Mild changes of hepatic nodular regenerative hyperplasia may cause portal hypertension and be visible on reticulin but not hematoxylin and eosin staining.

Nodular regenerative hyperplasia (NRH) can manifest as alternating parenchymal compression/expansion on hematoxylin and eosin (H&E) staining and as reticulin collapse/nodularity on reticulin staining. Histologic diagnosis can be challenging, especially when there is mild disease and on limited biopsy samples. We reviewed clinical and histologic parameters in a large series of NRH. We identified 60 liver specimens convincingly showing changes of NRH and reviewed them for clinical (age, sex, symptoms, lab values, portal hypertension [PHTN], NRH etiology) and histologic (inflammation, sinusoidal dilation, cholestasis, architectural change, portal vascular abnormalities, degree of changes on reticulin) parameters. The cases came from 28 women and 32 men (median age: 54 years). Most (55, 92%) were biopsies. Thirty patients were symptomatic. Forty-five cases showed mild NRH changes on reticulin; 24 of these (53%) showed them on H&E as well. Fifteen demonstrated well-developed changes on reticulin, which were always seen on H&E as well. Sinusoidal dilation was commonly observed in both of these subgroups (88% overall). Portal vascular abnormalities were seen in 33%. Well-developed NRH was diffuse more often than mild NRH (53% vs. 4%, P < 0.0001). Twenty-nine patients had clinically confirmed or likely PHTN. Of these, 21 showed mild and 8 showed well-developed NRH changes; only 3 had concomitant advanced fibrosis. Chemotherapy was the most frequent known cause of NRH; 30 patients lacked any definite etiology. NRH can be difficult to diagnose on biopsy, particularly since mild changes may be visible on reticulin but not H&E; even these patients can have PHTN. Additionally, NRH is often idiopathic, potentially lowering clinical and pathologic suspicion. Pathologists should have a low threshold for ordering reticulin stains, especially when a patient is known to have PHTN. Sinusoidal dilation, while nonspecific, commonly accompanies NRH.

Biopsies of hepatocellular carcinoma with no reticulin loss: an important diagnostic pitfall.

The reticulin stain is a critical diagnostic aide used to differentiate benign hepatocellular proliferations from well differentiated hepatocellular carcinoma (HCC). Rarely, however, hepatocellular carcinomas do not show definitive loss of reticulin in liver biopsy specimens. To study this group of tumors, 11 HCC with no reticulin loss in 10 patients were collected and studied. Analysis of demographics showed a typical enrichment for men with a typical age for HCC presentation of 69 ± 7 years for adults. The background livers showed advanced fibrosis or cirrhosis in 6 of 6 cases with available information. The tumors were all well differentiated. Cytological atypia was mild and consisted of very mild nuclear atypia (8 cases), mild increase in N:C ratio (3 cases), and pseudorosette formation (4 cases). The cytological/architectural atypia was insufficient in isolation to diagnose HCC. Additional studies, however, showed an increased Ki-67 proliferative rate (N = 10/10 stained cases). The Ki-67 proliferative rate was estimated to be between 5 and 10% in all tested cases and was clearly increased from adjacent liver at low power. Glypican 3 positivity (4 tumors) and alpha fetoprotein (AFP) (1/8 stained cases) positivity also helped make the diagnosis of HCC. Morphologically, the HCC had conventional morphology with five showing steatosis/steatohepatitic features and one showing intratumoral fibrosis. A control group of macroregenerative/dysplastic nodules showed no increase in Ki-67 proliferation and no staining for glypican 3. These findings highlight an important diagnostic pitfall: rare HCC show no reticulin loss on biopsy. In these challenging cases, additional findings are useful to make a diagnosis of HCC: increased Ki-67 and positive staining for aberrant expression of proteins such as glypican 3 or AFP.

Reticulin staining pattern in the differential diagnosis of benign parathyroid lesions.

