULTS

The expression of HSP70 was significantly higher in MEC than in PAs, while p27 expression was significantly lower in MEC than in PAs. There was a negative correlation between HSP70 and p27 expression. Compared with clinicopathologic features, the expression of HSP70 was related to histologic grade, clinical stage and tumor size, and p27 expression correlated negatively with histologic grade, clinical stage, tumor size and lymph node metastases. Multivariate analysis revealed that Hsp70 expression was a strong prognostic indicator of MEC.

CONCLUSIONS

HSP70 should be considered an independent prognostic indicator of MEC and p27 might favour prognosis of MEC.

Expression of p53 tumor suppressor gene in adenoid cystic and mucoepidermoid carcinomas of the salivary glands

Seventeen adenoid cystic carcinomas (ACCs) and 27 mucoepidermoid carcinomas (MECs) occurring in the salivary glands were analyzed for p53 tumor suppressor gene alteration (exons 5-8) and protein expression. The cell proliferation activity was also examined by Ki-67 immunohistochemistry. The p53 alterations were detected in three samples (17.6%) of ACC and in four samples (14.8%) of MEC, and were only found in carcinomas arising in the minor salivary glands. The occurrence of the p53 gene alteration is less frequent in ACC and MEC than that in other kinds of tumors, and therefore does not seem to play a critical role in the course of the tumorigenesis in ACC and MEC. All ACC samples arising from the minor salivary glands exhibiting p53 gene alterations showed recurrence/metastasis, thus suggesting a poor outcome of these patients. All ACCs and three out of four MECs samples with p53 gene alterations showed the lowest degree of p53 immunostaining ratio, thus suggesting that no correlation exists between the p53 gene alterations and the p53 immunostaining in these salivary gland carcinomas. No significant relationship was demonstrated between the immunostaining ratio of either p53 or Ki-67 and the morphological growth pattern or patient clinical course in the ACC samples. The p53 immunopositivity in MEC correlated to the histological grade. The Ki-67 immunostaining ratio was also significantly related to the histological grade and the clinical course in MEC.

Oncocytic mucoepidermoid carcinoma of the parotid gland: report of a case with DNA ploidy analysis and review of the literature

A 44-year-old female presented with a painful mass in the left parotid gland. Histologic examination revealed the characteristic picture of oncocytic mucoepidermoid carcinoma (OMEC) composed mainly of sheets of oncocytic cells with uniform nuclei and eosinophilic cytoplasm, focally smaller epidermoid cells surrounding poorly formed glandular spaces, and a few cystic structures lined by well-differentiated mucous cells with intracytoplasmic mucin. Immunohistochemical staining with antimitochondrial antibody showed granular cytoplasmic positivity in oncocytic cells. The resulting histogram for DNA ploidy analysis was of diploid type. OMEC of the parotid gland is a recently described rare neoplasm. Only six cases have been previously reported in the literature. For an accurate approach in the management of patients, OMEC should be considered in the differential diagnosis of oncocytic lesions of the parotid gland, most of which are benign.

Mucoepidermoid carcinoma of salivary glands in children and adolescents: assessment of proliferation markers

Malignant neoplasms represent one-third of all pediatric salivary gland tumors. Mucoepidermoid carcinoma (MEC) composes 51% of malignant tumors and 16% of all salivary gland neoplasms in pediatrics. Prognostic factors in MEC in pediatric patients have not been well defined. Histopathologic features, clinical outcomes and proliferation markers in 26 pediatric patients (median age 11 years; 19F:7M) with salivary gland MECs were evaluated retrospectively. MEC histocytologic grading used a three-tiered system. Proliferation was assessed by determining the percentage of tumor cells immunoreactive for PCNA and Ki-67. Tumor site was 16 parotid, eight submandibular, one base of tongue and one maxillary lip. Median tumor size was 2.5 cm (range 1.5-5 cm). MEC grade was nine low grade (LG), 15 intermediate grade (IG) and two high grade (HG). Metastatic disease and capsular invasion occurred in five cases, while perineural invasion was noted in three cases. Mean percentage of tumor cells immunoreactive for proliferation markers is as follows: PCNA: LG 9%, IG 17%, HG 32%; and Ki-67: LG 7%, IG 12%, HG 26%. Treatment was surgical in 21 cases, and surgery with chemotherapy and radiotherapy in five cases. Two patients with high grade MECs died of disease (21, 44 months). Twenty-four patients had no evidence of disease at a median follow-up of 104 months (range 30-298 months). MECs were second malignancies in two children with prior radiotherapy and chemotherapy for leukemia and histiocytosis. Low and intermediate grade salivary gland MECS in a pediatric population may have a favorable outcome when compared with high grade MECs. Proliferation markers appear to be linked to histocytologic MEC grade and may provide information regarding biologic behavior of salivary gland MECs in children and adolescents.

