Primary lung cancer vs metastatic breast cancer: a probabilistic approach

Role of immunohistochemistry markers in neoplastic lung lesions

Objectives

The objective of the evaluate was to study and determine the usefulness of immunohistochemistry (IHC) staining in neoplastic lung lesions.

Materials and Methods

We evaluated seven IHC stains in fifty lung cancers that included adenocarcinoma (AC), squamous cell carcinoma (SCC), small cell carcinoma, and carcinoid tumors.

Results

P63 was expressed in all the cases of SCCs and thyroid transcription factor-1 (TTF-1) was expressed in all cases of ACs. CK 5/6 was expressed in 77.77% of SCCs and CK 7 was expressed in 92.59% of ACs. Synaptophysin and chromogranin-A were expressed in 100% of neuroendocrine (NE) carcinomas.

Conclusion

P63 and TTF-1 are sensitive markers for SCCs and ACs. Synaptophysin and Chromogranin-A are sensitive markers for NE carcinomas.

Differential expression of various clones of estrogen receptor in cell block preparation of lung adenocarcinoma

BACKGROUND

Women treated for breast cancer are at increased risk of developing pulmonary nodules which could represent new primary lung carcinomas or metastatic breast carcinoma. The FNA biopsy is frequently the first diagnostic choice in determining the primary site of the tumor. Estrogen receptor (ER) positivity in diagnostic tissue is generally used to favor breast over lung primary. However, the recent studies have shown a wide range of ER antibody cross reactivity with lung adenocarcinoma. We studied the frequency of ER expression in cytology samples of lung adenocarcinoma using antibodies to three different ER clones.

METHODS

Cytology cell block preparations, including 22 lung FNAs and 19 malignant pleural effusions (PE) from 41 patients, with clinically documented primary lung adenocarcinomas were selected for this study. All cases were stained with monoclonal antibodies to ER clones 6F11 and 1D5. Twenty nine cases with remaining available material (15 FNA and 14 PE) were stained with a third antibody to ER clone SP1. The extent of ER nuclear staining was scored as 3+ (50%-100% of tumor cells), 2+ (11%-49%), and 1+ (≤10%).

RESULTS

Positivity for ER-6F11 clone was present in 4 of 22 lung FNAs (18.2%, 2+ staining). Two of the four 6F11 positive FNAs also co-expressed ER-1D5 (9.1%, 2+ staining). No immunoreactivity was observed for ER clones 6F11 and 1D5 in all 19 malignant PEs. In addition, none of the remaining 15 FNAs and 14 PEs showed immunoreactivity for ER-SP1 clone.

CONCLUSIONS

A small subset of pulmonary adenocarcinomas shows immunoreactivity for ER clones 6F11 and 1D5 in FNA samples (18.2% and 9.1%, respectively). The absence of immunoreactivity for ER-SP1 clone indicates higher specificity of this clone in non-breast tissue. The differential diagnostic value of all ER clones in malignant PEs appears to be secure. Larger studies are necessary to validate this observation.

Choroidal metastases 34 years after remission of breast cancer

PURPOSE

To report a case of choroidal metastases from breast carcinoma occurring after a remission period of 34 years.

METHODS

Case report and literature review.

RESULTS

A 77-year-old woman who presented with blurry vision was found to have choroidal metastatic lesions in both her eyes. She had a remote history of breast cancer (status post mastectomy) 34 years ago. A metastatic workup was performed that revealed the presence of widespread metastatic lesions in the lungs, liver, and bones.

CONCLUSION

Although the median time period for the detection of choroidal metastases is 3 years after the diagnosis of the primary malignancy, choroidal metastases can present till 34 years later as in our case (the longest time interval reported in the literature).

A pathologist-in-the-loop IHC antibody test selection using the entropy-based probabilistic method

Background:

Immunohistochemistry (IHC) is an important tool to identify and quantify expression of certain proteins (antigens) to gain insights into the molecular processes in a diseased tissue. However, it is a challenge for pathologists to remember the discriminative characteristics of the growing number of such antigens across multiple diseases. The complexity of their expression patterns, fueled by continuous discoveries in molecular pathology, gives rise to a combinatorial explosion that places an unprecedented burden on a practicing pathologist and therefore increases cost and variability of IHC studies.

Materials and Methods:

To tackle these issues, we have developed antibody test optimized selection method, a novel informatics tool to help pathologists in improving the IHC antibody selection process. The method uses extensions of Shannon's information entropies and Bayesian probabilities to dynamically build an efficient diagnostic tree.

Results:

A comparative analysis of our method with the expert and World Health Organization classification guidelines showed that the proposed method brings threefold reduction in number of antibody tests required to reach a diagnostic conclusion.

Conclusion:

The developed method can significantly streamline the antibody test selection process, decrease associated costs and reduce inter- and intrapathologist variability in IHC decision-making.

Survivin is a novel target of CD44-promoted breast tumor invasion

The hyaluronan (HA) receptor CD44 plays an essential role in cell-cell or cell-extracellular matrix communications and is a bioactive signal transmitter. Although a number of studies have described the function of CD44 in breast cancer (BC) metastasis, the underlying mechanisms have yet to be determined. By using a validated tetracycline-off-regulated CD44 expression system in the MCF-7 cell line combined with microarray analysis, we identified survivin (SVV) as a potential downstream transcriptional target of CD44. To test the hypothesis that SVV underpins CD44-promoted BC cell invasion, we combined molecular and pharmacologic approaches and showed that CD44 induction increased SVV expression levels, which in turn promotes BC cell invasion. Further, clinical analysis of breast tissue samples showed that SVV expression patterns paralleled those of the standard form of CD44 during breast tumor progression. More interestingly, we identified the PI3K/E2F1 pathway as a potential molecular link between HA/CD44 activation and SVV transcription. In addition to identifying SVV as a target for HA/CD44 signaling, this investigation provides a better understanding of the molecular mechanisms that underpin the novel function of SVV in breast cancer metastasis.

Pulmonary Neuroendocrine Tumors

Pulmonary neuroendocrine tumors are frequently encountered as small biopsy and resection specimens. Although the World Health Organization (WHO) classification is used as a diagnostic framework globally and in daily practice, it is not without controversy and practical difficulties. The WHO criteria for pulmonary neuroendocrine tumors are reviewed with the recognition that the definitions are based on resected specimens, which are often not the usual clinical circumstances. A practical approach is emphasized, and the differential diagnosis is discussed with particular attention to the context in which diagnostic difficulties are most frequently encountered, such as small biopsies and frozen sections.