Lymphoplasmacytic lymphoma/Waldenström macroglobulinemia: one disease or three?

Serous fluids and hematolymphoid disorders

Diagnosing hematolymphoid neoplasm by evaluating fine-needle aspiration (FNA) cytology sample is controversial and requires experience and clinical skills. This concept becomes more challenging when evaluating hematolymphoid neoplasm in body fluid. Differentiating between low-grade lymphoma and reactive lymphocytes is often difficult by morphology alone as reactive lymphoid cells may acquire activation morphology from being exposed to different cytokines within the body fluid. However, in most cases there are specific features that may aid in differentiating small reactive from non-reactive lymphocytes including the round shape of the nucleus, the absence of visible nucleoli and the presence of fine clumped chromatin. In large cell lymphoma and leukemia cells involvement of body fluid this concept becomes less challenging. Large cell lymphoma and leukemia cells tend to have large size nuclei, less mature chromatin, and visible nucleoli with and without cytoplasmic vacuoles. However, to reach accurate diagnosis and subclassification, the utilizing of flow cytometry, to confirm monoclonality, and other ancillary studies such immunocytochemistry, cytogenetics and molecular studies is needed. This review article will be incorporated finally as one of the chapters in CMAS (CytoJournal Monograph/Atlas Series) #2. It is modified slightly from the chapter by the initial authors in the first edition of Diagnostic Cytopathology of Serous Fluids.

Clinical significance of intrapulmonary lymph node dissection in pathological stage IA non-small cell lung cancer: A propensity score matching analysis

Background

This study aimed to investigate the prognostic impact of intrapulmonary lymph node (ILN, stations 13–14) dissection on disease‐free survival (DFS) in stage IA non‐small cell lung cancer (NSCLC) patients in order to facilitate a more suitable determination of surgical strategies for early‐stage cases.

Methods

We retrospectively analyzed 416 patients with pathological stage IA NSCLC from February 2016 to November 2019. The patients were divided into a group with ILN dissection (ILN^D+ group) and a group without ILN dissection (ILN^D‐ group). DFS was compared using the Kaplan–Meier method and compared statistically using the log‐rank test before and after propensity score matching (PSM). Subgroup analysis of DFS stratified based on tumor size was also calculated.

Results

Both before and after PSM, the four‐year DFS of the ILN^D+ group was greatly increased compared to that of ILN^D‐ group (90.1% vs. 79.7%, p = 0.003; 95.5% vs. 80.6%, p = 0.003, respectively) and multivariable cox regression analysis revealed ILN dissection was an independent factor favoring DFS in stage IA NSCLC (p = 0.016 and p = 0.015, respectively). Subgroup analysis revealed the four‐year DFS was comparable between the ILN ^D+ and ILN^D‐ groups with regard to tumor size ≤1.5 cm (90.6% vs. 92.7%, p = 0.715). However, the ILN ^D+ group was found to have a better oncological outcome compared with the ILN^D‐ group with regard to tumor size >1.5 cm (90.0% vs. 73.8%, p = 0.003).

Conclusions

The prognostic impact of ILN dissection on patients with stage IA NSCLC appears to be significantly influenced by tumor size, and this should be taken into account when choosing the most appropriate therapeutic modality.

Positive Lymph Node Counts in American Thyroid Association Low-Risk Papillary Thyroid Carcinoma Patients

BACKGROUND

Current American Thyroid Association (ATA) guidelines state that patients with intermediate-risk papillary thyroid cancer (PTC) may benefit from remnant ablation. One criterion for intermediate-risk classification is >5 positive lymph nodes (LNs). We investigate whether performing step-sectioning of LNs increases the metastatic detection rate, thereby influencing ATA risk of recurrence (ROR) classification.

METHODS

A retrospective review was conducted of cases in which ≥ 5 LNs were removed during thyroidectomy and ≤5 LNs were found positive for PTC. Step-sectioning was performed on the original tissue blocks. All slides were re-reviewed by a senior pathologist.

RESULTS

Twenty patients met study criteria. Step-sectioning significantly increased LN yield compared to standard sectioning. In total, we found 12 new positive lymph nodes; seven (58%) were in totally new lymph nodes, while five (42%) were in lymph nodes previously read as negative. All newly discovered metastases were classified as micrometastases (≤2 mm). Of the 15 patients originally classified as low-risk, the step-sectioning protocol impacted two patients (13%), increasing ROR stratification.

