Primary cutaneous Hodgkin-like polymorphic post-transplant lymphoproliferative disorder.

Post-transplant lymphoproliferative disorder (PTLD) is an uncommon complication after solid-organ transplants and hematopoietic stem cell transplants. Isolated involvement of the skin without systemic involvement in PTLD is extremely rare. Primary cutaneous PTLD is generally categorized as either cutaneous T-cell lymphoma or cutaneous B-cell lymphoma, with variable Epstein-Barr virus (EBV) positivity. Herein, we describe an exceedingly uncommon case of a primary cutaneous Hodgkin-like polymorphic PTLD. A man in his 60s, with a history of kidney transplant, presented with a 5-week history of two indurated plaques. Clinical, histologic and immunohistochemical findings were consistent with primary cutaneous Hodgkin-like polymorphic PTLD. Reduction in immunosuppression led to resolution of his lesions. This case highlights a rare case of primary cutaneous Hodgkin-like PTLD and increases awareness of this uncommon post-transplant complication. It also underscores the importance of collaboration between dermatology, hematology, dermatopathology and hematopathology in order to diagnose challenging cases.

TLS-ERG leukemia fusion protein deregulates cyclin-dependent kinase 1 and blocks terminal differentiation of myeloid progenitor cells.

TLS-ERG fusion protein is derived from the t(16;21) translocation found in human myeloid leukemia. Here, we show that retroviral transduction of TLS-ERG confers a growth advantage to L-G myeloid progenitor cells and blocks terminal differentiation. We found that the level of cyclin-dependent kinase 1 (Cdk1) protein was significantly decreased in controls but unchanged in TLS-ERG-expressing cells after granulocyte colony-stimulating factor treatment or interleukin-3 withdrawal. Injection of TLS-ERG-expressing L-G cells induced rapid development of a leukemia-like disease in syngeneic mice. Through site-directed mutagenesis, we showed that transformation and deregulation of Cdk1 by TLS-ERG require an intact ets DNA-binding domain within the fusion protein. Interestingly, treatment of TLS-ERG-expressing L-G cells with 5-aza-2'-deoxycytidine (Decitabine) or trichostatin A resulted in down-regulation of Cdk1 and induction of terminal differentiation. To investigate whether Cdk1 deregulation is indeed responsible for transformation by TLS-ERG, we constructed lentiviral vectors for delivery of Cdk1 mutants and small interfering RNA (siRNA). Both dominant-negative inhibition and siRNA knockdown of Cdk1 were able to restore the ability of TLS-ERG-expressing L-G cells to undergo terminal differentiation. In addition, siRNA knockdown of Cdk1 in YNH-1 cells derived from a t(16;21) acute myelogenous leukemia patient also resulted in terminal differentiation. As restoration of terminal myeloid differentiation to TLS-ERG cells is dependent on cell cycle arrest, our findings suggest an important role for Cdk1 in cellular transformation and may be useful in the search for new treatments of TLS-ERG-associated myeloid leukemia.

Attitudes and Beliefs of Pathology Residents Regarding the Subspecialty of Clinical Chemistry: Results of a Survey.

CONTEXT: -Previous studies suggest that training in pathology residency programs does not adequately prepare pathology residents to become competent in clinical chemistry. OBJECTIVES: -To define the beliefs of pathology residents in the United States regarding their preparation for practicing clinical chemistry in their career, their attitude toward the discipline, and the attractiveness of clinical chemistry as a career. DESIGN: -The residents of all pathology residency programs in the United States were given the opportunity to participate in an online survey. RESULTS: -Three hundred thirty-six pathology residents responded to the survey. Analysis of the survey results indicates that pathology residents are more likely to believe that their income may be lower if they select a career that has a clinical chemistry focus and that their faculty do not value clinical chemistry as much as the anatomic pathology part of the residency. Residents also report that clinical chemistry is not as enjoyable as anatomic pathology rotations during residency or preferable as a sole career path. A large proportion of residents also believe that they will be slightly prepared or not prepared to practice clinical chemistry by the end of their residency and that they do not have enough background and/or time to learn clinical chemistry during their residency programs to be able to practice this specialty effectively post graduation. CONCLUSIONS: -Our survey results suggest that many pathology residents do not have a positive attitude toward clinical chemistry and do not experience a supportive learning environment with an expectation that they will become competent in clinical chemistry with a residency alone.

