Biliary stricture secondary to donor B-cell lymphoma after orthotopic liver transplantation.

Biliary complications after orthotopic liver transplantation (OLT) lead to considerable morbidity and occasional mortality after surgery. Bile duct strictures secondary to localized lymphoproliferative disorder of the porta hepatis is rare, with only 12 cases reported in the English literature. Posttransplant lymphoproliferative disorder develops in up to 9% of liver allograft recipients. We describe 2 adult patients who developed Epstein-Barr virus-associated localized B-cell lymphoma of donor-tissue origin confined to the porta hepatis 3 and 5 months after OLT. Both patients were administered cyclosporine (CyA) and prednisone as primary immunosuppression. One patient was administered basiliximab as induction therapy. Neither patient had CyA trough levels greater than 250 ng/mL. Both patients were treated with a hepatojejunostomy, 75% reduction in immunosuppression therapy, and acyclovir. One patient had complete involution of the tumor, and the second patient had an 80% reduction of the tumor at the 2-year follow-up visit. This report illustrates the need to consider localized lymphoma post-OLT as a cause of obstructive jaundice even within the first 6 months after surgery. Aggressive reduction of immunosuppression in conjunction with acyclovir remains a highly effective therapy.

Indeterminate fibrohistiocytic lesions of the skin: is there a spectrum between dermatofibroma and dermatofibrosarcoma protuberans?

Routine histology and immunohistochemistry can usually distinguish dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP). DF generally expresses factor XIIIa whereas DFSP generally expresses CD34. The authors report 10 cutaneous fibrohistiocytic lesions combining clinical, histologic, and immunohistochemical features of both DF and DFSP. The lesions had an average size of 1.2 cm (range, 0.4-2.7 cm), and occurred on the trunk (n = 6), extremities (n = 3), and face (n = 1) of four men and six women (average age, 30.6 yrs; age range, 15-50 yrs). Eight lesions exhibited acanthosis and densely cellular fascicles with focal storiform areas. All had keloidal collagen, infiltrated the subcutis in a honeycomb pattern, and had low mitotic counts (0 to 4 mitoses per square millimeter). All were diffusely immunoreactive for factor XIIIa (30%-60% of the neoplastic cells) as well as CD34 (20%-70%). This series raises the possibility of a biologic spectrum between DF and DFSP; however, double-immunolabeling studies showed no notable coexpression of factor XIIIa and CD34 by individual cells, suggesting coexistence of two different cellular populations. After an average follow up of 22.3 months (range, 10-46 mos) in six cases, a single recurrence was documented. The ambiguous histologic features and the potential for local recurrence suggest that performing a complete excision may be prudent in these diagnostically indeterminate lesions.

The pathology of liver-localized post-transplant lymphoproliferative disease: a report of three cases and a review of the literature.

Post-transplantation lymphoproliferative disease (PTLD) is a complication of solid organ transplantation that is typically of B-cell origin and associated with Epstein-Barr virus (EBV). In patients receiving orthotopic liver transplantation (OLT) and treated with cyclosporin A. PTLD typically presents between 6 and 17 months post-transplantation as a systemic illness with involvement of the hepatic graft in a minority of cases. A small number of cases of biopsy-proven PTLD arising in the hepatic graft and limited to the liver and periportal structures have been previously reported. This report describes three additional cases of liver-localized PTLD and reviews similar cases in the literature. The donor/host origin of PTLD may have prognostic significance because the two cases in this report that are of donor origin had different clinical and pathologic features compared with the case of host origin. A rapid PCR-based technique for determining the origin of PTLD is described.

Evaluation of an automated technique for assessment of marrow engraftment after allogeneic bone marrow transplantation using a commercially available kit.

Several methods have been used to evaluate engraftment after allogeneic bone marrow transplantation (BMT). We assessed the usefulness of a multiple short tandem repeat (STR) amplification kit combined with a capillary electrophoresis unit for DNA identity analysis in the evaluation of engraftment after BMT. For 17 of 18 patients, at least 1 locus showed unique alleles for the donor and the recipient. In all cases, at least 1 locus was informative for the presence of small amounts of recipient DNA. The results from STR analysis were the same as Southern blot analysis in 14 of 17 cases. Differences included mixed chimerism detected only with STR analysis, informative loci present only with STR analysis, and informative loci present only with Southern blot analysis (1 case each). By using mock mixed chimeras, minor populations of 5% were detected routinely in all loci using the kit manufacturer's default protocol. By increasing the amount of amplified DNA, minor populations of 1% were detected in all cases but not in all loci. This single reaction technique provides for faster results, reduced workforce needs, and greater sensitivity than traditional Southern blot.