Primary mucoepidermoid carcinoma and sclerosing mucoepidermoid carcinoma with eosinophilia of the thyroid gland: a report of nine cases

Mucoepidermoid carcinoma is a rare primary thyroid tumor with indolent biologic potential. Two types of tumors have been described under this category: mucoepidermoid carcinoma (MEC) and sclerosing mucoepidermoid carcinoma with eosinophilia (SMECE). The MEC shows both squamous and glandular differentiation in a background of a noninflamed gland, whereas SMECE is characterized by extensive sclerosis, squamous and glandular differentiation, a concomitant inflammatory infiltrate rich in eosinophils, and a background of lymphocytic thyroiditis. We present nine cases of these entities: five MEC and four SMECE. All tumors occurred in women (age 27 to 73 years). Five tumors showed extrathyroidal invasion and multiple lymph node metastases. One case of MEC showed a concomitant tall cell variant of papillary carcinoma with vascular invasion, and two cases showed intimately associated areas of usual papillary carcinoma. One of the latter cases also showed areas of transformation to anaplastic carcinoma. In all cases of SMECE and in only one case of MEC, the uninvolved thyroid tissue showed lymphocytic thyroiditis. Follow-up information was available in four of the nine cases (3 months to 7 years). Two patients with SMECE are alive with no evidence of disease. One patient with MEC and tall cell variant of papillary carcinoma died of disease after 3 months, and the patient with anaplastic carcinoma died after 5 months with lung metastasis. Both MEC and SMECE were positive for cytokeratin and negative for calcitonin. All cases of MEC were positive for thyroglobulin, whereas all cases of SMECE were negative. The immunohistochemical findings suggest that both MEC and SMECE have different histogenesis.

Thyroid sclerosing mucoepidermoid carcinoma with eosinophilia: mimic of Hodgkin disease in nodal metastases

We present the clinical and pathologic findings of a case of sclerosing mucoepidermoid carcinoma with eosinophilia of the thyroid in a 39-year-old woman. This particular case is notable because it initially presented as a cervical lymph node metastasis, and the initial clinical and histologic impression was Hodgkin disease, nodular sclerosis type. Sclerosing mucoepidermoid carcinoma with eosinophilia is a differentiated malignant neoplasm of the thyroid that can be confused with anaplastic carcinoma, medullary carcinoma, squamous cell carcinoma, or, as in this case, Hodgkin disease. A correct diagnosis of sclerosing mucoepidermoid carcinoma with eosinophilia involves awareness of this entity and appropriate immunohistochemical analysis. In this article, we briefly review the literature and stress the histologic and cytologic findings characteristic of sclerosing mucoepidermoid with eosinophilia of the thyroid.

Fine needle aspiration cytology of high grade mucoepidermoid carcinoma of the thyroid. A case report

BACKGROUND

Although mucoepidermoid carcinoma is considered a very rare, low grade thyroid neoplasm, in two patients a very rapid and aggressive outcome occurred. We describe the cytologic, histologic and immunohistochemical findings of a high grade mucoepidermoid carcinoma that evolved into an anaplastic carcinoma.

CASE

A 57-year-old man was admitted with dysphagia, dysphonia and odynophagia. The patient had begun to develop symptoms over the previous two months. Ultrasound and computed tomography revealed diffuse enlargement of the thyroid gland with multiple, bilateral, palpable lymph nodes in the cervical, supraclavicular, paratracheal and retrocaval chains. The patient died four weeks after receiving the first cycle of treatment with adriamycin and cisplatin. The smears were highly cellular, with a background rich in neutrophilic, inflammatory infiltrate and necrotic debris. Two main types of tumor cell were identified: squamoid and mucus secreting. Squamoid cells were polygonal, with well-defined borders and dense cytoplasm. Nuclei varied greatly in shape and size and displayed clumped chromatin and prominent nucleoli. Mucussecreting cells were ring shaped and dispersed among the squamoid cells; they contained a large vacuole, with condensed acid and neutral mucins, that peripherally displaced the nucleus. Small and large clusters of large, polygonal cells with single or multiple bizarre nuclei and less-dense cytoplasm were also present. Histology revealed tumor cells distributed in irregular nests, with necrosis surrounded by a fibrous stroma. The predominant cells were squamoid, but dispersed mucus-secreting cells were frequently seen in the better-differentiated areas. Sparse anaplastic spindle cells were observed adjacent to the squamoid focus. Immunohistochemistry revealed a reaction positive for cytokeratin (AE3/AE1) in tumor nests and negative staining for thyroglobulin and neuroendocrine markers.