Statistical Literacy Among Academic Pathologists: A Survey Study to Gauge Knowledge of Frequently Used Statistical Tests Among Trainees and Faculty.

CONTEXT: -Statistical literacy can be defined as understanding the statistical tests and terminology needed for the design, analysis, and conclusions of original research or laboratory testing. Little is known about the statistical literacy of clinical or anatomic pathologists. OBJECTIVE: -To determine the statistical methods most commonly used in pathology studies from the literature and to assess familiarity and knowledge level of these statistical tests by pathology residents and practicing pathologists. DESIGN: -The most frequently used statistical methods were determined by a review of 1100 research articles published in 11 pathology journals during 2015. Familiarity with statistical methods was determined by a survey of pathology trainees and practicing pathologists at 9 academic institutions in which pathologists were asked to rate their knowledge of the methods identified by the focused review of the literature. RESULTS: -We identified 18 statistical tests that appear frequently in published pathology studies. On average, pathologists reported a knowledge level between "no knowledge" and "basic knowledge" of most statistical tests. Knowledge of tests was higher for more frequently used tests. Greater statistical knowledge was associated with a focus on clinical pathology versus anatomic pathology, having had a statistics course, having an advanced degree other than an MD degree, and publishing research. Statistical knowledge was not associated with length of pathology practice. CONCLUSIONS: -An audit of pathology literature reveals that knowledge of about 12 statistical tests would be sufficient to provide statistical literacy for pathologists. On average, most pathologists report they can interpret commonly used tests but are unable to perform them. Most pathologists indicated that they would benefit from additional statistical training.

Differential expression and clinical significance of tyrosine-phosphorylated STAT3 in ALK+ and ALK- anaplastic large cell lymphoma.

PURPOSE: Recent data suggest that nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) activates signal transducers and activators of transcription 3 (STAT3) directly, and ALK expression correlates with STAT3 activation in non-Hodgkin's lymphomas. In this study, we evaluated comprehensively STAT3 activation status in anaplastic large cell lymphoma (ALCL) cell lines and pretreatment ALCL tumors. EXPERIMENTAL DESIGN: The study included five ALK(+)ALCL cell lines and 80 systemic ALCL tumors (31 ALK(+), 49 ALK(-)) that were formalin fixed and paraffin embedded. All 80 patients with systemic ALCL were treated with doxorubicin-based chemotherapy. The STAT3 activation status in cell lines was determined using Western blots and an antibody that reacts specifically with the phosphorylated tyrosine 705 of STAT3, pSTAT3(tyr705). In ALCL tumors, STAT3 was considered active when > or =20% of neoplastic cells show unequivocal nuclear immunostaining for pSTAT3(tyr705). RESULTS: All five ALK(+)ALCL cell lines showed strong pSTAT3(tyr705) expression on Western blots. In systemic ALCL, STAT3 activation was detected in 49 of 80 (61%) ALCL tumors: 26 of 31 (84%) ALK(+) tumors and 23 of 49 (47%) ALK(-) tumors. ALK expression correlated significantly with STAT3 activation (P < 0.0001). Clinical follow-up data were available for 72 patients. In the ALK(-) group, the lack of STAT3 activation correlated with a favorable 5-year overall survival (P = 0.0076) but not failure-free survival. In the ALK(+) group, patients with inactive STAT3 showed a trend toward longer overall survival (P = 0.09) and failure-free survival (P = 0.19). Importantly, all five ALK(+) ALCL patients with inactive STAT3 survived without treatment failure after a median follow-up of 83 months. CONCLUSIONS: STAT3 activation correlates with but is not strictly dependent on ALK expression in ALCL. Lack of STAT3 activation appears to correlate with a favorable clinical outcome in ALCL.

Bone marrow involvement in patients with nodular lymphocyte predominant Hodgkin lymphoma.

