Michael D. Linden

Determining prognosis of clinically localized prostate cancer by immunohistochemical detection of mutant p53

OBJECTIVES Mutations of the p53 tumor suppressor gene can result in unregulated cellular growth and have been implicated in numerous malignancies. The objective of this study was to determine whether the detection of mutant p53 by immunohistochemical staining is predictive of progression in clinically localized adenocarcinoma of the prostate. METHODS Immunohistochemical staining for mutant p53 was performed on 40 formalin-fixed radical prostatectomy specimens. Benign glands in the sections served as controls. Immunoreactivity (IR) was categorized semi-quantitatively from 0 to 4+ (0 = no IR, 1+ = 1 % to 10%, 2+ = 11% to 40%, 3+ = 41 % to 70%, 4+ = 71 % to 100%). Results were then compared to Gleason score, Stage (T2 versus T3), surgical margins, lymph node and seminal vesicle involvement, age, race, preoperative prostate-specific antigen (PSA), and biochemical progression. Biochemical progression was defined as a persistently elevated postoperative PSA of 0.2 ng/mL or greater. RESULTS Thirty-two of the 40 tumors (80%) stained for mutant p53. None of the tumors that did not stain progressed, whereas 20 of 32 (62.5%) of the tumors that did stain progressed, with an overall mean followup of 50.8 months. Immunoreactivity did not correlate with any of the known prognostic variables but did have statistically significant correlation with progression by all three statistical methods used (Fishers exact test, logistic regression, and log-rank test). CONCLUSIONS Strict quality control and newer antigen retrieval techniques reveal p53 abnormalities in many prostate cancers. Immunohistochemical detection of mutant p53 appears to be an independent predictor of progression. These data suggest potential utility of p53 as a preoperative prognostic indicator in localized prostate cancer.

Diagnostic Value of HMB-45 and Anti-Melan A Staining of Sentinel Lymph Nodes with Isolated Positive Cells

Numerous immunohistochemical stains have been employed to detect metastatic melanoma in sentinel lymph node (SLN) biopsies. HMB-45 is considered by some as a specific tool to detect early metastatic melanoma (1). Occasionally, one or two isolated HMB-45–positive cells may cause complications in diagnostic interpretation. The goal of this study was to evaluate the reliability of HMB-45 staining of SLNs with sparse isolated positive cells and to compare its staining with anti–Melan A antibody. HMB-45 and anti–Melan A antibody immunostaining was performed on (Group A) 15 histologically negative SLNs excised from patients with malignant melanoma (MM) and on (Group B) 15 histologically negative SLNs excised from patients with breast carcinoma (BC). None of the patients had clinical evidence of systemic metastasis at the time of SLN biopsy. Five cutaneous biopsies with changes of postinflammatory hyperpigmentation (PIHP) were also stained with both antibodies. HMB-45 staining was repeated in all Group B SLNs after blocking endogenous biotins. Electron-microscopic studies were performed on all cases of PIHP. Isolated HMB-45–stained cells were present in 6 of 15 SLNs removed for MM; 8 of 15 for BC; and 3 of 5 cutaneous biopsies of PIHP. HMB-45 reactivity persisted after blocking endogenous biotins in 6 of 8 positive SLNs from Group B. Anti–Melan A antibody was negative in all SLNs of group A and B and in dermal melanophages of all five cases of PIHP. HMB-45 positivity was demonstrated in histologically negative SLNs and cutaneous biopsies, especially in the milieu of aggregated melanophages. Phagocytosis of premelanosomes by macrophages in the draining lymph nodes may account for isolated cell positivity and can hinder correct diagnostic interpretation. HMB-45 may not be a reliable marker for the detection of micro-metastasis of MM and requires correlation with other immunohistochemical markers, such as anti–Melan A antibody, to enhance specificity.

Solitary sclerotic fibroma of skin: a possible link with pleomorphic fibroma with immunophenotypic expression for O13 (CD99) and CD34

Background:  Solitary sclerotic fibroma (SF) presents as a well circumscribed dermal nodule, composed of sparse spindle cells with alternating wavy collagen fibers arranged in a storiform pattern. The histogenesis and nature of this histologically distinct lesion are uncertain. Whether this peculiar tumor represents a true hamartoma or a degenerating end of various fibrous lesions such as pleomorphic fibroma (PF), dermatofibroma, or angiofibroma is still controversial. High proliferating index of spindle cells in SF argues against the possibility of being a degenerating end product of another lesion.