AIM: A reticulin staining pattern (RSP) can be used for the differential diagnosis of endocrine gland lesions, as in the adrenal and hypophysis glands. We aimed to use RSP for the differential diagnosis of parathyroid gland lesions. MATERIALS AND METHODS: In this study, we evaluated 97 parathyroid lesions in 85 patients, as well as 29 normal parathyroid glands. All sections were stained with a silver impregnation-based kit for the reticulin stain. The RSPs were classified as short thick fiber-, anastomosing- and nodular/alveolar-pattern. The dominant pattern was accepted as being greater than 50% in each section. RESULTS: Short thick fibers and anastomosing and nodular RSPs were seen in adenomas, but there was no alveolar pattern. Although nodular/alveolar patterns were seen in focal areas in hyperplasia, they never became the dominant pattern. Nodular dominant RSPs were seen in adenomas; however, nodular RSPs were not seen in hyperplasia in a dominant pattern (p = 0.049). While short thick fibers were not seen in normal glands, they could be seen in adenomas (p < 0.001) and in hyperplasia (p < 0.001). CONCLUSION: RSPs can be used in the differential diagnosis of parathyroid lesions. While short thick reticular fibers support adenomas and hyperplasia rather than normal tissue, a nodular dominant pattern supports adenomas rather than hyperplasia.

Combined multiphoton imaging and biaxial tissue extension for quantitative analysis of geometric fiber organization in human reticular dermis.

The geometric organization of collagen fibers in human reticular dermis and its relationship to that of elastic fibers remain unclear. The tight packing and complex intertwining of dermal collagen fibers hinder accurate analysis of fiber orientation. We hypothesized that combined multiphoton microscopy and biaxial extension could overcome this issue. Continuous observation of fresh dermal sheets under biaxial extension revealed that the geometry of the elastic fiber network is maintained during expansion. Full-thickness human thigh skin samples were biaxially extended and cleared to visualize the entire reticular dermis. Throughout the dermis, collagen fibers straightened with increased inter-fiber spaces, making them more clearly identifiable after extension. The distribution of collagen fibers was evaluated with compilation of local orientation data. Two or three modes were confirmed in all superficial reticular layer samples. A high degree of local similarities in the direction of collagen and elastic fibers was observed. More than 80% of fibers had directional differences of ≤15°, regardless of layer. Understanding the geometric organization of fibers in the reticular dermis improves the understanding of mechanisms underlying the pliability of human skin. Combined multiphoton imaging and biaxial extension provides a research tool for studying the fibrous microarchitecture of the skin.

Granulosa Cell Tumors of the Ovary With Prominent Thecoma-like Foci: A Report of 16 Cases Emphasizing the Ongoing Utility of the Reticulin Stain in the Modern Era.

Sixteen adult granulosa cell tumors which had conspicuous zones of cells with pale cytoplasm imparting a resemblance to thecoma are reported. The neoplasms occurred in patients from 38 to 86 yr of age, the majority being over 55 yr of age. Ten tumors were incidental findings, the remainder being associated with symptoms or signs related to an adnexal mass. All the tumors were unilateral, typically small, usually under 5 cm, with only 3 being larger. With 1 exception they were uniformly solid and were typically entirely or focally yellow on sectioning. Microscopic examination typically showed a nodular pattern of growth constituted by cells with moderate to abundant pale cytoplasm; the cells resembled those seen in most thecomas. The nodules occasionally became confluent and focally a diffuse pattern was seen. Typical foci of adult granulosa cell neoplasia in the form of foci of conspicuous epithelial differentiation were absent or rare in most cases but were seen in subtle form in 6 cases and overtly in 3. A few tumors had other features seen in some thecomas, hyaline plaques, sclerosis, and calcification. Reticulin stains were examined in 13 cases and showed that the thecoma-like foci exhibited a dearth of reticulum indicating that those areas were predominantly of granulosa cell nature. Most adult granulosa cell tumors have cells with scant cytoplasm; occasional tumors have abundant eosinophilic cytoplasm, so-called luteinized adult granulosa cell tumors. That some granulosa cell tumors have the cytoplasmic features described herein has occasionally been noted but the resemblance to thecoma has not been emphasized to the best of our knowledge and in the past such tumors may have been misdiagnosed as thecoma, the referral diagnosis in 6 of our cases. A reticulin stain is of crucial aid in indicating the epithelial nature of the thecoma-like foci in these cases. Given the small size of the majority of the tumors the distinction between a small adult granulosa cell tumor and thecoma does not have significant prognostic or therapeutic implications in most cases but awareness of this feature of a small subset of adult granulosa cell tumors is warranted. Our findings have import to the diagnosis of thecoma which is uncommon if strict criteria, including exclusion of granulosa tumors of the type described, are used.