CONCLUSION

Intensive step-sectioning reveals additional micrometastases. More detailed analysis did not identify clinically significant nodal disease likely to impact the clinical course of patients in this study. Our study supports current standards of pathology specimen handling related to LN assessment and the impact on ATA ROR classification. Nonetheless, it is important for clinicians to understand their institution's sectioning protocol utilized to report positive and total LN counts, which could impact ATA risk stratification and denote the comprehensive nature of the LN dissection that was performed.

A prediction model for lymph node metastases using pathologic features in patients intraoperatively diagnosed as stage I non-small cell lung cancer

Background

There is little information on which pattern should be chosen to perform lymph node dissection for stage I non-small-cell lung cancer. This study aimed to develop a model for predicting lymph node metastasis using pathologic features of patients intraoperatively diagnosed as stage I non-small-cell lung cancer.

Methods

We collected pathology data from 284 patients intraoperatively diagnosed as stage I non-small-cell lung cancer who underwent lobectomy with complete lymph node dissection from 2013 through 2014, assessing various factors for an association with metastasis to lymph nodes (age, gender, pathology, tumour location, tumour differentiation, tumour size, pleural invasion, bronchus invasion, multicentric invasion and angiolymphatic invasion). After analysing these variables, we developed a multivariable logistic model to estimate risk of metastasis to lymph nodes.

Results

Univariate logistic regression identified tumour size >2.65 cm (p < 0.001), tumour differentiation (p < 0.001), pleural invasion (p = 0.034) and bronchus invasion (p < 0.001) to be risk factors significantly associated with the presence of metastatic lymph nodes. On multivariable analysis, only tumour size >2.65 cm (p < 0.001), tumour differentiation (p = 0.006) and bronchus invasion (p = 0.017) were independent predictors for lymph node metastasis. We developed a model based on these three pathologic factors that determined that the risk of metastasis ranged from 3% to 44% for patients intraoperatively diagnosed as stage I non-small-cell lung cancer. By applying the model, we found that the values ŷ > 0.80, 0.43 < ŷ ≤ 0.80, ŷ ≤ 0.43 plus tumour size >2 cm and ŷ ≤0.43 plus tumour size ≤2 cm yielded positive lymph node metastasis predictive values of 44%, 18%, 14% and 0%, respectively.

Conclusions

A non-invasive prediction model including tumour size, tumour differentiation and bronchus invasion may be useful to give thoracic surgeons recommendations on lymph node dissection for patients intraoperatively diagnosed as Stage I non-small cell lung cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3273-x) contains supplementary material, which is available to authorized users.

Missed Intrapulmonary Lymph Node Metastasis and Survival After Resection of Non-Small Cell Lung Cancer

BACKGROUND

Pathologic nodal stage is a key prognostic factor for patients with surgically resected lung cancer. We previously described the extent of missed intrapulmonary nodal metastasis in a cohort of patients treated at institutions in metropolitan Memphis, TN. With long-term follow-up, we now quantify the survival impact of missed nodal metastasis.

METHODS

We conducted a prospective cohort study to evaluate inadvertently discarded lymph nodes in re-dissected remnant lung resection specimens from lung cancer patients. Retrieved material was histologically examined and classified as lymph nodes with and without metastasis. Survival information was obtained from hospital cancer registries. We plotted survival distributions with the use of the Kaplan-Meier method and evaluated them with proportional hazards models that controlled for important demographic and clinical factors.

RESULTS

The study included 110 patients who were 54% women and 69% white. Discarded lymph nodes with metastasis were found in 25 patients (23%). Patients with missed lymph node metastasis had an increased risk of death with an unadjusted hazard ratio of 2.0 (p = 0.06) and an adjusted hazard ratio of 1.4 (p = 0.45) compared with patients without missed lymph node metastasis. Patients with more than 2 missed lymph nodes with metastasis had 4.8 times the hazard of death (p = 0.0005) compared with patients without missed lymph node metastasis (adjusted hazard ratio 6.5, p = 0.0001).

CONCLUSIONS

Metastasis to inadvertently discarded intrapulmonary lymph nodes from lung cancer resection specimens was associated with reduced survival. A more rigorous gross dissection protocol for lung cancer resection specimens may provide prognostically useful information.

