Gene expression changes associated with the progression of intraductal papillary mucinous neoplasms.

OBJECTIVES: The diagnosis of high-grade intraductal papillary mucinous neoplasm (IPMN) is difficult to distinguish from low-grade IPMN. The aim of this study was to identify potential markers for the discrimination of high-grade and invasive (HgInv) IPMN from low- and moderate-grade dysplasia IPMN. METHODS: Laser capture microdissection was used to isolate distinct foci of low-grade, moderate-grade, high-grade, and invasive IPMN from paraffin-embedded archival tissue from 14 patients who underwent resection for IPMN. Most samples included multiple grades in the same specimen. Affymetrix Human Exon microarrays were used to compare low- and moderate-grade dysplasia IPMN with HgInv IPMN. RESULTS: Sixty-two genes were identified as showing significant changes in expression (P ≤ 0.05 and a 2-fold cutoff), including up-regulation of 41 in HgInv IPMN. Changes in gene expression are associated with biological processes related to malignant behavior including cell motion, cell proliferation, response to hypoxia, and epithelial-to-mesenchymal transition. In addition, altered signaling in several transforming growth factor ß-related pathways was exhibited in the progression of IPMN to malignancy. CONCLUSIONS: This study identifies a set of genes associated with the progression of IPMN to malignancy. These genes are potential markers that could be used to identify IPMN requiring surgical resection.

Adjuvant role of p53 immunostaining in detecting BK viral infection in renal allograft biopsies.

BK virus infection is a significant threat to renal transplant outcome. Detecting viral infection in renal transplant biopsies using SV40 staining is less than ideal. SV40 antibody reacts with the large T-antigen of BK virus only at the early phases of infection and can miss cells in later stages of infection. As p53 is upregulated during both early and late phases of infection, this study set out to determine whether p53 staining could improve detection of BK virus infection in renal transplant patients. The control group consisted of 16 renal allograft biopsies without histologic evidence of BK virus infection, while the BK group consisted of 15 renal allograft biopsies with histologic evidence of BK virus infection. The biopsies from both groups were immunohistochemically stained with both SV40 and p53 antibodies. Dual staining with both markers was also performed to identify their nuclear co-localization. In the BK group, the percent of p53 staining (16.6 ± 4.8 %) was significantly higher than the percent of SV40 staining (5.4 ± 2.7%). BK virus infected cells revealed a unique p53 immunostaining pattern (strong nuclear staining with a central halo). Co-localization of SV40 and p53 was identified in cells that had characteristic nuclear features of BK virus infection by histology. The sensitivity and specificity for using p53 staining to identify BK infected cells was 92% and 86 %, respectively. In conclusion, p53 staining detects a higher percentage of BK virus infected cells than SV40 staining alone. Thus, for diagnosis of BK virus infection in renal allograft biopsies, p53 staining is a sensitive and specific method when used along with SV40 staining.

Estrogen receptor alpha and progesterone receptor expression in ovarian adult granulosa cell tumors and Sertoli-Leydig cell tumors.