CONCLUSION

Although mucoepidermoid carcinoma of the thyroid is a very rare neoplasm, its peculiar cytomorphologic features in fine needle aspiration cytology may contribute to its correct diagnosis.

Proliferative activity as detected by immunostaining with Ki-67 and proliferating cell nuclear antigen in benign and malignant epithelial lesions of the human parotid gland

OBJECTIVE

A retrospective immunohistochemical study of parotid gland lesions was designed to evaluate the diagnostic and prognostic value of the proliferating cell nuclear antigen (PCNA) and Ki-67 with monoclonal antibodies PC 10 and MIB-1, respectively.

STUDY DESIGN

Tissue samples comprised normal parotid gland (N, n = 10), chronic sialadenitis (CS, n = 8), Warthin's tumor (W, n = 10), benign pleomorphic adenoma (BPA, n = 8), mucoepidermoid carcinoma (MEC, n = 13), carcinoma in pleomorphic adenoma (CPA, n = 8) and adenoid cystic carcinoma (ACC, n = 12). The morphometric parameters for PCNA and MIB-1 comprised the PI and MI labelling indices (the numerical percentage of positive nuclei), NAP and NAM (the numerical density of positive nuclei), and NPI and NMI (volume corrected index).

RESULTS

The values of MIB-1 parameters increased progressively in benign lesions in comparison with the N group and in malignant neoplasms in comparison with nonneoplastic groups and benign lesions. Values for all parameters in BPA were significantly lower than those in malignant groups. Spearman rank correlation analysis showed a highly positive correlation between the morphometric parameters and severity of the lesions. The mean values of MI and NMI were significantly higher in patients who died of the malignant tumors than in those who survived. The same quantitative parameters for PCNA did not differ significantly from those obtained for MIB-1 and showed similar trends.

CONCLUSION

PCNA and MIB-1 indices are reliable markers for discriminating between benign and malignant tumors of the parotid gland, and the parameters PI, MI, NPI and NMI may have prognostic applications.

Oncocytic and oncocytoid tumors of the salivary glands

Primary pink cell tumors of the salivary glands constitute a heterogeneous group of benign and malignant lesions characterized by tumor cells with abundant eosinophilic cytoplasm. These tumors are composed predominantly of oncocytic, epidermoid, or myoepithelial cells. Tumors with a significant oncocytic component include Warthin's tumor, oncocytoma, and oncocytic carcinoma. An epidermoid component can be seen as a metaplastic change or as a true cellular constituent of a mucoepidermoid carcinoma. Myoepithelial cells may have an epithelioid character and as a consequence may impart a pink cell appearance in pleomorphic adenoma, myoepithelioma, and myoepithelial carcinoma. Usually most of these tumors are fairly distinct morphologically and do not present diagnostic dilemmas. In select circumstances, especially when dealing with a limited tissue sample, a systematic approach with an appropriate immunohistochemical panel should be used in order to arrive at a correct diagnosis. Accurate assessment is the key in the subsequent management and follow-up of these patients.

[Bcl-2 gene protein expression in salivary gland tumors]

BACKGROUND

Salivary gland tumors have heterogeneous pathological features. Oncogene Bcl-2 product expression inhibits apoptosis and therefore is important for tumor proliferation.

AIM

To assess the immunohistochemical gene Bcl-2 protein expression in salivary gland tumors.

MATERIAL AND METHODS

Twenty seven salivary gland tumors were selected from the archives of the Pathology Department of Temuco Regional Hospital. There were 20 pleiomorphic adenomas, 4 cystic adenoid carcinomas and three mucoepidermoid carcinomas. Immunohistochemical gene Bcl-2 protein expression was determined in paraffin included pathological slices.

