Histopathological and immunophenotypic features of ipilimumab-associated colitis compared to ulcerative colitis.

BACKGROUND: Use of the immune checkpoint inhibitor ipilimumab is sometimes complicated by ipilimumab-associated colitis (Ipi-AC), an immune-mediated colitis that mimics inflammatory bowel disease. OBJECTIVE: We sought to characterize the histopathologic and immunophenotypic features of Ipi-AC and to directly compare these features to ulcerative colitis (UC). METHODS: This is a retrospective cohort study of 22 patients with Ipi-AC, 12 patients with treatment-naïve UC and five controls with diarrhoea but normal endoscopic findings. Immunohistopathologic features were described, and quantitative immunohistochemistry (IHC) was performed for CD4, CD8, CD20, CD138 and FOXP3. RESULTS: Endoscopic findings in both the Ipi-AC and UC groups included ulcerated, oedematous and erythematous mucosa. Involvement of the GI tract was more diffuse in Ipi-AC. As compared to UC, a smaller proportion of Ipi-AC biopsies had basal plasmacytosis (14% for Ipi-AC vs. 92% for UC, P < 0.0001) and crypt distortion (23% for Ipi-AC vs. 75% for UC, P = 0.003), whereas Ipi-AC biopsies had more apoptotic bodies in the left colon (17.6 ± 15.3 for Ipi-AC vs. 8.2 ± 4.2 for UC, P = 0.011). Cryptitis, ulcerations and crypt abscesses were common in both groups. Biopsy specimens from Ipi-AC had a lower density of CD20-positive lymphocytes than UC (275.8 ± 253.3 cells mm-2 for Ipi-AC vs. 1173.3 ± 1158.2 cells mm-2 for UC, P = 0.022) but had a similar density of CD4, CD8, CD138 and FOXP3-positive cells. CONCLUSIONS: Ipi-AC is a distinct pathologic entity with notable clinical and histopathological differences compared to UC. These findings provide insights into the pathophysiology of immune-related adverse events (iAEs) from ipilimumab therapy.

MRI characteristics associated with high-grade myxoid liposarcoma.

AIM: To identify magnetic resonance imaging (MRI) features differentiating high-grade (>5% round-cell component) from low-grade myxoid liposarcomas (LPS) (≤5% round-cell component). MATERIALS AND METHODS: Informed consent was waived. Patients with myxoid LPS and MRI before biopsy, neoadjuvant therapy, and surgery were included retrospectively. High-grade components were recorded from histological specimens by a pathologist (24 years of experience). Images were evaluated by a senior radiologist (>12 years of experience) for tumour size, location, tissue layer, and MRI features (signal intensity, heterogeneity, margin, and perilesional characteristics). Descriptive statistics, Fisher's exact test to identify associations with a round-cell component, and multivariate logistic regression to identify independent predictors of high-grade tumours were used. RESULTS: Thirty-one patients (16 women [mean 51.1 years; range 19-79 years] and 15 men [mean 45.5 years; range 18-95 years]) with myxoid LPS (23 low-grade, eight high-grade) were included. All high-grade lesions had lipid signal, a peritumoural capsule and peritumoural contrast enhancement, and more commonly exhibited heterogeneous signal; however, the average size of ≥10 cm was the strongest independent indicator of high-grade status (odds ratio [OR], 14.6; 95% confidence interval [CI]: 1.6, 131). CONCLUSION: Size ≥10 cm is most strongly associated with high-grade myxoid LPS (round-cell component >5%). Other features possibly differentiating high-grade from low-grade status include lesion margin, lipid signal, and perilesional characteristics.

Gender is a determinative factor in the initial clinical presentation of eosinophilic esophagitis.

Eosinophilic esophagitis (EoE) is a chronic, immune-mediated disease resulting in symptoms of esophageal dysmotility. Abnormalities include dysphagia, food impaction and reflux. Although men appear to comprise a majority of the EoE population, few studies have directly assessed gender-associated clinical differences. The aim of this study is to identify the effect of gender on the initial clinical presentation of adult-onset EoE patients. We reviewed our electronic medical record database from January 2008 to December 2011 for adults diagnosed with EoE per the 2011 updated consensus guidelines. Patient demographics, presenting symptoms, endoscopy findings and complications were recorded. Proportions were compared using chi-squared analysis, and means were compared using the Student's t-test. A total of 162 patients met the inclusion criteria and 71 (44%) were women. Women were more likely to report chest pain (P = 0.03) and heartburn (P = 0.06), whereas men more commonly reported dysphagia (P = 0.04) and a history of food impaction (P = 0.05). Endoscopic findings were similar between groups. No patients suffered esophageal perforations. These data suggest that men report more fibrostenotic symptoms and women report more inflammatory symptoms at the time of diagnosis. There was no difference in endoscopic findings between genders. This is one of the only reviews comparing differences in clinical presentation, endoscopic findings and complications between gender for EoE. The current recommended guidelines state that any patient with symptoms of esophageal dysfunction should be biopsied for EoE. Our findings support biopsying patients with typical and atypical symptoms of dysmotility including heartburn and chest pain.