Autopsy findings in umbilical cord blood transplant recipients.

Human umbilical cord blood stem cells have been used to reconstitute hematopoiesis in patients with malignant and nonmalignant diseases. The immunologic immaturity of cord blood cells confers peculiar characteristics to these hematopoietic precursors. Autopsy reports from January 1, 1988, through June 30, 1998, were searched for patients who had received an umbilical cord blood transplant (UCBT). Thirty-two patients (19 male, 13 female) were identified with a mean age at autopsy of 13.0 years with a range from 1 to 52 years. Most patients (24) underwent UCBT for treatment of a malignant neoplasm, while the remainder were treated for immunodeficiencies (4), Lesch-Nyhan syndrome (2), Hurler syndrome (1), and Diamond-Blackfan syndrome (1). Sixteen patients had at least 1 infectious complication, and 8 patients had multiple infections. Organisms included mycoses (7 patients), viruses (8 patients), bacteria (3 patients), and Toxoplasma (2 patients). Hemorrhagic complications, such as intra-alveolar hemorrhage and gastrointestinal tract hemorrhage, were found in 24 patients. Other frequent findings at autopsy included diffuse alveolar damage (15 patients), hepatic veno-occlusive disease (11 patients), and acute or chronic graft-vs-host disease (9 patients). Patients who have received UCBT represent a unique population of immunosuppressed patients. Infectious and hemorrhagic complications frequently are encountered at autopsy, and pathologists performing autopsies on these patients should be alert to unusual pathogens.

Quantitation of intraepidermal T-cell subsets in formalin-fixed, paraffin-embedded tissue helps in the diagnosis of mycosis fungoides.

Differentiation between mycosis fungoides (MF) and cutaneous inflammatory processes can usually be made on clinical and histologic grounds. In difficult cases, immunohistochemical studies can be helpful since MF infiltrates usually contain a predominance of CD4+ lymphocytes, while most inflammatory lesions usually have a mixture of CD4+ and CD8+ lymphocytes. However, this determination has traditionally required the use of frozen tissue, thus severely limiting its usefulness. Recently, antibodies that differentially label CD4+ and CD8+ lymphocytes in formalin-fixed, paraffin-embedded tissue have become available (OPD4 and C8/144B respectively, DAKO (Carpinteria, CA, USA). This study tests the utility of these antibodies in the pathologic diagnosis of MF and inflammatory lesions with significant exocytosis. In 9 cases of MF for which both frozen and fixed tissues were available for comparison, the OPD4+ cell count in fixed tissue was significantly lower than the Leu-3a+ cell count in frozen tissue. Also, the C8/144B+ cell count in fixed tissue was higher than the Leu-2a+ cell count in frozen tissue, although this difference was not significant statistically. In a larger series for which only fixed tissue was available, epidermal CD4:CD8 ratios were significantly greater in 23 MF cases (mean 4.0+/-4.76) than in 35 inflammatory cases (mean 0.6+/-0.42; p = 0.001). Thus, although the studied antibodies appear to detect different epitopes in frozen versus paraffin-embedded tissue, demonstration of an elevated CD4:CD8 ratio in fixed tissue supports the diagnosis of MF, and is a helpful adjunct to routine histopathology.

Primary central nervous system lymphomas: a 30-year experience at a single institution.

Primary central nervous system lymphoma (PCNSL) is a rare disease that has been increasing in frequency. Clinical, histologic, and immunohistochemical data from 64 cases of PCNSL seen at Duke University Medical Center since 1968 were reviewed and tumors were classified using the REAL classification system. Thirty-two patients were male and 32 were female, with a mean age of 57.1 years, ranging from 16 to 82 years. Large B-cell lymphoma represented overwhelming the majority of PCNSL, accounting for 81% of all cases. Phenotypic T-cell lymphomas were rare with only two cases over the course of the study. Epstein-Barr virus was detected only in the immunocompromised patients and was identified in 75% of those immunocompromised patients who were tested. Overall survival was poor with a mean survival of 357 days and median survival of 158 days. One- and three-year survival rates were 29.6% and 7.8%, respectively. Type of treatment, duration of symptoms, site of lesion, and histologic subtype were not significant prognostic indicators, whereas concurrent immunosuppression was the strongest predictor of poor outcome. In AIDS patients (which accounted for 21.9% of the study group), the median survival was 65 days, which was significantly different than that seen in the immunocompetent group of 217 days (P = .001).