RESULTS

All pleiomorphic adenomas expressed the protein, specially in tubulo ductal structures, solid and trabecular areas. All cystic adenoid carcinomas expressed the protein in myoepithelial cells. Two mucoepidermoid carcinomas were positive, only in the epidermoid areas.

CONCLUSIONS

immunohistochemical gene Bcl-2 protein was expressed in virtually all benign and malignant salivary gland tumors. This observation suggest an important role of this protein in the development of these tumors.

Hyaluronan and CD44 expression in minor salivary gland tumors

OBJECTIVES

Hyaluronan (HA) and CD44 are most likely associated with tumor invasion and metastasis. Malignancies with different degrees of aggressiveness may express different levels and patterns of HA and CD44. The aim of this project was to examine the distribution of HA and CD44 in minor salivary gland tumors to determine if staining could be correlated with biologic behavior or tumor type.

MATERIALS AND METHODS

Biotinylated hyaluronan binding protein as a probe for HA and monoclonal antibodies specific for CD44 were used to stain classic examples of the five most commonly encountered minor salivary gland tumors: monomorphic adenomas, pleomorphic adenomas, polymorphous low grade adenocarcinomas, mucoepidermoid carcinomas, and adenoid cystic carcinomas.

RESULTS

Tumor cells of monomorphic adenomas were negative for both HA and CD44, and tumor capsules were intensely HA-positive. Pleomorphic adenomas exhibited HA and CD44 positivity in both mesenchymal and epithelial components, and HA in capsular tissues. All malignant salivary gland tumors expressed similar intense HA in tumor stroma. HA staining was more intense in stroma than in parenchymal cells. Tumor cells of most adenoid cystic carcinomas were HA-positive, while most polymorphous low grade adenocarcinomas were HA-negative. HA was uniformly distributed throughout supporting stroma of high and low grade malignancies, except for two polymorphous low grade adenocarcinomas (PLGAs) in which HA was more intense at the invading edge of the tumors. CD44 expression was seen only in tumor cells (not stroma) of malignancies, and was of similar intensity in both low and high grade tumors.

CONCLUSIONS

Differences in the expression of HA and CD44 among different types of salivary gland tumors were noted. These findings, however, could not be correlated with known biologic behaviors of the tumor groups studied. Immunohistochemical staining of salivary gland tumors for HA and CD44 may be useful in separating monomorphic adenoma, polymorphous low grade adenocarcinoma and adenoid cystic carcinoma, lesions that may be difficult to distinguish with routine light microscopy.

Naturally occurring mucoepidermoid carcinoma in the submandibular salivary gland of two mice

Mucoepidermoid carcinomas in two mice were investigated histologically, immunohistochemically and ultrastructurally. The neoplastic cells showed divergent differentiation into periodic acid-Schiff-positive mucous cells, keratin-positive squamous cells, and cells with both mucous granules and sheaves of tonofilaments. Gland formation and keratinization were not observed. At the periphery of tumour cell nests, some cells were immunolabelled for smooth muscle actin or contained concentrated thin filaments, and these observations were interpreted to indicate that murine mucoepidermoid carcinomas are associated with both myoepithelium and duct epithelium.

Mucoepidermoid carcinoma of the salivary gland--a clinico-pathologic and immunohistochemical study for c-erbB-2 oncoprotein

Twenty-five cases of mucoepidermoid carcinoma of the salivary glands were studied with respect to clinico-pathologic features, prognostic factors, and c-erbB-2 oncoprotein expression. Fourteen cases were located in parotid glands, 2 in submandibular glands and 9 in minor salivary glands. Fourteen patients were confirmed to have local recurrences, 6 patients manifested systemic metastases, and 10 patients died of the disease. They were histologically graded as I in 5, II in 12 and III in 8 cases respectively, and the histologic grade was significantly correlated with disease-free interval and overall survival of the patients. c-erbB-2 overexpression was observed in 9 cases (36%), with a trend to be associated with the higher grade, but was not evaluated as a significant survival-related factor in this series. Larger size and major gland location of the tumors were correlated with more frequent regional lymph node metastases. The present study showed that c-erbB-2 overexpression was not uncommonly present in mucoepidermoid carcinoma of the salivary glands, especially of higher grade, and the histologic grade was the most important and handy prognostic indicator.