Chronic Myelomonocytic Leukemia With Fibrosis Is a Distinct Disease Subset With Myeloproliferative Features and Frequent JAK2 p.V617F Mutations.

A subset of patients with chronic myelomonocytic leukemia (CMML) presents with significance myelofibrosis. In myelodysplastic syndromes, significant myelofibrosis has been associated with adverse outcomes and p53 dysregulation. However, in CMML the clinical and molecular correlates of significant myelofibrosis at presentation remain poorly understood. From a cohort of 651 CMML patients, we identified retrospectively 20 (3.1%) cases with moderate to severe reticulin fibrosis (CMML-F) detected at diagnosis, and we compared them to CMML patients without fibrosis (n=631) seen during the same period. Patients with CMML-F had a median age of 69.8 years (range, 24.8 to 91.2 y) and most (13; 65%) were men. Patients with CMML-F differed significantly from other CMML patients across the following parameters: white blood count, absolute monocyte count, serum lactate dehydrogenase level, splenomegaly, and bone marrow blast percentage. Notably, the frequency of JAK2 p.V617F mutation was higher in CMML-F patients compared with other CMML patients (P<0.001). Most CMML-F patients (12/20; 60%) had myeloproliferative CMML. Dysregulation of p53 was uncommon in CMML-F. CMML-F patients tended to have a shorter median overall survival compared with other CMML patients (P=0.079). Multivariate analysis using the Cox proportional hazards model showed an independent association between CMML-F and overall survival (P=0.047). In summary, unlike typical CMML, CMML-F is commonly associated with JAK2 p.V617F. The high frequency of myeloproliferative features and JAK2 p.V617F mutation, and the low frequency of p53 dysregulation, suggest that fibrosis in the context of CMML has a different pathogenesis from that previously reported in myelodysplastic syndrome.

Analysis of histological and immunohistochemical patterns of benign and malignant adrenocortical tumors by computerized morphometry.

Diagnosis of benign and purely localized malignant adrenocortical lesions is still a complex issue. Moreover, histology-based diagnosis may suffer of a moment of subjectivity due to inter- and intra-individual variations. The aim of the present study was to assess, by computerized morphometry, the morphological features in benign and malignant adrenocortical neoplasms. Eleven adrenocortical adenomas (ACA) were compared with 18 adrenocortical cancers (ACC). All specimens were stained with H&E, cellular proliferation marker Ki-67 and reticulin. We generated a morphometric model based on the analysis of volume fractions occupied by Ki-67 positive and negative cells (nuclei and cytoplasm), vascular and inflammatory compartment; we also analyzed the surface fraction occupied by reticulin. We compared the quantitative data of Ki-67 obtained by morphometry with the quantification resulting from pathologist's visual reading. The volume fraction of Ki-67 positive cells in ACCs was higher than in ACAs. The volume fraction of nuclei in unit volume and the nuclear/cytoplasmic ratio in both Ki-67 negative cells and Ki-67 positive cells were prominent in ACCs. The surface fraction of reticulin was considerably lower in ACCs. Our computerized morphometric model is simple, reproducible and can be used by the pathologist in the histological workup of adrenocortical tumors to achieve precise and reader-independent quantification of several morphological characteristics of adrenocortical tumors.

[Correlation between Bone Marrow Fibrous Proliferation and Prognosis of Acute Myeloid Leukemia].

OBJECTIVE: To investigate the correlation between the bone marrow fibrous proliferation and the prognosis of acute myeloid leukemia(AML). METHODS: The quantitative method was used to analyze the reticulin fiber density (RFD) of AML patients. the bone marrow sections from 39 primary AML patients and 35 normal controls were collected to compare the RFD between these 2 groups. The prognosis value of RFD for AML were estimated by using appropriate statistical analysis. RESULTS: RFD in primary AML was significantly higher than that in normal controls(2.41%±0.23% vs 1.14%±0.06%)(P<0.05). Relapse-free survival(RFS) analysis showed that the patients with RFD more than 1.68% indicated poor RFS, and the overall survival(OS) analysis showed that patients with RFD more than 2.66% indicated poor overall survival (P<0.05). Besides, there were no relationship between RFD and the BM blast count (r=0.01) and WBC counts (r=0.04) at diagnosis(P>0.05). CONCLUSION: The RFD in bone marrow is a high risk factor in poor prognosis of AML patients.

