Faculty Bibliography

Myelolipomas are benign tumors, histologically consisting of an admixture of mature adipose tissue and normal hematopoietic elements. It is most commonly found in the adrenal glands. Extra-adrenal myelolipomas are rare. Due to the rarity of this entity, exposure to and awareness of the cytological characteristics are limited. We report a case of intra-abdominal extra-adrenal myelolipoma diagnosed by fine needle aspiration (FNA) in a 67-year-old female, and review of relevant English literature. Knowledge of the cytological features of myelolipoma will avoid mistaking this benign tumor as malignant.

As a review for the 20th anniversary of publishing the antigen retrieval (AR) technique in this journal, the authors intend briefly to summarize developments in AR-immunohistochemistry (IHC)-based research and diagnostics, with particular emphasis on current challenges and future research directions. Over the past 20 years, the efforts of many different investigators have coalesced in extending the AR approach to all areas of anatomic pathology diagnosis and research and further have led to AR-based protein extraction techniques and tissue-based proteomics. As a result, formalin-fixed paraffin-embedded (FFPE) archival tissue collections are now seen as a literal treasure of materials for clinical and translational research to an extent unimaginable just two decades ago. Further research in AR-IHC is likely to focus on tissue proteomics, developing a more efficient protocol for protein extraction from FFPE tissue based on the AR principle, and combining the proteomics approach with AR-IHC to establish a practical, sophisticated platform for identifying and using biomarkers in personalized medicine

Granular cell astrocytoma (GCA) is a rare type of malignant brain tumor with distinct morphologic features and aggressive clinical behavior. Almost all GCAs occur in the cerebral hemispheres. It is characterized by a prominent component of bland-looking granular cells. The tumor cells are usually positive for glial fibrillary acidic protein, S100, CD68, and epithelial membrane antigen. The most important differential diagnoses include a number of reactive lesions such as cerebral infarction, multiple sclerosis, and progressive multifocal leukoencephalopathy. Electron microscopic study reveals that the granules of GCA correspond to an increased number of intracytoplasmic lysosomes. The histogenesis of GCA is still unclear, but most people believe it originates from astrocytes. Loss of 9p and 10q were identified in almost all cases of GCA, but they are not specific for this tumor. Surgical excision plus postoperative chemotherapy or radiotherapy is the choice for most patients with GCA.

OBJECTIVE:To investigate the role of potential downstream targets of HER-2/neu, including the cell-cycle regulator p27, proliferation-associated protein Ki-67, apoptosis inhibitor Bcl-2, and signal-transduction molecule Akt (which is associated with cell survival), as the development of androgen-independent prostate cancer (AIPC) in patients who are initially responsive to androgen-ablation therapy (AAT) is a significant clinical problem. PATIENTS AND METHODS/METHODS:Earlier studies showed that high levels of HER-2/neu tyrosine kinase receptor expression as assessed by immunohistochemistry were significantly associated with the development of AIPC, and we hypothesised that HER-2/neu overexpression provides an alternative proliferative stimulus upon androgen depletion. We established a unique clinical model system, comprising patients who received no AAT, or who had preoperative AAT, or those with advanced tumours resistant to AAT. To test our hypothesis in vitro, we stably transfected full-length HER-2/neu cDNA in androgen-responsive LNCaP cells and examined the effects of HER-2/neu overexpression on cell proliferation, apoptosis, androgen-receptor activation, and Akt phosphorylation upon androgen deprivation by using immunohistochemistry and Western blot technique. RESULTS:p27 expression was initially induced on exposure to AAT, and significantly decreased in AIPC (P < 0.001). There was also a significant increase in the Ki-67 index in AIPC (P = 0.001). Elevated Bcl-2 expression was closely associated with AAT (P = 0.002), suggesting that Bcl-2 expression is induced on initial exposure to AAT. Further, Bcl-2 expression was highest in hormone-resistant cancers (P < 0.001). Using the HER-2/neu transfected cell-line model, we confirmed the mechanistic basis of the clinical observations which elucidate the pathway leading to HER-2/neu-mediated androgen independence. On androgen deprivation, the HER-2/neu transfected cells had higher proliferation rates, lower G1 arrest, inhibited p27 up-regulation, a lower apoptotic index, and higher Bcl-2, prostate-specific antigen and phosphorylated Akt expression than the mock-transfected LNCaP cells. CONCLUSION/CONCLUSIONS:This study suggests that prostate cancer cells undergo a series of coordinated changes after exposure to AAT, which eventually result in the development of androgen independence. Further, in support of previous results, it appears that a major factor in this process is the induction of HER-2/neu overexpression, which occurs after initial exposure to AAT. HER-2/neu may contribute to the development of androgen independence through: (i) maintaining cell proliferation; (ii) inhibiting apoptosis; and/or (iii) inducing AR activation in a ligand-independent fashion. These effects may be mediated, at least in part, through activation of the PI3K/Akt pathway.

