Pleural metastasis from auricular melanoma: A brief report

Primary auricular melanoma is rarely reported. Approximately, it accounts for 1% to 4% of all cutaneous melanoma. Early literature suggested that melanoma of the ear is more aggressive than other melanomas, with a propensity for spreading to both regional lymph nodes and distant sites. Here, we present a case of cytological pleural metastasis from auricular melanoma in a 43-year-old woman. Immunohistochemical staining showed that the tumors cells were positive for S-100 protein and Melan-A. The mutation of the v-raf murine sarcoma viral oncogene homolog B (BRAF)V600E was demonstrated on Sanger sequencing. To our knowledge, this is the first report describing the cytomorphology of metastatic auricular melanoma in pleural effusion.

Expression of MMP-3, MMP-13, TIMP-2 and TIMP-3 in the VX2 carcinoma of the New Zealand white rabbit

BACKGROUND

Squamous cell carcinomas of the head and neck region (HNSCC) are among the most common malignancies in this area. The VX2 carcinoma of the New Zealand white rabbit metastasizes lymphatically as is the case in HNSCC and therefore, potentially, could be used as a model for HNSCC. Since the family of matrix-metalloproteinases (MMPs) is involved in the process of HNSCC invasion, the aim of this study was to investigate the expression level of MMPs and their specific inhibitors (TIMPs) in the VX2 carcinoma to evaluate if they also play a role in VX2 tumor invasion as observed in human HNSCC.

MATERIALS AND METHODS

The VX2 carcinoma was generated by tumor implantation in the rabbit's ear as previously described. Western blots were performed under standard conditions, utilizing antibodies against MMP-3, MMP-13, TIMP-2 and TIMP-3. Immunohistochemical staining was performed with the ABC-complex method.

RESULTS

A positive immunohistochemical signal could be detected for MMP-3, TIMP-2 and TIMP-3 with no significant signal for MMP-13. In the Western blots immunoreactive bands could be observed for MMP-3, MMP-13, TIMP-2 and TIMP-3.

CONCLUSION

MMP-3, MMP-13, TIMP-2 and TIMP-3 were found to be expressed in VX2 carcinomas of the New Zealand white rabbits. The VX2 carcinoma therefore resembles HNSCC tumors not only in its metastatic behavior, but also regarding the expression of MMPs and TIMPs, which are the probable keyplayers during the event of invasion. These observations further underline the significance of the VX2 carcinoma as a model tumor of human HNSCC.

Telomerase activity, telomere length, and apoptosis: a comparison between acquired cholesteatoma and squamous cell carcinoma

BACKGROUND

Cholesteatoma disease is characterized by accumulation of keratinizing epithelium. Several molecular markers of tumor formation have been found in cholesteatoma (e.g. upregulation of matrix metalloproteinases, c and activation of angiogenesis). Other molecular findings clearly distinguish between cholesteatoma and malignant tumors (e.g., lack of chromosomal instability, intact checkpoint responses). To further distinguish the molecular mechanisms in cholesteatoma from malignant tumors, the authors determined telomerase activity and telomere length in both tissue types.

METHODS

To evaluate the role of telomerase activation and telomere length in cholesteatoma, 29 cholesteatoma samples and 9 squamous cell carcinomas were analyzed for telomerase activity and telomere length. In addition, the rate of apoptosis was determined in both groups, using the TdT-mediated dUTP nick end labeling technique.

RESULTS

As previously described, a high proportion of squamous cell carcinoma exhibited telomerase activity (6/9, 66%). By contrast, a significantly lower rate of telomerase activity was found in cholesteatoma samples (1/29, 3.4%, p = 0.0002). Despite the differences in telomerase activity, the telomere length was similar in cholesteatoma (mean length 7.43 kb) and in squamous cell carcinoma (mean length 7.99 kb; difference not significant, p = 0.1364). The low rate of telomerase activity in cholesteatoma was accompanied by significantly higher rates of apoptosis in cholesteatoma (mean 30%) compared with squamous cell carcinoma tissue (mean 3%, p = 0.0031).

CONCLUSIONS

Taken together, these data show that telomerase activation is a rare event in cholesteatoma and that the absence of telomerase activity is accompanied by high rates of apoptosis in cholesteatoma. It is proposed that the absence of telomerase limits the proliferative capacity of cholesteatoma by induction of apoptosis, whereas the presence of telomerase allows immortal growth of squamous cell carcinoma.

[Expression of matrix metalloproteinasa-2,9 in cholesteatoma and middle ear cancer]

OBJECTIVE

To study various expressions and roles of MMP-2, 9 in cholesteatoma and middle ear cancer.

METHODS

MMP-2 and MMP-9 were detected with immunohistochemical methods using monoclonal antibody in 36 cholesteatomas, 10 CAMS and 16 middle ear cancer.

RESULTS

The stain in cholesteatoma was stronger than that in CAMS and NAMS. Expressions of MMP-2, 9 were seen in all layers of the epithelium in CA and the stain was strongest in basement membrane. The positive rates of stain was 83% and 50% in CA and CAMS respectively. There was weak stain in 2 NAMS. In middle ear cancer, the expression rates of MMP-9 and MMP-2 were 50% (8/16) and 56.25% (9/16) respectively. The expression level was correlated with tumor differentiation and its clinical stage. Expressions of MMP-2 and MMP-9 were closely related in cholesteatoma. There was no relationship between expressions of MMP-2 and MMP-9 in middle ear cancer.

CONCLUSION

Cholesteatoma has a similar feature with middle ear cancer in invading surrounding of surround bone matrix. The disorder between MMPs and its inhibitor was one of reasons for bone absorption of cholesteatoma and middle ear cancer.

Middle ear adenomatous tumor with a predominant neuroendocrine component

A primary adenomatous tumor of the middle ear was examined by light microscopy, ultrastructural and immunohistochemical techniques. In support of its extensive neuroendocrine differentiation, was the diffuse detection of neuron-specific enolase (NSE) and positive immunoreaction with antibodies to chromogranin and synaptophysin. The great majority of tumor cells contained neurosecretory granules and intraluminal mucin production could be focally detected. These characteristics confirm the diagnosis of a middle ear adenomatous tumor (MEAT) of a biphasic nature and with a prominent neuroendocrine component.

Aural polypi: a histopathological and histochemical study

Aural polypi associated with chronic suppurative otitis media have been studied histopathologically and histochemically in 20 patients. The polypi consist of an edematous connective tissue stroma infiltrated by chronic inflammatory cells and numerous blood vessels. The surface is covered by intact stratified squamous epithelium. The histochemical study revealed altered permeability of the blood vessels which seem to be the main pathological background for polyp formation. An enhanced phagocytic activity and increased metabolic activity were found in the epithelium in the chronic inflammatory cells. No glandular activity was found in the polypi.