Improving the pathologic evaluation of lung cancer resection specimens

Accurate post-operative prognostication and management heavily depend on pathologic nodal stage. Patients with nodal metastasis benefit from post-operative adjuvant chemotherapy, those with mediastinal nodal involvement may also benefit from adjuvant radiation therapy. However, the quality of pathologic nodal staging varies significantly, with major survival implications in large populations of patients. We describe the quality gap in pathologic nodal staging, and provide evidence of its potential reversibility by targeted corrective interventions. One intervention, designed to improve the surgical lymphadenectomy, specimen labeling, and secure transfer between the operating theatre and the pathology laboratory, involves use of pre-labeled specimen collection kits. Another intervention involves application of an improved method of gross dissection of lung resection specimens, to reduce the inadvertent loss of intrapulmonary lymph nodes to histologic examination for metastasis. These corrective interventions are the subject of a regional dissemination and implementation project in diverse healthcare systems in a tri-state region of the United States with some of the highest lung cancer incidence and mortality rates. We discuss the potential of these interventions to significantly improve the accuracy of pathologic nodal staging, risk stratification, and the quality of specimens available for development of stage-independent prognostic markers in lung cancer.

Size and histologic characteristics of lymph node material retrieved from tissue discarded after routine pathologic examination of lung cancer resection specimens

Redissection of discarded lung resection specimens after routine pathology examination reveals missed lymph node metastasis. We sought to determine if size can be used to grossly select lymph nodes for microscopic examination. This is a prospective cohort study of lymph nodes retrieved from discarded lung resection specimens. The association between size and histologic characteristics of retrieved material was compared by the Wilcoxon-Mann-Whitney test. We retrieved 1094 grossly 'lymph node-like" tissue from 112 remnant lung resection specimens, of which 345 (32%) proved not to be lymph nodes and 71 (9%) of 749 lymph nodes had metastasis. Metastasis was present in discarded nodes in 26 (23%) of 112 patients. The non-lymph node tissue was significantly smaller than lymph nodes (P < .0001); lymph nodes with metastases were significantly larger than those without metastases (P < .0001). However, there was significant size overlap between the 3 types of grossly lymph node-like tissue. Thirty-two percent of nodes with metastasis were less than 1 cm; 15% of patients had at least 1 lymph node less than 1 cm with metastasis. The size difference between lymph nodes with and without metastasis is clinically unhelpful because of broad overlap. Size is insufficiently discriminatory and cannot be relied on to select materials for histologic examination. A third of grossly retrieved material was non-lymph node tissue. This probably occurs during routine pathologic examination and likely contributes to the low N1 lymph node count.

Towards optimal pathologic staging of resectable non-small cell lung cancer

Pathologic nodal staging is the most accurate means of determining prognosis of patients with resectable non-small cell lung cancer (NSCLC), but confusion prevails about the optimal pre-operative and surgical lymph node examination procedures for candidates of curative-intent resection. The landmark American College of Surgeons Oncology Group Z0030 trial revealed no difference in the survival of patients with clinical T1 or T2, N0 or N1 (hilar node-negative), M0 NSCLC who either had a fastidious, pre-defined systematic hilar and mediastinal lymph node sampling procedure, or who received a complete mediastinal lymph node dissection. We place the results of this major trial into a contemporary clinical practice context, and discuss problems associated with apparent misunderstanding of the lessons from this trial, especially in light of evidence of prevailing sub-optimal nodal examination practices. We also discuss evolving knowledge about the origin of the quality gap in pathologic nodal staging and the emerging literature on corrective interventions.

Clinical and surgical-pathological staging in early non-small cell lung cancer

Staging is of the utmost importance in the evaluation of a patient with non-small cell lung cancer (NSCLC) because it defines the actual extent of the disease. Accurate staging allows multidisciplinary oncology teams to plan the best surgical or medical treatment and to predict patient prognosis. Based on the recommendation of the International Association for the Study of Lung Cancer (IASLC), a tumor, node, and metastases (TNM) staging system is currently used for NSCLC. Clinical staging (c-TNM) is achieved via non-invasive modalities such as examination of case history, clinical assessment and radiological tests. Pathological staging (p-TNM) is based on histological examination of tissue specimens obtained with the aid of invasive techniques, either non-surgical or during the intervention. This review is a critical evaluation of the roles of current pre-operative staging modalities, both invasive and non-invasive. In particular, it focuses on new techniques and their role in providing accurate confirmation of patient TNM status. It also evaluates the surgical-pathological staging modalities used to obtain the true-pathological staging for NSCLC.

Pathogenesis of human B cell lymphomas

The mechanisms that drive normal B cell differentiation and activation are frequently subverted by B cell lymphomas for their unlimited growth and survival. B cells are particularly prone to malignant transformation because the machinery used for antibody diversification can cause chromosomal translocations and oncogenic mutations. The advent of functional and structural genomics has greatly accelerated our understanding of oncogenic mechanisms in lymphomagenesis. The signaling pathways that normal B cells utilize to sense antigens are frequently derailed in B cell malignancies, leading to constitutive activation of prosurvival pathways. These malignancies co-opt transcriptional regulatory systems that characterize their normal B cell counterparts and frequently alter epigenetic regulators of chromatin structure and gene expression. These mechanistic insights are ushering in an era of targeted therapies for these cancers based on the principles of pathogenesis.