Absence of B-cell or T-cell clonal expansion in nodular, lymphocyte predominant Hodgkin's disease

Recent studies based upon immunophenotypic data have provided strong evidence that nodular lymphocyte predominant Hodgkins disease (NLPHD) represents an entity that is distinct from other subtypes of Hodgkins disease (HD). In contract to other forms of HD, the predominance of B-lymphocytes in NLPHD has prompted the thesis that this lesion is actually an atypical B-cell hyperplasia or follicular center cell lymphoma. Three cases of NLPHD by restriction endonuclease analysis were studied in an attempt to identify a clonal B-cell or T-cell expansion in this disorder. DNA was extracted from these tumors and hybridized to probes for the immunoglobulin genes (C kappa, C lambda, JH) and the T-cell receptor beta chain gene. Gene rearrangements were not detectable in any of the cases. The results provide genotypic evidence that there is not a monoclonal or oligoclonal proliferation of small B-lymphocytes or T-lymphocytes in NLPHD. The possibility that the L&H Reed-Sternberg cells are monoclonal cannot be excluded because their small number is below the level of sensitivity of this technique.

Race modifies the association between breast carcinoma pathologic prognostic indicators and the positive status for HER-2/neu.

Inferences about the variations in the biology of breast carcinoma between African‐Americans and Caucasians have been reported. The difference in the prevalence of positive HER‐2/neu breast carcinoma was evaluated and the race‐specific risk was assessed for positive HER‐2/neu among a cohort of women diagnosed with their first primary breast carcinoma, given the accepted prognostic pathologic indicators for positive HER‐2/neu status.

The CD117 immunohistochemistry tissue microarray survey for quality assurance and interlaboratory comparison: a College of American Pathologists Cell Markers Committee Study.

CONTEXT We have developed tissue microarray-based surveys to allow laboratories to compare their performance in staining predictive immunohistochemical markers, including proto-oncogene CD117 (c-kit), which is characteristically expressed in gastrointestinal stromal tumors (GISTs). GISTs exhibit activating mutations in the c-kit proto-oncogene, which render them amenable to treatment with imatinib mesylate. Consequently, correct identification of c-Kit expression is important for the diagnosis and treatment of GISTs. OBJECTIVE To analyze CD117 immunohistochemical staining performance by a large number of clinical laboratories. DESIGN A mechanical device was used to construct tissue microarrays consisting of 3 x 1-mm cores of 10 tumor samples, which can be used to generate hundreds of tissue sections from the arrayed cases, suitable for large-scale interlaboratory comparison of immunohistochemical staining. RESULTS An initial survey of 63 laboratories and a second survey of 90 laboratories, performed in 2004 and 2005, exhibited >81% concordance for 7 of 10 cores, including all 4 GIST cases, which were immunoreactive for CD117 with >95% staining concordance. Three of the cores achieved less than 81% concordance of results, possibly due to the presence of foci of necrosis in one core and CD117-positive mast cells in 2 cores of CD117-negative neoplasms. CONCLUSIONS There was good performance among a large number of laboratories performing CD117 immunohistochemical staining, with consistently higher concordance of results for CD117-positive GIST cases than for nonimmunoreactive cases. Tissue microarrays for CD117 and other predictive markers should be useful for interlaboratory comparisons, quality assurance, and education of participants regarding staining nuances such as the expression of CKIT by nonneoplastic mast cells.

Use of microsatellite analysis in detection of tumor lineage as a cause of death in a liver transplant patient.

Malignant tumors are a significant cause of long-term morbidity and mortality in allograft recipients. Most solid tumors in transplant recipients are assumed to arise de novo in the setting of chronic immunosuppressive therapy; however, there have been instances in which malignant tumors have been transplanted in donated tissue from apparently healthy donors. We report a case of a 49-year-old liver transplant patient who presented with metastatic melanoma 9 months after transplantation for hepatocellular carcinoma and who later succumbed to the disease. To investigate the possibility that melanoma was derived from the donor liver, we used a commercially available polymerase chain reaction-based microsatellite marker assay to perform tissue identity testing. The genetic profiles of the patients original hepatocellular carcinoma and the melanoma from the autopsy specimen were compared with the profile of the normal donor liver tissue, which was still available for testing. The pattern of microsatellite allelic expression strongly suggested that the melanoma detected at autopsy originated from the transplanted liver.