Squamous cell carcinoma in Barrett's esophagus: field effect versus metastasis.

Barrett's esophagus (BE) is a premalignant condition with an increased risk of developing esophageal adenocarcinoma (EAC). Risk factors for EAC overlap with those for esophageal squamous cell carcinoma (ESCC), but ESCC is surprisingly rare in BE. We report two cases of ESCC directly surrounded by BE. Both patients had a previous medical history of cancers, i.e., head and neck squamous cell carcinomas, and were using alcohol and smoking tobacco. Using immunohistochemistry for p63, CK5, CK7, and CDX2, it was confirmed that these carcinomas were pure squamous cell carcinomas, and not EACs or esophageal adenosquamous carcinomas arising from BE. Using TP53 mutation and loss of heterozygosity analysis, we established that the ESCCs in BE were not metastases of the previously diagnosed head and neck squamous cell carcinomas but de novo primary ESCCs. This study shows the strength of molecular analysis as an adjunct to the histopathologic diagnosis for distinguishing between metastases of prior cancers and primary cancers. Furthermore, these cases imply that presence of BE is not protective with regards to developing ESCC in the lower one third of the esophagus. We suggest that their ESCCs arose from islets of squamous epithelium in BE.

An action potential-induced and ryanodine sensitive calcium transient dynamically regulates transmitter release at synapses between Lymnaea neurons.

The notion that calcium released through ryanodine receptors effects presynaptic neurotransmitter release is gaining acceptance with the observation that this calcium does indeed contribute to both action potential-evoked and spontaneous transmitter release in a variety of preparations. However, the dynamics of this calcium release and its impact on transmitter release has not yet been fully elucidated. Moreover, in contrast to vertebrate synapses, much less is known about the involvement of ryanodine receptors in the regulation of transmitter release at invertebrate synapses. In this study, we reconstructed specific synapses between individually identifiable preand postsynaptic neurons from Lymnaea to demonstrate that although ryanodine reduces the amplitude of the action potential-induced calcium transient, it does not however, alter the resting calcium level. These data suggest that action potential-induced calcium release through ryanodine receptors is fast and highly dynamic and in turn regulates transmitter release at reconstructed synapses between Lymnaea neurons. This study thus provides direct evidence that a dynamic ryanodine receptor-mediated calcium transient occurs with the presynaptic action potential.

Counting alleles reveals a connection between chromosome 18q loss and vascular invasion.

The analysis of loss of heterozygosity (LOH) is perhaps the most widely used technique in cancer genetics. In primary tumors, however, the analysis of LOH is fraught with technical problems that have limited its reproducibility and interpretation. In particular, tumors are mixtures of neoplastic and nonneoplastic cells, and the DNA from the nonneoplastic cells can mask LOH. We here describe a new experimental approach, involving two components, to overcome these problems. First, a form of digital PCR was employed to directly count, one by one, the number of each of the two alleles in tumor samples. Second, Bayesian-type likelihood methods were used to measure the strength of the evidence for the allele distribution being different from normal. This approach imparts a rigorous statistical basis to LOH analyses, and should be able to provide more reliable information than heretofore possible in LOH studies of diverse tumor types.

RNA helicase DDX3: a novel therapeutic target in Ewing sarcoma.