Isolated tumour cells in pathological node-negative lymph nodes adversely affect prognosis in cancer of the oesophagus or oesophagogastric junction

AIMS

To determine the prevalence of isolated tumour cells (ITC) in lymph nodes of patients with pathological node-negative (pN0) tumours and to assess their impact on disease-free and overall survival.

METHODS

Paraffin embedded lymph nodes from oesophagogastrectomy specimens were examined immunohistochemically using monoclonal anti-cytokeratin antibody (MNF118). Clinical and pathological features were summarised and overall and relapse-free survival were estimated.

RESULTS

Isolated tumour cells were detected in 12 of 146 patients (8%), and 24 of 1694 (1%) lymph nodes. With a median follow-up time of 28 months (range 0-160 months), both relapse-free and overall survival were significantly (p<0.05) associated with the presence of ITC in pN0 lymph nodes. There was no significant difference in the prevalence of ITC between patients who underwent multimodal therapy and those treated with surgery alone.

CONCLUSIONS

ITC in pN0 lymph nodes may be less frequent than previously considered, but their presence is associated with poorer outcomes compared with true node negative disease.

Low-grade B-Cell lymphomas with plasmacytic differentiation lack PAX5 gene rearrangements

The chromosomal translocation t(9;14)(p13;q32) has been reported in association with lymphoplasmacytic lymphoma (LPL). Although this translocation involving the paired homeobox-5 (PAX5) gene at chromosome band 9p13 and the immunoglobulin heavy chain (IgH) gene at 14q32 has been described in approximately 50% of LPL cases, the actual number of cases studied is quite small. Many of the initial cases associated with t(9;14)(p13;q32) were actually low-grade B-cell lymphomas with plasmacytic differentiation other than LPL. Thus, we analyzed a series of low-grade B-cell lymphomas for PAX5 gene rearrangements. We searched records from the Department of Pathology, Stanford University Medical Center for low-grade B-cell lymphomas, with an emphasis on plasmacytic differentiation, that had available paraffin blocks or frozen tissue. We identified 37 cases, including 13 LPL, 18 marginal zone lymphomas (nodal, extranodal, splenic, and alpha-heavy chain disease), and 6 small lymphocytic lymphomas. A novel dual-color break-apart bacterial artificial chromosome probe was designed to flank the PAX5 gene, spanning previously described PAX5 breakpoints, and samples were analyzed by interphase fluorescence in situ hybridization. All cases failed to demonstrate a PAX5 translocation, indicating that t(9;14)(p13;q32) and other PAX5 translocations are uncommon events in low-grade B-cell lymphomas with plasmacytic differentiation. This study also confirms recent reports that found an absence of PAX5 rearrangements in LPL, suggesting the reassessment of PAX5 rearrangements in LPL.

Lymphomatoid papulosis in a patient with Waldenström's macroglobulinemia

Lymphomatoid papulosis (LyP) is a rare skin disease with a benign course but a malignant histologic appearance based on atypical lymphocytes. Waldenström's macroglobulinemia (WM) is a diffuse infiltration of the bone marrow by cells that synthesize IgM immunoglobulins. A 46-year-old female presented with a two year history of weakness, fatigue, anemia, and recurring multiple erythematous papules and nodules in the skin. The skin biopsy showed pleomorphic lymphoid cells with atypical mitoses permeated by a diffuse dermal infiltrate of normal appearing lymphocytes. The neoplastic cells were positive for CD30, CD3, and CD5 but negative for CD20 and EMA. The bone marrow was hypercellular due to a diffuse infiltration by lymphocytes, plasma cells, and plasmacytoid lymphocytes. LyP is a lymphoproliferative disorder of CD30-positive T cells that may be associated with other lymphoid malignancies, particularly Hodgkin's disease, mycosis fungoides, and anaplastic T cell lymphomas. To our knowledge, this is the first report of a LyP appearing in a patient with WM.