Rapid growth of mitotically active cellular fibroma of the ovary: a case report and review of the literature.

BACKGROUND: Mitotically active cellular fibroma (MACF) of the ovary, characterized by relatively high mitotic activity without severe atypia, represents a relatively new disease entity. MACF is categorized as a benign ovarian tumor. However, due to a limited number of case reports, its clinical and pathological features and optimum management remains largely undetermined. Herein, we report on a rare case of MACF that grew rapidly in size and was diagnosed on detailed pathological examination. CASE PRESENTATION: A 44-year-old Japanese woman, who detected a myoma-like lesion 1-year earlier, was referred to our hospital when the follow-up examination demonstrated that the mass had increased in size. Magnetic resonance imaging revealed a T1 isointense and T2 hyperintense tumor (11 cm in diameter) in the right pelvic cavity. Laparoscopy confirmed the presence of a right ovarian tumor and laparoscopic right adnexectomy was performed. The tumor cells consisted of dense cellular proliferations of spindle fibroblast-like cells without significant cytological atypia. The mitotic activity index was estimated at >15 mitotic figures per 10 high-power fields. Reticulin staining and FOXL2 mutation analysis excluded the possibility of an adult granulosa cell tumor, and the patient was diagnosed with a MACF of the ovary. CONCLUSIONS: To the best of our knowledge, we are the first to report on a case of rapid growth of a MACF of the ovary during follow-up. When an increase in the size of a solid ovarian mass is detected, a MACF should be considered as a differential diagnosis.

Are micromegakaryocytes specific for refractory cytopenia of childhood (RCC)? A study of 38 pediatric patients with thrombocytopenia unrelated to RCC.

BACKGROUND: Micromegakaryocytes (microMKs) are considered the most reliable dysplastic feature for myelodysplastic syndrome (MDS), particularly refractory cytopenia of childhood (RCC); there is no minimal threshold for the diagnosis of RCC. Since most RCC patients present with thrombocytopenia, the presence of microMKs should raise concern for MDS/RCC. This study attempted to investigate the prevalence of microMKs and associated marrow fibrosis in patients with thrombocytopenia unrelated to MDS/RCC and the need for establishing a threshold for microMKs for the diagnosis of MDS/RCC. DESIGN: Bone marrow biopsies of pediatric patients with thrombocytopenia unrelated to RCC were examined for microMKs and fibrosis by CD61 immunohistochemical and reticulin stains respectively. RESULT: Thirty eight patients (1-18 years old) were included: 33 immune thrombocytopenia (ITP), 3 chronic thrombocytopenia, and 2 inherited macrothrombocytopenia. Fourteen cases (37%) had microMKs; four cases showed increased marrow fibrosis associated with microMKs (two had ITP and two had macrothrombocytopenia). All patients are alive and none developed MDS (follow up: 3months to 4 years). CONCLUSION: MicroMKs can be seen in pediatric patients with thrombocytopenia unrelated to RCC. Hence the mere presence of microMKs is insufficient for the diagnosis of RCC in the pediatric population, and a quantitative threshold needs to be established.

Stress reticulocytes lose transferrin receptors by an extrinsic process involving spleen and macrophages.

As they mature into erythrocytes during normal erythropoiesis, reticulocytes lose surface transferrin receptors before or concurrently with reticulin. Exosome release accounts for most of the loss of transferrin receptors from reticulocytes. During erythropoietic stress, reticulocytes are released early from hematopoietic tissues and have increased reticulin staining and transferrin receptors. Flow cytometry of dually stained erythrocytes of mice recovering from phlebotomy demonstrated delayed loss of reticulin and transferrin receptors during in vitro maturation compared to in vivo maturation, indicating that an in vivo process extrinsic to the reticulocytes facilitates their maturation. Splenectomy or macrophage depletion by liposomal clodronate inhibited in vivo maturation of reticulocytes and increased the numbers of reticulin-negative, transferrin receptor-positive cells during and after recovery from phlebotomy. This reticulin-negative, transferrin receptor-positive population was rarely found in normal mice. Transmission electron microscopy demonstrated that the reticulin-negative, transferrin receptor-positive cells were elongated and discoid erythrocytes, but they had intracellular and surface structures that appeared to be partially degraded organelles. The results indicate that maturation of circulating stress reticulocytes is enhanced by an extrinsic process that occurs in the spleen and involves macrophage activity. Complete loss of reticulin with incomplete loss of surface transferrin receptors in this process produces a reticulin-negative, transferrin receptor-positive erythrocyte population that has potential utility for detecting prior erythropoietic stresses including bleeding, hemolysis and erythropoietin administration, even after recovery has been completed. Am. J. Hematol. 91:875-882, 2016. © 2016 Wiley Periodicals, Inc.