RNA helicase DDX3 has oncogenic activity in breast and lung cancers and is required for translation of complex mRNA transcripts, including those encoding key cell-cycle regulatory proteins. We sought to determine the expression and function of DDX3 in sarcoma cells, and to investigate the antitumor activity of a novel small molecule DDX3 inhibitor, RK-33. Utilizing various sarcoma cell lines, xenografts and human tissue microarrays, we measured DDX3 expression at the mRNA and protein levels, and evaluated cytotoxicity of RK-33 in sarcoma cell lines. To study the role of DDX3 in Ewing sarcoma, we generated stable DDX3-knockdown Ewing sarcoma cell lines using DDX3-specific small hairpin RNA (shRNA), and assessed oncogenic activity. DDX3-knockdown and RK-33-treated Ewing sarcoma cells were compared with wild-type cells using an isobaric mass-tag quantitative proteomics approach to identify target proteins impacted by DDX3 inhibition. Overall, we found high expression of DDX3 in numerous human sarcoma subtypes compared with non-malignant mesenchymal cells, and knockdown of DDX3 by RNA interference inhibited oncogenic activity in Ewing sarcoma cells. Treatment with RK-33 was preferentially cytotoxic to sarcoma cells, including chemotherapy-resistant Ewing sarcoma stem cells, while sparing non-malignant cells. Sensitivity to RK-33 correlated with DDX3 protein expression. Growth of human Ewing sarcoma xenografts expressing high DDX3 was inhibited by RK-33 treatment in mice, without overt toxicity. DDX3 inhibition altered the Ewing sarcoma cellular proteome, especially proteins involved in DNA replication, mRNA translation and proteasome function. These data support further investigation of the role of DDX3 in sarcomas, advancement of RK-33 to Ewing sarcoma clinical trials and development of RNA helicase inhibition as a novel anti-neoplastic strategy.

Transposable Elements in Mendelian Populations. II. Distribution of Three COPIA-like Elements in a Natural Population of DROSOPHILA MELANOGASTER.

Twenty X chromosomes isolated from a natural population of Drosophila melanogaster were surveyed using in situ hybridization to determine the number and cytogenetic location of three families of transposable elements: copia, 412 and 297. We found no sites of insertions in high frequency; in fact, frequencies of specific sites for all three elements were so low that each insertion could be interpreted as being unique. This suggests that rates of transposition and deletion for these elements are very high. Our data also show a higher than expected rate of the co-occurrence of different elements at the same site on the same chromosome.

OM Mutations in DROSOPHILA ANANASSAE Are Linked to Insertions of a Transposable Element.

It has been hypothesized that Om mutability in Drosophila ananassae (involving spontaneous mutation at 20 loci, resulting in semidominant, nonpleiotropic eye morphology defects) was due to insertion of a transposable element, tom. One particularly unstable X-linked Om allele produced several derivatives, one of which has a more extreme Om phenotype and was accompanied by a singed bristle mutant, sn( 9g). DNA probes from the sn locus of D. melanogaster were used to clone the homologous region of D. ananassae. Analysis of sn(9g) DNA detected a 6.5-kb insert. Genomic Southern blotting and in situ hybridization techniques showed that this insert is repetitive and dispersed. The existence of the tom element is supported by genetic mapping that established homology between the 6.5-kb sn(9g) insert and Om mutants at the four X-linked loci tested.

Chromosome rearrangement by ectopic recombination in Drosophila melanogaster: genome structure and evolution.

Ectopic recombination between interspersed repeat sequences generates chromosomal rearrangements that have a major impact on genome structure. A survey of ectopic recombination in the region flanking the white locus of Drosophila melanogaster identified 25 transposon-mediated rearrangements from four parallel experiments. Eighteen of the 25 were generated from females carrying X chromosomes heterozygous for interspersed repeat sequences. The cytogenetic and molecular analyses of the rearrangements and the parental chromosomes show: (1) interchromosomal and intrachromosomal recombinants are generated in about equal numbers; (2) ectopic recombination appears to be a meiotic process that is stimulated by the interchromosomal effect to about the same degree as regular crossing over; (3) copies of the retrotransposon roo were involved in all of the interchromosomal exchanges; some copies were involved much more frequently than others in the target region; (4) homozygosis for interspersed repeat sequences and other sequence variations significantly reduced ectopic recombination.

Immunohistochemical staining for glutathione S-transferase predicts response to platinum-based chemotherapy in head and neck cancer.

The glutathione S-transferases (GSTs) play an important role in the cell's defense against toxic substances. The GSTs are a family of enzymes produced by several genes that interact with distinct but overlapping substrates and that may play a role in resistance of tumor cells to several chemotherapeutic agents. We examined the correlation between expression of GSTs determined by immunohistochemistry and clinical response to platinum-based chemotherapy in 51 patients with head and neck cancer, who received a total of 56 courses of chemotherapy. The overall response rate for the 56 chemotherapy treatment courses was 48%. The overall response rate (complete response + partial response) for patients with low GST scores was 88% (21 of 24), whereas among the patients with high GST scores, the overall response rate was 19% (6 of 32; P = 0.001). Patients with a low GST score were 4.7 times more likely to respond to chemotherapy than patients with high GST scores. GST scores corresponded to response in 84% of cases. Among 23 patients treated with neoadjuvant chemotherapy, the overall response rate for patients with low GST scores was 100% (14 of 14), whereas among the patients with high GST scores, the overall response rate was 44% (4 of 9; P = 0.002). Among 33 patients treated with chemotherapy for relapsed disease, the overall response rate for patients with low GST scores was 70% (7 of 10), whereas among the patients with high GST scores, the overall response rate was 8.6% (2 of 23; P < 0.001). We conclude that GST expression correlates well with response to platinum-based chemotherapy in head and neck cancer.