During the course of diagnostic surgical pathology, pathologists have established a large collection of formalin-fixed, paraffin-embedded tissues that form invaluable resources for translational studies of cancer and a variety of other diseases. Accessibility of macromolecules in the fixed tissue specimens is a critical issue as exemplified by heat-induced antigen retrieval (AR) immunohistochemical (IHC) staining. On the basis of observations that heating may also enhance in situ hybridization (ISH) and the similarity of formalin-induced chemical modifications that occur in protein and in DNA, we designed a study to examine the efficiency of DNA extraction from archival formalin-fixed, paraffin-embedded tissues using an adaptation of the basic principles of the AR technique, i.e., heating the tissue under the influence of different pH values. Archival paraffin blocks of lymph nodes, tonsil, and colon were randomly selected. Each paraffin block was prepared in 34 microtubes. For each paraffin block, one tube was used as a control sample, using a non-heating DNA extraction protocol. The other 33 tubes were tested using a heating protocol under 11 variable pH values (pH 2 to 12) under three different heating conditions (80, 100, and 120C). Evaluation of the results of DNA extraction was carried out by measuring yields by photometry and PCR amplification, as well as kinetic thermocycling (KTC)-PCR methods. In general, lower pH (acid) solutions gave inferior results to solutions at higher pH (alkaline). Heating tissues at a higher temperature and at pH 6-9 gave higher yields of DNA. There appeared to be a peak in terms of highest efficiency of extracted DNA at around pH 9. The average ratios 260:280 of extracted DNA also showed better values for samples heated at 120C. PCR products of three primers showed satisfactory results for DNA extracted from archival paraffin-embedded tissues by heating protocols at pH 6-12, with results that were comparable to the control sample subjected to the standard non-heating, enzymatic DNA extraction method. This study is the first to document the use of heating at an alkaline pH for DNA extraction from archival formalin-fixed, paraffin-embedded tissues, a recommendation based on the principles of AR for protein IHC. These findings may lead to a more effective protocol for DNA extraction from archival paraffin-embedded tissues and may also provide enhanced understanding of changes that occur during formalin-induced modification of nucleic acids.

PURPOSE/OBJECTIVE:HER-2/neu is a proto-oncogene that encodes a transmembrane receptor belonging to the family of epidermal growth factor receptors. Increasing evidences indicates that HER-2/neu may contribute to hormone resistance in prostate cancer. We investigated HER-2/neu expression in primary, androgen dependent and advanced androgen independent prostate cancer, and its potential value as a marker of disease progression. MATERIALS AND METHODS/METHODS:Immunohistochemical testing was performed to investigate HER-2/neu expression in 81 patients with prostate cancer, including 31 with pathological stage C disease treated with radical prostatectomy without preoperative androgen ablation therapy (untreated group), 30 with pathological stage C disease treated before surgery with androgen ablation therapy (treated group) and 20 with advanced androgen independent prostate cancer (androgen independent group). Tumors were classified based on the percent of tumor cells showing HER-2/neu membrane immunoreactivity as low (50% or less) and high (50% or greater) expression. RESULTS:Of the 31 prostate tumors in the untreated group 9 (29%) showed high HER-2/neu expression versus 15 of 30 (50%) in the treated and 17 of 20 (85%) in the androgen independent groups. The difference in HER-2/neu expression was significant in the untreated and androgen independent (p <0.001) and in the treated and androgen independent (p = 0.016) groups. There was a significant association of Gleason score with HER-2/neu expression in the untreated group (p = 0.038) but not in the treated group. No association was found of tumor substage with HER-2/neu expression. In the untreated group patients with tumors showing high HER-2/neu expression had a decreased survival rate (p = 0.044). CONCLUSIONS:High HER-2/neu expression is highly associated with exposure to hormone therapy and androgen independence. It may contribute to androgen independence in prostate cancer and identify patients with prostate cancer more likely to have disease progression, particularly those not exposed to previous hormone therapy.