Problems and pitfalls in grading of bone marrow fibrosis, collagen deposition and osteosclerosis - a consensus-based study.

AIMS: In the era of potentially disease-modifying agents such as Janus kinase inhibitors, accurate grading and differentiation of bone marrow (BM) fibrosis has become more relevant to assess staging of disease and therapeutic effects. However, different fibrosis grading models have been used in the past without uniformity, including the proposal by the World Health Organization. Current scoring systems are based only on reticulin fibrosis. Therefore, additional assessment of collagen and the grade of osteosclerosis appear to be essential to discriminate all components of the complex BM fibrous matrix. METHODS AND RESULTS: We evaluated problems and pitfalls regarding staining techniques and the interpretation of reticulin fibrosis on a total of 352 samples. Furthermore, we propose a minor modification of the current grading and separate scoring for collagen deposition and osteosclerosis. Reproducibility of gradings was tested among 11 haematopathologists in a blinded assessment. Overall, the inter-rater reliability of all three grading systems ranged between 0.898 and 0.926. CONCLUSIONS: A standardized assessment of BM fibrosis with differentiation between reticulin, collagen and osteosclerosis is recommended to evaluate the various components of the fibrous matrix which may be delinked after therapy. In this regard, quality of staining and application of laboratory standards enable a highly reproducible scoring.

Evaluación sistemática de la biopsia de médula ósea en casos de sospecha de mielofibrosis primaria. Propuesta de informe diagnóstico estandarizado. Consenso de expertos de las SEAP/SEHH / Systematic evaluation and standardised reporting of cases with suspicion of primary myelofibrosis. Consensus of SEAP/SEHH hematopathology experts

Se ha elaborado un consenso aplicando la metodología Delphi para acordar cuál debe ser la sistemática de evaluación e información de las biopsias de médula ósea en las neoplasias mieloproliferativas crónicas, especialmente en casos de mielofibrosis primaria (MFP). Un panel de 10 expertos hematopatólogos ha elaborado un cuestionario que se ha remitido a 37 hematopatólogos con preguntas acerca de los datos clínicos, analíticos y moleculares a conocer en la fase pre-analítica, parámetros histopatológicos a evaluar y contenido del informe diagnóstico final. Se realizaron 2 rondas buscando un consenso mínimo del 70% para los parámetros imprescindibles y recomendables. A partir de los resultados del consenso se elabora y propone un prototipo de informe histopatológico para informar de manera homogénea y reproducible los casos de MFP (AU)

A consensus based on Delphi methodology was developed to produce a guide for the evaluation and reporting of bone marrow biopsies in patients with a clinical suspicion of myeloproliferative neoplasm with fibrosis. Ten expert haematopathologists formulated a questionnaire including: clinical and laboratory data required before regarding a biopsy suspicious for primary myelofibrosis (PMF), descriptive aspects to be reported and the main histopathological differential diagnoses to be considered. It was circulated among 37 hematopathologists and consensus was defined when more than 70% of the experts "strongly agreed" or "agreed" after two rounds. The recommendations gave rise to a proposal for a standardized diagnostic report form to aid in the diagnostic workup and homogeneous reporting of cases with a clinical suspicion of PMF (AU)

Image analysis of platelet derived growth factor receptor-beta (PDGFRß) expression to determine the grade and dynamics of myelofibrosis in bone marrow biopsy samples.