Nodular fasciitis. Its morphologic spectrum and immunohistochemical profile.

Although nodular fasciitis (NF) is a well recognized pseudosarcomatous proliferation, it continues to cause diagnostic problems. We reviewed the clinical, histologic and immunohistochemical features of 53 lesions from 30 male and 23 female patients, ages 8-76 years, that involved the upper and lower extremities, trunk, and head and neck. Sizes ranged from 0.6 to 6.5 cm. The morphologic spectrum was broad, including the classic pattern of delicate fibroblasts suspended in a myxoid matrix, granulation tissue-like areas, solid and whorled myofibroblastic proliferations with multinucleated cells, mucoid cysts, and so-called "ancient" forms with dense, refractile strands of keloid-like collagen. Nodular fasciitis was correctly diagnosed in 23 cases (43%); a sarcoma was diagnosed in 11 (21%). A characteristic immunohistochemical profile emerged wherein 49 of 53 cases stained for smooth-muscle and muscle-specific actins, vimentin, and KP1 (a histiocyte marker), indicating dual myofibroblastic and histiocytic differentiation. None of the lesions expressed keratin, S-100 protein, or desmin. Knowledge of the immunohistochemical profile of nodular fasciitis and its overlap with certain sarcomas can decrease the likelihood of misdiagnosis.

Rosai-Dorfman disease of soft tissue.

Whereas Rosai-Dorfman disease (RDD) or sinus histiocytosis with massive lymphadenopathy is well described in lymph nodes and other organs, it is frequently not recognized in soft tissue. We studied the clinical and histologic features of 23 previously unreported soft tissue lesions from 17 patients (13 females, 4 males) who were 24 to 66 years of age (mean, 46 years). These lesions involved the extremities (12, 52%), trunk (6, 26%), head and neck (3, 13%), and the retroperitoneum (2, 9%). Associated lymph node involvement was present in four cases; most patients were asymptomatic. RDD of soft tissue had more subtle histologic features than its lymph node counterpart. Emperipolesis was less conspicuous and proliferating histiocytes were frequently spindled, associated with collagen deposition, and arranged in a vague storiform pattern with scattered lymphoplasmacytic aggregates. These features led to a variety of diagnoses, including benign inflammatory and fibrohistiocytic lesions (13 cases) as well as lymphoma and malignant fibrous histiocytoma (three cases). RDD was correctly diagnosed in only one case. Diagnosis was confirmed in 16 of 18 lesions by detection of S-100 protein and histiocytic markers KP1 (12 of 13) and lysozyme (eight of 11) in the characteristic histiocytes. Recognition that RDD of soft tissue occurs in an older patient population than does nodal RDD and that it mimics fibrous and inflammatory lesions of soft tissue is important.

Calcifying fibrous pseudotumor.

We report 10 cases of a distinctive benign fibrous lesion characterized by the presence of abundant hyalinized collagen with psammomatous or dystrophic calcifications and a lymphoplasmacytic infiltrate. The lesions were present from 2 months to 10 years before resection and ranged in size from 2.5 to 15 cm. They involved subcutaneous and deep soft tissues and, although relatively well-circumscribed, occasionally infiltrative borders or entrapped structures were seen on microscopic examination. The lesions were located in the extremities (three cases), trunk (two cases), scrotum (two cases), groin (one case), neck (one case), and axilla (one case). Both sexes were equally affected. The mean and median ages of the patients were 16.2 and 18.5 years, respectively (range, 1 to 33 years). All cases were initially managed by simple local excision. Follow-up ranging from 2 months to more than 10 years (median, 41.5 months) was available in six cases and revealed a local recurrence in one instance; this became clinically apparent about 7.5 years after the initial resection. Morphologic features and follow-up data suggest this may be a unique form of fibrous pseudotumor.