The significance of bone marrow involvement in patients with nodular lymphocyte predominant Hodgkin lymphoma is unknown. Of 275 patients diagnosed as lymphocyte predominant Hodgkin lymphoma at our institution (1983-2003), we identified 7 patients with purely nodular disease in the diagnostic lymph node biopsy specimen who also had bone marrow involvement. The latter was detected at the time of initial diagnosis in four patients, after one cycle of chemotherapy in one patient, and at relapse in two patients. There were six men and one woman with a median age of 37 years (range, 25-47 years). In all cases, the bone marrow was involved by large B cells, representing <10% of all cells, associated with a prominent T-cell and histiocytic background. All patients had laboratory, radiologic, and/or morphologic evidence of aggressive disease at the time of detection of bone marrow involvement. At last follow-up, four patients had died of their disease and three were alive following therapy. In conclusion, a small subset of patients in whom lymph node biopsy shows nodular lymphocyte predominant Hodgkin lymphoma with a purely nodular pattern also may have lymphoma in the bone marrow. Bone marrow involvement is associated with laboratory, radiologic, or morphologic evidence of aggressive disease and poor prognosis. Although the best terminology for these bone marrow lymphomas is uncertain, the aggressive clinical behavior of these neoplasms supports the need for intensive therapy.

Differences in CD33 intensity between various myeloid neoplasms.

We measured the concentration of CD33 antigen on the surface of cells in 315 bone marrow (BM) samples and 114 corresponding peripheral blood (PB) samples from patients with various leukemias (acute myeloid leukemia [AML], chronic myelogenous leukemia [CML], myeloproliferative disorder [MPD] other than CML, myelodysplastic syndrome [MDS]) and from control subjects. Overall CD33 intensity in total CD33+ cells was significantly higher in BM than in PB. CD33 intensity in total BM CD33+ cells differed significantly with the type of disease. The median number of CD33 molecules per cell was highest in AML, followed by MDS, CML, and control subjects and lowest in MPD. When only CD34+/CD33+ cells were examined, CD33 molecules per cell were highest in CD34+ cells in AML and lowest in MPD (P = .027). Patients with AML or MDS younger than 60 years had significantly higher intensity of CD33 expression on CD34+ cells than patients 60 years or older. Levels of CD33 intensity did not correlate with cytogenetics in patients with AML or MDS. There was no correlation between CD33 intensity and response to therapy or overall survival in 35 patients treated with protocols including Mylotarg. These data demonstrate variation in CD33 intensity between various leukemias.

Prevalence and types of misrepresentation of publication record by pathology residency applicants.

CONTEXT: Publication misrepresentation among residency applicants has been demonstrated in various specialties. This study examines the prevalence of publication misrepresentation among US-trained and non-US-trained pathology residency applicants. OBJECTIVE: To determine the prevalence of publication misrepresentation in the pathology applicant pool at our institution, to compare the rates of misrepresentation among US-trained and non-US-trained applicants, and to compare results to published results from other medical specialties. DESIGN: All peer-reviewed journal articles reported on applications to our program in 2010 and 2011 were examined for veracity. Applications from current or past trainees and applications with unverifiable manuscripts were excluded. The type of misrepresentation and the country in which the applicant trained were recorded. RESULTS: Seven hundred applications were reviewed. Of 319 (46%) reported publications, 25 were from US graduates (8%) and 294 (92%) were from non-US graduates. Eighty-six applications were excluded owing to unverifiable manuscripts. Publication misrepresentations were found in 42 (18%) of the remaining 233 applications. The most common misrepresentations were omission of authors (69%), nonauthorship (14%), and self-promotion on the author list (12%). A significantly higher percentage of foreign medical graduates listed publications (P < .001). The misrepresentation rate by foreign graduates (19%) did not differ significantly from that of US-trained graduates (13%) (P = .45). CONCLUSIONS: Publication misrepresentation was present among pathology residency applicants. Similar rates were seen among US and non-US applicants. Percentages of misrepresentation among applicants to our pathology program and applicants to other medical specialties (18% and 17%, respectively) were comparable.

Activation status of the JAK/STAT3 pathway in mantle cell lymphoma.