BACKGROUND: Myelofibrosis (MF) is characterized by accumulation of stromal cells and extracellular matrix. Progression of fibrosis is an important clinical issue and monitoring is required for new therapeutic approaches. Currently, the quantification is based on semiquantitative evaluation of reticulin silver stained slides. We recently reported that platelet derived growth factor receptor beta (PDGFRß) expression in fibroblasts is a useful marker of stromal activation. PDGFRß expression based scores represent significant differences in different MF grade which provides optimal source of quantification. In this study, slide-based measurements were performed to support correlations of PDGFRß expression with MF grade. METHODS: Scanned image tiles from 79 bone marrow samples (BM) with different MF grades were evaluated for PDGFRß-related IHC parameters. Following the determination of immunopositive (brown component) and total area (region of interest) of the BM, PDGFRß related image parameters were defined and evaluated in comparison with the classical reticulin based grading. RESULTS: Eight PDGFRß expression related image parameters showed excellent correlation with the MF grade (correlation coefficient ranging between 0.79 and 0.83) and with PDGFRß score (0.76-0.87). Despite the significant sample heterogeneity, the parameters showed significant differences between fibrotic and nonfibrotic cases and between mild and advanced fibrosis. Distribution of values within a particular specimen emphasizes the heterogeneity of bone marrow involvement which may cause difficulties in semiquantitative methods. CONCLUSIONS: Our results clearly demonstrated the correlation between MF and PDGFRß expression considering all relevant areas in BM samples. This method provides good basis for follow-up comparison of the fibrotic samples.

Complex karyotype in a polycythemia vera patient with a novel SETD1B/GTF2H3 fusion gene.

The patient had been diagnosed with polycythemia vera (PV) in 1999, at the age of 61, according to the criteria of the Polycythemia Vera Study Group (PVSG) on the basis of the increased red cell mass by isotope determination, normal oxygen saturation, low plasma erythropoietin level, presence of endogenous erythroid colonies (EEC), and splenomegaly. Histopathology of bone marrow biopsy was also consistent with polycythemia vera with no evidence of increased reticulin fibrosis. A karyotype analysis was not performed at that time. He had been treated initially with phlebotomies and then with hydroxyurea with the aim to obtain a better control of hematocrit; he was under low-dose aspirin. In 2009, 10 years after the diagnosis, while the patient was still being treated with hydroxyurea and phlebotomies, he noticed worsening of general conditions and fatigue, and the appearance of night sweats; he also reported that his spleen volume had increased rapidly in the past few months. He complained of severe pruritus especially after (but not limited to) a shower. He was referred to our center for further evaluation. At presentation, his blood counts were as follows: hemoglobin 157 g/L, hematocrit 54.7%, leukocytes 13.1 × 109 /L, platelets 238 × 109 /L, LDH 856 U/L (normal upper limit, 250 U/L). Blood film examination showed neutrophilia (8.9 × 109 /L) but immature myeloid cells and nucleated erythroblasts were absent. The spleen was 14 cm below the left costal margin, the liver was at 4 cm below the right costal margin. He was found to harbor the JAK2V617F mutation with an allele burden of 85% and the circulating CD34⁺ cell count was 14 × 106 /L. A bone marrow biopsy showed the presence of hyperplasia of myeloid and erythroid lineages, increased number of scattered megakarocytes without overt morphologic abnormalities; reticulin fibrosis was grade 1 according to the European classification. On these basis, we considered the patient as presenting the features of PV according to the 2008 WHO classification of myeloid neoplasms associated with grade 1 reticulin fibrosis.

JAK1/2 and Pan-deacetylase inhibitor combination therapy yields improved efficacy in preclinical mouse models of JAK2V617F-driven disease.