Her-2/neu expression in primary breast cancer with sentinel lymph node metastasis.

BackgroundAmplification of the protein product of the HER-2/neu oncogene in primary breast cancer specimens is associated with an adverse prognosis. We hypothesized that overexpression of HER-2/neu would predict metastases to the sentinel lymph nodes (SLNs).MethodsA retrospective review of a prospective nonrandomized evaluation of 1055 clinically node-negative breast cancer patients undergoing 1063 SLN biopsies was performed. HER-2/neu analysis was performed by immunohistochemistry and, in selected cases, by fluorescence in situ hybridization. Clinical, demographic, surgical, radiological, and pathologic data were analyzed by using generalized estimating equations logistic regression models.ResultsTwo hundred thirty-two (23.6%) of 985 operations in which the SLN was found at operation resulted in positive nodes. In a multivariate analysis, size (P < .0001) and HER-2/neu overexpression (P = .026) were independent predictors of SLN metastasis.ConclusionsSize is a known predictor of SLN metastasis in the modern SLN era, as it was in the pre-SLN eras. HER-2/neu was found to be significantly predictive of SLN metastasis in our study. We anticipate a future when even the relatively minor procedure of SLN biopsy might be avoided with the predictive information gained from studying the pathology and molecular markers of primary breast cancers.

Immunoglobulin and T-cell receptor genes inthymomas: Genotypic evidence supporting the nonneoplastic nature of the lymphocytic component

On the basis of morphologic and immunophenotypic studies, it is generally accepted that the lymphocyte population in thymomas is not neoplastic. We studied 10 thymomas with restriction endonuclease and Southern blot/DNA hybridization methods in an attempt to provide genotypic evidence in support of this hypothesis. The clinical, gross, and microscopic features of each case were reviewed and found to be entirely consistent with the diagnosis of thymoma. In addition to conventional histologic methods, we also studied each tumor by immunohistologic techniques. The lymphocytes generally had an immunotype characteristic of immature cortical thymocytes, and the epithelial cells were uniformly stained by antikeratin antibodies. DNA probes for the T-cell receptor beta-chain gene and immunoglobulin genes (C kappa, C lambda, and JH) were used in the genotypic studies. No gene rearrangements were detected in any of the thymomas. This study provides additional evidence that clonal proliferations of T or B lymphocytes are not present in thymomas; therefore, these cells are almost certainly not neoplastic. The results also provide a basis for the effective use of restriction endonuclease and Southern blot/DNA hybridization analysis in the differential diagnosis of non-Hodgkins lymphoma and thymoma.

Concordance of the hormone receptors and correlation of HER-2/neu overexpression of the metachronous cancers of contralateral breasts.

Abstract:  The primary objective of this study was to evaluate the relative prevalence of estrogen receptor‐negative contralateral breast cancer to the first primary cancer and to assess the correlation between the relative overexpression of HER‐2/neu in the first primary cancer and contralateral breast cancer. A total of 144 women diagnosed with cancers in contralateral breasts were identified from the Henry Ford Health System tumor registry. Data were retrieved from electronic databases and medical records. Women were dichotomized into users and nonusers of tamoxifen. Hormone receptors were scored as positive or negative. HER‐2/neu overexpression, assessed by immunohistochemistry, was scored as 0, 1+, 2+, or 3+. Concordance between hormone receptors of the two cancers was low (κ = 0.27, p = 0.06). Stratification of women by tamoxifen therapy yielded an almost fivefold increase in the proportion of estrogen receptor‐negative cancers among the users, while the proportion of cancers expressing no estrogen receptor remained the same among the nonusers (39.6% versus 40.6%). Matched, archived, paraffin‐embedded specimens of the first and contralateral breast cancers were available for 57 women. The correlation between the relative overexpression of HER‐2/neu between the first primary and the contralateral breast cancer was 0.4 (p = 0.002). The higher prevalence of estrogen receptor‐negative contralateral breast cancer among tamoxifen users concurs with previous reports. The biological mechanism for this observation is not understood; however, it has been proposed that tamoxifen inhibits the proliferation of estrogen receptor‐positive breast cancer cells, while estrogen receptor‐negative cells may continue to grow because of selective pressure. The correlation between HER‐2/neu overexpression in the matched first primary and contralateral breast cancers was statistically significant, suggesting that the diagnosis of HER‐2/neu overexpression in contralateral breast cancer is associated with HER‐2/neu overexpression in the first primary cancer.