CONTEXT: Signal transducer and activator of transcription 3 (STAT3) is oncogenic, and we previously found evidence of constitutive STAT3 activation in a relatively small number of frozen mantle cell lymphoma (MCL) cell tumors. OBJECTIVES: To comprehensively survey the activation and phosphorylation status of STAT3 in MCL and to assess if STAT3 activation in these tumors is due to cytokine stimulation by examining the phosphorylation and activation status of Janus kinase (JAK), the physiologic activator of STAT3. DESIGN: We evaluated 43 formalin-fixed, paraffin-embedded MCL tumors using immunohistochemistry and phospho-specific antibodies against STAT3 and JAK. RESULTS: There were 37 small cell and 6 blastoid cases. There was heterogeneous expression of phospho-STAT3 (pSTAT3), with 23 negative cases (53%), 12 weakly positive cases (28%), and 8 strongly positive cases (19%). JAK3 was the only member detectable in 3 MCL cell lines, and immunoprecipitation data showed a relatively low level of tyrosine phosphorylation of JAK3 in these cells. Using immunohistochemistry, phospho-JAK3 (pJAK3) was detectable in 18 (44%) of 41 MCL tumors examined, and pJAK3 expression correlated with that of pSTAT3 (P = .008). A notable exception to this correlation was seen in the blastoid variant, since 4 (67%) of 6 blastoid cases were pSTAT3 positive but pJAK3 negative. CONCLUSIONS: We have confirmed our previous finding that STAT3 is constitutively activated in MCL tumors, with an overall frequency of 47% in this series. STAT3 activation in the small cell but not the blastoid variant of MCL is likely mediated by JAK3.

Expression of c-kit proto-oncogene product in breast tissue.

The proto-oncogene c-kit encodes a transmembrane tyrosine kinase growth factor receptor. Stem cell factor, the receptor ligand, plays an important role in the development of certain neoplasms. c-kit is selectively and competitively bound by STI-571, a newly developed tyrosine kinase inhibitor. Several investigators report conflicting results concerning its expression, especially in malignant breast lesions. The objective of this study was to better characterize the expression of c-kit within the spectrum of breast epithelium (normal breast epithelium, nonneoplastic lesions, and breast carcinoma). Seventy-seven randomly selected breast tissue samples, each containing normal breast epithelium (21), invasive breast carcinoma (41), in situ breast carcinoma (29), papilloma (8), fibroadenoma (5), fibrocystic change (11), and/or metastatic breast carcinoma (4), were immunostained with polyclonal rabbit antihuman c-kit (Dako, Carpenteria, CA) at a dilution of 1:200. The staining was interpreted as negative if no cells were immunoreactive, weak positive if 5% of the cells were immunoreactive, and positive if more than 5% of the cells were immunoreactive. Appropriate positive and negative controls were used. The observed staining was cytoplasmic, with highlighting of the nuclear membrane. Normal breast epithelium was positive in all cases. More than half of the cases of hyperplastic changes and benign neoplasms (fibroadenoma and papilloma) were positive. Only 10% of invasive and in situ carcinomas showed positivity for c-kit. c-kit is consistently expressed in normal breast epithelium, variably expressed in benign breast lesions, and poorly expressed in breast carcinoma. These data suggest that c-kit may play a role in breast tumor progression and may therefore have diagnostic, prognostic, and therapeutic implications.

A prognostic model for survival in chronic lymphocytic leukaemia based on p53 expression.

As the abnormal expression of p53 protein is prognostically significant in some human cancers, its significance in patients with B-cell chronic lymphocytic leukaemia (CLL) was assessed. Two investigators evaluated the percentage of bone marrow mononuclear cells that stained for p53, using biopsies stained with anti-p53 monoclonal antibody (DO-7), and graded the degree of staining (0, +, ++, +++). Samples from a cohort of 90 patients with CLL were studied (median age 60 years, range 30-89 years; 57 patients were (63%) previously untreated, 22 patients (24%) had received one or two prior regimens, 11 patients had received (12%) three to seven regimens. The overall percentage of cells positive for p53 staining was a median of 43 (range 1-88). No investigator effect was detected either in overall percentage cells rated p53 positive or on the degree of staining (Pearson's correlation coefficient 0.980, P-value < 0.001). A Cox proportional hazards model showed that the percentage of ++ and +++ p53-positive cells correlated with various prognostic factors in CLL (P < 0.0001). A multivariate model incorporating prior therapy, Rai stage, beta2 microglobulin (beta2M) and p53 expression showed that only the percentage of p53-positive cells and beta2M were predictive of survival, and enabled the development of a highly predictive model of survival based on these two parameters.