PURPOSE: The myeloproliferative neoplasm myelofibrosis is characterized by frequent deregulation of Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling, and JAK inhibitors were shown to reduce splenomegaly and ameliorate disease-related symptoms. However, the mutant clone and bone marrow fibrosis persist in the majority of patients. Using preclinical models, we explored whether JAK and pan-deacetylase inhibitor combination yielded additional benefits. EXPERIMENTAL DESIGN: The combination of the JAK1/2 inhibitor ruxolitinib and panobinostat was investigated using two different mouse models of JAK2(V617F)-driven disease. A Ba/F3 JAK2(V617F) cell-driven leukemic disease model was used to identify tolerated and efficacious doses. The drugs were then evaluated alone and in combination in a mouse model of myeloproliferative neoplasm-like disease based on transplantation of bone marrow transduced with a retrovirus expressing JAK2(V617F). Exposures were determined in blood and tissues, and phosphorylated STAT5 and acetylated histone H3 pharmacodynamic readouts were assessed in spleen and bone marrow. Histologic analysis was conducted on spleen and bone marrow, including staining of reticulin fibers in the latter organ. RESULTS: The combination of ruxolitinib and panobinostat was found to have a more profound effect on splenomegaly, as well as on bone marrow and spleen histology, compared with either agent alone, and the analysis of pharmacodynamic readouts showed that ruxolitinib and panobinostat have nonoverlapping and complementary effects. CONCLUSION: Combining JAK1/2 and pan-deacetylase inhibitors was fairly well tolerated and resulted in improved efficacy in mouse models of JAK2(V617F)-driven disease compared with the single agents. Thus, the combination of ruxolitinib and panobinostat may represent a promising novel therapeutic modality for myeloproliferative neoplasms.

The reticulin algorithm for adrenocortical tumor diagnosis: a multicentric validation study on 245 unpublished cases.

The pathologic diagnosis of adrenocortical carcinoma (ACC) still needs to be improved, because the renowned Weiss Score (WS) system has a poor reproducibility of some parameters and is difficult to apply in borderline cases and in ACC variants. The "reticulin algorithm" (RA) defines malignancy through an altered reticulin framework associated with 1 of the 3 following parameter: necrosis, high mitotic rate, and vascular invasion. This study aimed at validating the interobserver reproducibility of reticulin stain evaluation in an unpublished series of 245 adrenocortical tumors (61 adenomas and 184 carcinomas) from 5 Italian centers, classified according to the WS. Eight pathologists reviewed all reticulin-stained slides. After training, a second round of evaluation on discordant cases was performed 10 weeks later. The RA reclassified 67 cases (27%) as adenomas, including 44 with no reticulin alterations and 23 with an altered reticulin framework but lacking the subsequent parameters of the triad. The other 178 cases (73%) were carcinomas according to the above-mentioned criteria. A complete (8/8 pathologists) interobserver agreement was reached in 75% of cases (κ=0.702), irrespective of case derivation, pathologists' experience, and histologic variants, and was further improved when only those cases with high WS and clinically malignant behavior were considered. After the training, the overall agreement increased to 86%. We conclude that reticulin staining is a reliable technique and an easy-to-interpret system in adrenocortical tumors; moreover, it has a high interobserver reproducibility, which supports the notion of using such a method in the proposed 2-step RA approach for ACC diagnosis.

[Correlation of chromosome karyotype with dyshaematopoiesis and reticulin in myelodysplastic syndrome].

This study was purposed to explore the correlation of chromosome karyotype with dyshaematopoiesis and reticulin in myelodysplastic syndrome (MDS). The data of 202 MDS patients diagnosed and treated in the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed in term of chromosome karyotype, dyshaematopoiesis and reticulin detection results. The chromosome karyotypes were categorized according to the International Prognostic Scoring System (IPSS). The results showed that there was a positive correlation between chromosome karyotype grading and number of lineages with dyshaematopoiesis (r = 0.443, P < 0.05). The detected rates of multilineage dyshaematopoiesis in patients with good, intermediate and poor chromosome karyotypes were 44.4%, 71.4% and 96.3% respectively. There was a positive correlation between chromosome karyotype grading and reticulin grading (r = 0.451, P < 0.05). The positive rates of reticulin in patients with good grading, intermediate and poor chromosome karyotypes were 36.8%, 64.3% and 92.6% respectively. The detected rate of multilineage dyshaematopoiesis, number of lineages with dyshaematopoiesis, the positive rate of reticulin and reticulin grade in patients with poor karyotypes were higher than those in patients with intermediate or good chromosome karyotypes (separately P < 0.01). The above data in patients with intermediate chromosome karyotypes were higher than those in patients with good chromosome karyotypes (separately P < 0.01). It is concluded that the chromosome karyotype grading positively correlates with the number of lineages with dyshaematopoiesis and reticulin grading. When the chromosome karyotype changed from good to poor, the detected rate of multilineage dyshaematopoiesis, number of lineages with dyshaematopoiesis, positive rate of reticulin and reticulin grading became higher and higher.