The biologic role that estrogen receptor (ER) and progesterone receptor (PR) play in ovarian sex cord-stromal tumors is poorly understood. Furthermore, immunohistochemical data on these hormone receptors in this group of neoplasms are limited and conflicting, with many reports suggesting that expression of ERalpha and/or PR is either infrequent or present at low levels in granulosa and Sertoli cell tumors. Immunohistochemical staining for ERalpha and PR was performed in 69 ovarian sex cord-stromal tumors: 41 adult granulosa cell tumors and 28 Sertoli-Leydig cell tumors. Extent of expression was scored based on the percentage of positive cells: 0, 5% or less; 1+, 6% to 25%; 2+, 26% to 50%; 3+, 51% to 75%; and 4+, 76% to 100%. Estrogen receptor alpha and PR were frequently expressed in adult granulosa cell tumors (66% and 98%, respectively) and Sertoli-Leydig cell tumors (79% and 86%, respectively). Diffuse (3+ or 4+) expression of PR was more common in adult granulosa cell tumors (68% vs. 36%; P = 0.013), whereas diffuse (3+ or 4+) expression of ERalpha was more frequent in Sertoli-Leydig cell tumors (50% vs. 20%; P = 0.010). In cases positive for both markers, adult granulosa cell tumors exhibited a focal (1+ or 2+) ERalpha/diffuse (3+ or 4+) PR coordinate profile more commonly than Sertoli-Leydig cell tumors (52% vs. 18%; P = 0.02), whereas Sertoli-Leydig cell tumors displayed a diffuse (3+ or 4+) ERalpha/focal (1+ or 2+) PR profile more frequently than adult granulosa cell tumors (36% vs. 0%; P = 0.0007). We conclude that expression of hormone receptors (based only on frequency of immunostaining) does not allow for distinction from other tumors in the differential diagnosis that are known to be frequently positive for ERalpha and PR such as endometrioid neoplasms. Most adult granulosa cell tumors and Sertoli-Leydig cell tumors share overlapping patterns of expression of ERalpha and PR with each other, but a subset of cases in each tumor category exhibits unique ERalpha/PR immunoprofiles (eg, focal ERalpha/diffuse PR in adult granulosa cell tumors and diffuse ERalpha/focal PR in Sertoli-Leydig cell tumors). These patterns of expression of ERalpha and PR may aid our understanding of the biologic differences between granulosa and Sertoli cell tumors.

The role of pre-operative CT-guided FNAB for parapharyngeal space tumors.

OBJECTIVE: To determine the role of computed tomography (CT)-guided fine needle aspiration biopsy (FNAB) in surgical planning for parapharyngeal space (PPS) tumors. DESIGN AND SETTING: Chart review of 49 consecutive patients with surgically treated PPS tumors from 1995 to 2005. RESULTS: Twenty-nine patients had CT-guided FNAB. A cytopathologic diagnosis that was the same as final pathology was rendered in 14 (48%) patients; suggestive but not conclusive in 6 (21%) patients; discordant in 3 (10%) patients; and 6 (21%) patients had a nondiagnostic result. Fourteen of 15 patients who had a final histopathologic finding of pleomorphic adenoma had a correct or highly suggestive preoperative FNAB diagnosis. The positive predictive value for CT-guided FNAB to identify benign tumors is 90%, (18 of 20) but to identify malignant PPS tumors is 75% (3 of 4). CONCLUSION: CT-guided FNAB of PPS tumors is helpful to predict the nature of the PPS tumors (especially benign), which allows the surgeon and patient to plan for treatment, accordingly.

Utility of immunohistochemistry for alpha-methylacyl-CoA racemase in distinguishing atrophic prostate cancer from benign atrophy.

Small atrophic prostate cancers on needle biopsy are rare and difficult to distinguish from benign atrophy on needle biopsy. We report on a study of 23 needle biopsy specimens with small foci of atrophic prostate cancer from the consult service of one of the authors. In 19 cancer cases the atrophic component was pure; in 4 cases it was dominant with a minor (<5%) nonatrophic cancer component. These atrophic cancers and 16 cases of florid benign atrophy on needle biopsy were examined by immunohistochemistry for alpha-methylacyl-CoA-racemase (AMACR). All cases of cancer and atrophy were verified immunohistochemically with antibodies to basal cells (34betaE12 and p63). AMACR staining were scored as 1+ (5% to 25% of glands expressing AMACR), 2+ (26% to 50% of glands expressing AMACR), or 3+ (>50% of glands expressing AMACR). Positive staining was defined as staining above that of surrounding benign glands. AMACR was expressed in 69.6% of atrophic prostate cancers (3+, 11 cases; 2+, 3 cases; 1+, 2 cases); 30.4% (7 cases) of atrophic prostate cancer exhibited no AMACR expression. In the 4 cases with a few glands of ordinary (nonatrophic) prostate cancer, the nonatrophic cancer demonstrated more intense and a greater extent of AMACR staining. Fourteen cases (87.5%) of benign atrophy showed no AMACR expression. In 2 cases (12.5%) of benign atrophy, background immunostaining made it difficult to assess AMACR expression. We conclude that AMACR immunostaining alone is not sufficiently discriminatory in the differential diagnosis of atrophic prostate cancer versus benign atrophy. Atrophic prostate cancers are not as frequently or as strongly positive as ordinary prostate cancer. Using a panel of immunostains including AMACR, 34betaE12 and p63 (positive AMACR immunostaining along with negative basal cell markers) is recommended in the differentiation of atrophic prostate cancer and benign atrophy.