Atypical decubital fibroplasia. A distinctive fibroblastic pseudotumor occurring in debilitated patients.

We report 28 cases of atypical decubital fibroplasia, a distinctive pseudosarcomatous fibroblastic proliferation occurring primarily but not exclusively in physically debilitated or immobilized patients. The subjects included 16 women and 12 men ranging in age from 15 to 95 years. Peak incidence was in the 8th and 9th decades of life. Anatomic locations included the soft tissues overlying the shoulder (eight cases), posterior chest wall (five cases), sacrum (five cases), greater trochanter (four cases), buttock (two cases), thigh (two cases), and arm (two cases). Symptoms were due to a painless mass of 3 weeks' to 6 months' duration. Most lesions were ill-defined, focally myxoid masses that ranged from 1 to 8 cm. Histologically, they were situated in the deep subcutis and secondarily involved adjacent skeletal muscle (11 cases) and tendon (three cases). Extensive epidermal ulceration was typically absent. Microscopically, the lesions had a lobular configuration. They were characterized by zones of fibrinoid necrosis and a prominent myxoid stroma rimmed by ingrowing, ectatic, thin-walled vascular channels. All cases contained atypical, enlarged, degenerated fibroblasts with abundant basophilic cytoplasm, large hyperchromatic, smudged nuclei, and prominent nucleoli; these features resulted in a superficial resemblance to proliferative fasciitis. The enlarged, atypical fibroblasts stained diffusely and strongly for vimentin (15 of 15 cases) and focally for muscle-specific actin (10 of 15 cases), keratin (one of 15 cases), CD68 (10 of 15 cases), and CD34 (five of nine cases) antigens; none of the cases stained for desmin. A malignant diagnosis was considered in 43% of cases. Follow-up in 21 patients ranged from 2 to 78 months (median, 12 months). Two lesions recurred once, one recurred twice, and none metastasized; no deaths were attributable to the lesions. The clinical, histologic, and immunohistochemical features of atypical decubital fibroplasia indicate it is a unique type of pressure sore displaying degenerative and regenerative features distinct from decubitus ulcer. Its recognition by pathologists and clinicians in elderly and debilitated patients is important to avoid misdiagnosis as a sarcoma and to prevent or minimize the occurrence of decubital fibroplasia in progressively aging patient populations.

Intussusception, adenovirus, and children: a brief reaffirmation.

Surgical specimens (n = 48) or autopsy case materials (n = 15) were studied from 63 pediatric patients (44 males and 19 females) with intussusceptions involving the ileocecal junction (38 patients [60.3%]), ileum (16 patients [25.4%]), jejunum (four patients [6.3%]), and other sites (five patients [8%]). Lymphoid hyperplasia formed the leading edge in 32 cases (51%); other lesions included Meckel diverticulum (six cases), lymphoma (four cases), adenomyomatous hamartoma (four cases), cecal duplication cyst (three cases), ectopic pancreas (two cases), congenital bowel malformation (two cases), and examples of Peutz-Jeghers polyp, lymphangioma, leiomyoma, and inflammatory fibroid polyp (one case each). In six cases there was no associated lesion. Immunohistochemical evaluation for adenovirus was performed in 16 of the 32 cases in which lymphoid hyperplasia was present, and five reactive cases were identified; characteristic intranuclear adenovirus inclusions were visible on hematoxylin-eosin-stained specimens from all five of these cases as well as in five additional cases (a total of 10 of 32 cases [31.2%]). The presence of Yersinia sp was confirmed by serology in one case having characteristic histologic findings. Fourteen deaths were attributable to consequences of intussusception; these patients were younger (median and mean ages, 5.5 and 8.6 months; age range, 1 month to 3.5 years) than the surviving patients (median and mean ages, 2.0 and 3.2 years; age range, 6 days to 14 years), but were not more likely to have evidence of adenovirus infection.

What are the CD34+ cells in benign peripheral nerve sheath tumors? Double immunostaining study of CD34 and S-100 protein.

To determine whether CD34 expression in nerve sheath lesions was found in a unique cell population or in a subset of nerve sheath cells, we performed double immunohistochemical staining using a standard avidinbiotin complex method with 2 separate color developing systems. We studied 40 neurofibromas and 16 neurilemomas. All lesions strongly expressed S-100 in nuclei and cytoplasm. CD34 was detected in cells having ameboid dendritic cytoplasm present in greatest numbers in Antoni B zones of neurilemomas, myxoid zones of neurofibromas, at the periphery of lobules in both tumor types, and condensed in apposition to perineurium. The CD34+ cells also were detected in normal nerves. They were infrequent in Antoni A zones of neurilemomas. No dual S-100 and CD34 expression was seen. This double immunostaining confirms the presence of a CD34-reactive non-Schwannian cell type in these neural neoplasms. As the CD34+, S-100-negative cell population is present also in normal nerves and infrequently seen in the areas of cellular neoplastic Schwann cells, CD34+, S-100-negative cells in peripheral nerve sheath tumors most likely are nonneoplastic and may have a supportive function.