The mouse H-2A region influences the envelope gene structure of tumor-associated murine leukemia viruses.

C57BL/10 (B10) strains congenic at the mouse major histocompatibility locus (H-2) were injected with a modified ecotropic SL3-3 murine leukemia virus (MuLV) to determine the effect of the H-2 genes on the envelope gene structure of recombinant MuLVs. All tested strains rapidly developed T-cell lymphomas, and recombinant proviruses were detected in the tumor DNAs by Southern blot. The B10.D2 (H-2d), B10.Br (H-2k), B10.Q (H-2q), and B10.RIII (H-2r) strains exhibited a TI phenotype in which almost all tumors contained type I recombinants. These recombinants characteristically acquire envelope gene sequences from the endogenous polytropic viruses but retain the 5' p15E (TM) gene sequences from the ecotropic virus. The parental B10 (H-2b) strain, however, had a novel phenotype that was designated NS for nonselective. Only 30% of the B10 tumors had detectable type I recombinants, whereas a proportion of the others appeared to contain type II recombinants that lacked the type I-specific ecotropic p15E gene sequences. Studies of other B10 congenic strains with hybrid H-2 loci and selected F1 animals revealed that the NS phenotype was regulated by a dominant gene(s) that mapped to the A region of H-2b. These results demonstrate that a host gene within the major histocompatibility complex can influence the genetic evolution of pathogenic retroviruses in vivo.

Generation and pathogenicity of an NB-tropic SL3-3 murine leukemia virus.

A 428-base pair region of the gag gene of a molecular clone of the SL3-3 murine leukemia virus (MuLV) was replaced with allelic sequences that contain the NB-tropic determinants of the Moloney MuLV. SL3-3NB, the ecotropic virus derived from this modified clone, rapidly induced T-cell lymphoblastic lymphomas in the Fv-1n mouse strains CWD and NIH Swiss and the Fv-1b strain, B10.Br. By Southern blot assay, each of the CWD tumors and all but one of the B10.Br tumors that were tested contained recombinant proviruses. The envelope genes of the B10.Br recombinant viruses retained the SL3-3NB 5' p15E (TM) gene sequences (type I env), whereas the CWD recombinants did not (type II env). The production of type I env recombinants by B10.Br mice is a characteristic that is shared with other mouse strains that express the H-2k haplotype. The results indicate that the inserted Moloney virus gag sequences conferred NB-tropism to SL3-3NB and did not interfere with the expression of SL3-3 pathogenic determinants or the formation of recombinant viruses.

An increase in disease latency is associated with a host-dependent selection for recombinant murine leukemia viruses with substitutions in the p15E (TM) gene.

The genomes of recombinant murine leukemia viruses recovered from HRS/J (type I env recombinants) and CWD (type II env recombinants) mice have distinct envelope gene structures. To better understand the biologic significance of these differences, we examined the differences in the responses of HRS/J and CWD mice to inoculation with an oncogenic type II env recombinant. The CWD recombinant accelerated the onset of lymphoma in both strains, but the disease latency in the HRS/J mice was about 2 months longer. Analysis of the recombinant viruses in the HRS/J tumors revealed that the injected type II env recombinant had recombined in vivo with the endogenous ecotropic viruses to generate secondary recombinants with type I envelope genes. In another set of experiments, comparison of complete or partial DNA sequences of the envelope genes from six recombinant proviruses confirmed that the origins of the sequences that encode an amino-terminal region of the TM envelope protein, p15E, distinguish type I envelope genes from type II. Taken together with the results of previous studies, these observations suggest that the differences in the responses of HRS/J and CWD mice to the oncogenic type II env recombinant resulted from an interaction between the viral TM protein and a host factor expressed in HRS/J mice.