Plasmacytoma with involvement of the urinary bladder. Report of a case diagnosed by urine cytology.

BACKGROUND: Plasmacytoma of the bladder is a rare but important entity. We report a case of plasmacytoma of the bladder that was diagnosed by urinary cytology. CASE: A 71-year-old male with a history of multiple myeloma presented in renal failure. Renal ultrasound revealed right-sided, moderate hydronephrosis with a 4 x 4-cm, posterolateral, obstructing mass. Magnetic resonance imaging demonstrated a bladder mass involving the bladder base, right lateral wall and dome with extension into the perivesical tissues on the right. The mass showed a moderate degree of enhancement following intravenous gadolinium administration. Urine cytology was performed to evaluate for bladder carcinoma or other malignancies besides plasmacytoma. The specimen was signed out as multiple myeloma of the bladder. Cystoscopy and biopsy were subsequently performed on the bladder mass. The diagnosis of plasmocytoma was made, confirming the urine cytology diagnosis. CONCLUSION: Urinary cytology can be a diagnostic tool for plasmocytoma involving the bladder.

CD56 expression of neuroendocrine neoplasms on immunophenotyping by flow cytometry: a novel diagnostic approach to fine-needle aspiration biopsy.

BACKGROUND: CD56 antigen or NCAM (neural cell adhesion molecule) has an established role in the diagnosis of non-Hodgkin lymphoma (NHL)-natural killer cell type and other hematologic malignancies. Therefore, it is included routinely in the panel of antibodies for flow cytometric (FC) analysis of suspected lymphomatous tissue specimens obtained from fine-needle aspiration biopsy (FNAB). The authors evaluated the role of CD56 expression on FC of neuroendocrine (NE) tumors. An initial diagnosis of NHL was suspected based on an on-site FNAB evaluation. METHODS: Ten FNABs were identified from the cytopathology files at The Johns Hopkins Hospital, Baltimore, MD (2000-2001). Flow cytometric analysis was negative for NHL but revealed a CD56-positive nonlymphoid cell population. An FNAB evaluation was performed on air-dried Diff-Quik-stained smears and FC analysis used a fixed panel of 12 antibodies (B-cell markers, T-cell markers, CD33, CD56, and CD71). Immunoperoxidase staining (IPOX) was performed on the cell block sections from four of the tissue specimens using epithelial and NE markers, CD56, desmin, and O13 antibodies. Sites of FNAB included the lung (five cases), liver (one case), lymph node (three cases), and peritoneum (one case). Only one patient had a history of cancer at the time of FNAB. RESULTS: All cytologic diagnoses were confirmed by histopathologic follow-up on resection or biopsy or both. Diagnoses included small cell carcinoma (eight cases), Merkel cell carcinoma (one case), and primitive neuroectodermal tumor/Ewing sarcoma (one case). All tissue specimens that underwent IPOX stained strongly with NE markers, with one tissue section staining only with O13. CONCLUSIONS: CD56 expression by FC in the presence of negative immunostaining with lymphoid markers represented a unique yet highly specific method for the diagnosis of NE tumors by FNAB. This procedure eliminated the need for further IPOX studies on the already limited cytologic sample and provided a timely and accurate diagnosis.