Lack of PAX5 rearrangements in lymphoplasmacytic lymphomas: reassessing the reported association with t(9;14)1 1These studies were performed in the University of Pittsburgh Cancer Institute Cytogenetics Facility

A t(9;14)(p13;q32) involving the PAX5 and IGH genes has been described in association with lymphoplasmacytic lymphoma. Although often described as common, the incidence of this translocation in nodal lymphoplasmacytic lymphoma has never been investigated. Recent studies of patients with Waldenström's macroglobulinemia (often corresponding to marrow-based lymphoplasmacytic lymphoma) have failed to identify the t(9;14). These studies have suggested that either nodal and marrow-based lymphoplasmacytic lymphomas have distinct pathogenetic mechanisms or that the t(9;14) is less frequent in lymphoplasmacytic lymphoma than was believed previously. We therefore analyzed a series of nodal or other extramedullary lymphoplasmacytic lymphomas for the presence of the t(9;14) with paraffin section interphase fluorescence in situ hybridization. We developed a BAC contig probe spanning all previously described PAX5 breakpoints and validated this assay with the KIS-1 cell line that expresses a t(9;14). Analysis with the PAX5 probe showed a lack of PAX5 rearrangements in all cases that were analyzed successfully. Similarly, analysis by an IGH fluorescence in situ hybridization probe showed no evidence of translocations involving the IGH locus. These findings indicate that the t(9;14) is at least uncommon in lymphoplasmacytic lymphoma and should no longer be considered a characteristic finding in this type of lymphoma as defined by World Health Organization criteria.

Developing diagnostic criteria in Waldenstrom's macroglobulinemia

Waldenstrom's macroglobulinemia (WM) is a poorly characterized B-cell lymphoproliferative disorder. There are a relatively limited number of detailed clinicopathological assessments, while the majority of clinical trials have been nonrandomized, single-institution phase II studies. Unfortunately progress in this disorder has been hindered by a lack of universally accepted diagnostic criteria. It is clear that criteria incorporating clinical, morphological, immunophenotypic, and, ultimately, genotypic parameters are needed for future clinical trails. Following a detailed clinicopathological assessment of 111 patients and a review of the published literature the following diagnostic criteria were proposed for WM: IgM monoclonal gammopathy of any concentration, bone marrow infiltration by small lymphocytes, plasmacytoid cells and plasma cells in a diffuse, interstitial or nodular pattern, and a surface Ig(+)CD19(+)CD20(+)CD5(-)CD10(-)CD23(-) immunophenotype.

Differential diagnosis of Waldenstrom's macroglobulinemia from other low-grade B-cell lymphoproliferative disorders

Waldenstrom's macroglobulinemia (WM) is a rare lymphoproliferative disorder (LPD) characterized by lymphoplasmacytic infiltration of the bone marrow (BM) and/or occasionally other tissues and by the presence of a serum monoclonal IgM. The disease belongs to the lymphoplasmacytic lymphoma (LPL) subtype. Whether WM is indeed a separate entity or is merely an IgM-secreting subtype of low-grade B-cell lymphoma is still controversial. In our series of 67 patients, WM has a long median overall survival of 110 months, and the male/female ratio is 1.2/1. Clinical features include a wide spectrum of manifestations, many of which may be common to other LPDs. Differential diagnosis is based on: (1) clinical and laboratory features (anemia, organomegaly, lymphadenopathy, IgM paraproteinemia), (2) cell morphology (lymphocytes, lymphoplasmacytes, few plasma cells), (3) histopathology of bone marrow or lymph node, (4) immunophenotype (CD5 expression and the intensity of CD5, CD20, and CD79b antigens may help in discrimination from other LPDs and atypical CLL), and (5) characteristic genetic features (present in other LPDs). Based on the former, diagnosis is usually easy. It may be harder in LPL cases not secreting IgM. We consider that WM should be, for the time being, handled as a separate entity. Further studies are necessary.

Splenic marginal-zone lymphoma: a distinct clinical and pathological entity

In the World Health Organization classification system, splenic marginal-zone lymphoma (splenic MZL) is described as an indolent B-cell lymphoma, which generally presents as splenomegaly with involvement of the bone marrow and peripheral blood. Presence of disease in peripheral lymph nodes and extranodal locations is uncommon. Splenic MZL is characterised by micronodular infiltration of the spleen with marginal-zone differentiation; the immunophenotype is usually IgM+ IgD+/- cytoplasmic-Ig-/+ pan B antigens+ CD5- CD10- CD23- CD43-/+ cyclin D1-; and the most common genetic abnormalities are deletions at 7q22-7q32. Most patients with splenic MZL live for a long time but classic prognostic factors cannot distinguish between patients who are likely to have good and poor outcomes. However, immunological events, such as haemolytic anaemia and immune thrombocytopenia, or the presence of a monoclonal component, are significantly associated with shorter survival. Splenectomy is considered the first-line treatment of choice for splenic MZL; it results in only partial remission, but responses are generally sufficient for correcting cytopenia, improving quality of life, and increasing survival.