[Determination of DNA content in salivary gland tumors]

BACKGROUND

DNA content determination is a useful tool in the characterization of different malignant tumors.

AIM

To measure DNA content in cells of salivary gland tumors as adjunct to histological diagnosis, correlating morphologic and biological features of these tumors.

MATERIAL AND METHODS

From the archives of the Pathology service of a general hospital, 21 salivary gland tumors, 15 pleomorphic adenomas, 3 mucoepidermoid carcinomas and 3 cystic adenoid carcinomas were selected. DNA content was determined in the histological samples using a flow cytometric DNA analysis.

RESULTS

All pleomorphic adenomas had a normal or diploid DNA content. Fifty percent of malignant tumors had an aneuploid DNA content (1 mucoepidermoid carcinoma and 2 cystic adenoid carcinomas).

CONCLUSIONS

DNA determination may help in the histological diagnosis of salivary gland tumors. The presence of aneuploidy suggests malignity.

Sclerosing mucoepidermoid carcinoma with eosinophilia of the thyroid: report of two patients, one with distant metastasis, and review of the literature

Sclerosing mucoepidermoid carcinoma with eosinophilia (SMECE) is a recently recognized malignant neoplasm of the thyroid gland. Two additional cases of this condition which occurred in a 70-year-old woman and a 69-year-old woman are presented. The case of the 70-year-old woman (patient 1) is the first report of distant metastasis, besides lymph node metastasis, for this type of tumor. The patient initially presented with a thyroid mass, and the thyroid gland with surrounding cervical lymph nodes was removed. Because of focal keratin "pearl" formation, the tumor was misinterpreted as a metastatic squamous cell carcinoma to the thyroid. Approximately 4 years later, the patient developed a left supraclavicular mass and lung densities. A pathological fracture of the right humeral head followed, and the left supraclavicular mass recurred along with newly developed subcutaneous nodules on the chest wall and arm. Open lung and bone biopsies revealed metastatic SMECE, which was morphologically identical to that of the thyroid mass. The 69-year-old woman (patient 2) had, in 1983, undergone thyroidectomy with left radical neck dissection; this had been diagnosed as follicular carcinoma of the thyroid with lymph node involvement. After multiple isolated lymph nodes metastases, the patient developed locally extensive, recurrent tumor that showed microscopic features of SMECE. Review of the previous thyroid tumor and lymph nodes revealed the same type of histology. To our knowledge, only a single report containing eight cases of this distinctive carcinoma of the thyroid has been published. Herein we describe characteristic morphological features of two additional cases of this rare malignancy, one with distant metastasis, and we review the related literature.

Expression and mutations of p53 in salivary gland tumours

A series of 219 salivary gland tumours (103 carcinomas and 116 benign tumours) were analysed for p53 protein expression using immunohistochemistry, and for mutations in p53 gene using non-radioactive single strand conformation polymorphism (SSCP). p53 expression was present in 36% (42/116) of the benign tumours and in 54% (56/103) of the carcinomas. The highest prevalence of p53 expression was found in adenoid cystic carcinomas (69%), followed by mucoepidermoid carcinomas (67%). Of the benign tumours, pleomorphic adenomas showed the highest prevalence of p53 positivity (41%). In malignant tumours, expression of p53 bore no correlation to local recurrence, metastatic disease or survival of the patients. Exons 5 through 9 were analysed and four mutations were found in 20 cases of p53-immunopositive tumours and two in 20 p53-negative tumours. Each of the exons 5, 6 and 8/9 had two mutations, whereas no mutations were detected in exon 7.

Papillary carcinoma of the thyroid with mucoepidermoid differentiation

A case of papillary carcinoma of the thyroid with mucoepidermoid differentiation is reported. There have been different hypotheses of the histogenesis of this tumor, one of which attributes the origin of the tumor to the ultimobranchial body, mainly because of the presence of neuroendocrine markers. In our case, no neuroendocrine immunohistochemical markers were demonstrated, but a progressive transition between follicular cells and mucinous cells with gradual loss of thyroglobulin immunoreactivity and acquisition of polyclonal carcinoembryonic antigen reactivity was noted. Therefore, we propose that mucoepidermoid carcinoma may be a simple metaplastic transformation of a papillary carcinoma, because the thyroid glandular epithelium, which is of endodermal origin, is capable of differentiating easily into squamous, mucus-secreting, or even polypeptide-secreting epithelium.