Rapid diagnosis of Campylobacter pylori by Gram's stain.

Campylobacter pylori (CP) is implicated as a probable pathogen in gastritis and peptic ulcer disease. A blinded prospective study of 112 subjects evaluated how Gram's-stained touch preparations of mucosal biopsies compared with culture, routinely processed hematoxylin and eosin (H and E) and Warthin-Starry (WS) staining in confirming the presence of CP. At endoscopic examination, two mucosal biopsies were taken from the gastric antrum and two from the fundus of each subject. One biopsy from each site was Gram's stained and cultured and the other submitted for H and E and WS. Fifty of the 112 subjects had positive results for CP by at least two of the tests (44.6%). Histologically, 48 (96%) of the CP-positive subjects showed the presence of gastritis. Of 55 subjects who had gastritis, 50 had CP (91%). If both sites in the stomach were taken into account, the sensitivity and specificity of Gram's staining in detecting CP were 92% and 100%, respectively. These results are comparable to H and E and WS and slightly better than culture. The diagnosis of CP can be made accurately, rapidly, and inexpensively by Gram's stained touch preparations of mucosal biopsies.

Endoscopic mapping and surrogate markers for better surveillance in Barrett esophagus. A study of 700 biopsy specimens.

Surveillance methods in Barrett esophagus (BE) using light microscopic examination of random biopsy specimens may miss focal dysplasia. In addition, dysplastic foci identified initially may not be relocated subsequently, making chemoprevention studies difficult. By using a special gastroscope, systematic mapping (4-quadrant biopsy specimens at 1-cm intervals) was performed in 22 patients (33 total mappings yielding 700 biopsy specimens). H&E, immunohistochemistry, and DNA ploidy analysis were performed. c-erbB-2 and positive Ki-67 were detected only in dysplastic sites; thus, their detection did not precede morphologically identifiable dysplasia. On the other hand, aneuploidy and p53 were detected in dysplastic and nondysplastic areas. p53 was correlated with dysplasia, and S-phase narrowly missed correlation, while aneuploidy was not correlated. PCNA and bcl-2 were ubiquitous, limiting their usefulness. On second maps, epithelial type was reidentified with 81% accuracy. A significant correlation was found between p53 and dysplasia. Sites of dysplasia and abnormal biomarkers could be relocated accurately by using endoscopic mapping. Therefore, mapping combined with biomarker studies may provide better surveillance and serve as a useful technique in chemoprevention studies.

Barrett esophagus with dysplasia. Flow cytometric DNA analysis of routine, paraffin-embedded mucosal biopsies.

Flow cytometric DNA ploidy analysis has been reported to be more objective and sensitive than morphologic evaluation as a surveillance method in patients with Barrett esophagus (BE) for the development and progression of precancerous lesions. Such analyses are typically performed using fresh samples that require a separate or "jumbo" biopsy, are prone to false DNA aneuploidy if not promptly processed, and do not allow for retrospective studies. The feasibility of performing flow cytometric DNA analysis on paraffin-embedded biopsies was studied to circumvent some of these problems using 12 squamous esophageal mucosa with inflammation and 58 BE cases showing varying degrees of dysplasia. Among the BE cases, 12 had no dysplasia, 20 were indefinite for dysplasia, 14 had low grade dysplasia, and 12 had high grade dysplasia. Satisfactory histograms were obtained in 86% of the analyzed samples. Among cases with adequate histograms, DNA aneuploidy was identified in 77% with high grade dysplasia, 16% with low grade dysplasia, 23% of indefinite for dysplasia, and 0% without dysplasia. One of the esophagitis samples was also DNA aneuploid. Correlation of DNA aneuploidy and degree of dysplasia is highly significant (P = .001). The authors have demonstrated that routinely processed paraffin-embedded biopsies can be used for flow cytometric ploidy analysis. DNA aneuploidy was highly correlated with degree of dysplasia and serves as a quantitative prognostic indicator for prospective as well as retrospective studies of the evolution of BE to carcinoma.