Mast cell tryptase is a mitogen for epithelial cells. Stimulation of IL-8 production and intercellular adhesion molecule-1 expression

Tryptase, a protease unique to the mast cell secretory granule, is released in substantial quantities into the respiratory tract of patients with inflammatory disease of the airways. We have investigated the potential of tryptase to act as a mitogen for bronchial epithelial cells and to stimulate release of IL-8 and expression of ICAM-1. Tryptase was isolated from extracts of human lung tissue using ammonium sulphate precipitation, octyl agarose, and heparin agarose chromatography. Purified tryptase stimulated DNA synthesis in the human epithelial cell line H292, as measured by [3H] thymidine incorporation. Maximal growth was observed after 24 h using 25 mU/ml of tryptase (where 1 micron is defined as that which can hydrolyze 1 mumol of the peptide substrate N-alpha-benzoyl-DL-arginine p-nitroanilide hydrochloride per minute at 25 degrees C), a concentration that is likely to be achieved in vivo. Inhibitors of tryptase activity, including leupeptin and benzamidine hydrochloride, significantly decreased tryptase-induced stimulation of DNA synthesis, indicating the requirement for an active catalytic site. Tryptase stimulated a catalytic site-dependent release of IL-8 from epithelial cells after 24 h, and this was associated with up-regulation of ICAM-1 expression, as revealed by FACS analysis. Tryptase may play a critical role in epithelial repair and in the recruitment of granulocytes following mast cell activation.

Amplification and overexpression of HER-2/neu in carcinomas of the salivary gland: correlation with poor prognosis

There are few reliable prognostic markers of biological aggressiveness for head and neck carcinomas in general. For salivary gland carcinomas, anatomic location, tumor size, histological grade, and extent of disease involvement are considered to be clinically important risk factors for recurrent disease. Molecular genetic alterations in salivary gland carcinomas have not been characterized, and tumor cell proteins have not been shown to be prognostically significant. Here a cohort of mucoepidermoid carcinomas of the major (parotid and submandibular) salivary glands are analyzed for a molecular genetic alteration, HER-2/neu gene amplification, and gene amplification and expression results are compared with long-term clinical follow-up information. Archival tissues resected from 58 patients with mucoepidermoid carcinoma of salivary glands were evaluated for HER-2/neu gene amplification by fluorescence in situ hybridization and for gene expression by immunohistochemistry in a blinded fashion. Clinical follow-up information was compared with the results of these analyses to determine whether there were significant associations. Overexpression, identified as membrane immunostaining by immunohistochemistry, was observed in 22 of 58 (38%) mucoepidermoid carcinomas. Gene amplification, characterized by fluorescence in situ hybridization, was observed in 12 (21%) cases. Eleven of the 12 cases with gene amplification were also immunostained for HER-2/neu. Both gene amplification (P = 0.0001, P < 0.0001) and immunostaining (P < 0.0001, P < 0.0001) were correlated with shorter disease-free interval and poorer overall patient survival, respectively. Multivariate analysis showed that HER-2/neu immunostaining and amplification were markers of poor prognosis independent of histopathological grade, tumor size, and involvement of regional lymph nodes. HER-2/neu is amplified and/or overexpressed in approximately one-third of mucoepidermoid carcinomas of salivary glands. Amplification and/or overexpression appears to be an independent marker of poor prognosis in mucoepidermoid carcinomas of the salivary glands as it is in carcinomas of the breast, ovary, and endometrium.

Low grade mucoepidermoid carcinoma ex pleomorphic adenoma. A diagnostic problem in fine needle aspiration biopsy

We report a case of low grade mucoepidermoid carcinoma arising in a pleomorphic adenoma (ex pleomorphic adenoma) in the parotid salivary gland of a 32-year-old woman. Fine needle aspiration biopsy showed the typical biphasic pattern of pleomorphic adenoma: groups of benign-appearing epithelial cells and chondromyxoid stroma. In addition, features of low grade mucoepidermoid carcinoma were identified retrospectively, consisting of background mucin and rare mucin-containing cells. This case illustrates that the presence of background mucin and mucin-containing cells in an otherwise usual pleomorphic adenoma may indicate the presence of a well-differentiated mucoepidermoid carcinoma. In cases such as this, a definitive diagnosis should be postponed until the lesion is examined histologically.