Cytokeratin expression in hematological neoplasms: a tissue microarray study on 866 lymphoma and leukemia cases

ALK-positive Large B-Cell Lymphoma With Multiple Epithelial Antigen Expression and PABPC1::ALK Fusion: A Novel Molecular Alteration

Anaplastic lymphoma kinase (ALK)-positive large B-cell lymphoma (LBCL) is a very rare type of LBCL with an aggressive clinical course and poor prognosis. This diagnosis can be challenging given the varied morphology (immunoblastic, plasmablastic, or anaplastic), frequent lack of B-cell antigens, and especially in cases with expression of epithelial antigens. Here, we report a case of ALK-positive LBCL with unusual expression of 4 epithelial-associated markers (AE1/AE3, CK8/18, EMA, and GATA3) and novel poly(A) binding protein cytoplasmic 1 (PABPC1)::ALK fusion which has not been previously reported in this entity. This case also emphasizes the use of comprehensive immunophenotyping that includes multiple lineage-specific antibodies when faced with a malignancy without a clear differentiation to avoid misdiagnosis. This case only achieved partial response to combination chemotherapy, radiation, and ALK inhibitor regimens, and furthers our understanding of this uncommon lymphoma.

Cytokeratin and CD56 aberrant co-expression in diffuse large B-cell lymphoma, NOS misinterpreted as metastatic neuroendocrine carcinoma by FNAC

Aberrant expression of epithelial and neuroendocrine markers is rare in diffuse large B-cell lymphoma (DLBCL) and can lead to erroneous diagnosis with inappropriate treatment. This case report describes a case of DLBCL with a co-expression of cytokeratins and CD56 that was misdiagnosed as metastatic neuroendocrine carcinoma.

The Effect of Dietary Intervention With High-Oleocanthal and Oleacein Olive Oil in Patients With Early-Stage Chronic Lymphocytic Leukemia: A Pilot Randomized Trial

Aim

Oleocanthal and oleacein (OC/OL) have important in vitro and in vivo antitumor properties; however, there is no data about their anticancer activity in humans. The aim of this pilot study was to test if patients at early stage of chronic lymphocytic leukemia (CLL) could adhere to and tolerate an intervention with high OC/OL extra virgin olive oil (EVOO) and if this intervention could lead to any changes in markers related to the disease.

Methods

A pilot dietary intervention (DI) was made in patients with CLL in Rai stages 0–II who did not follow any treatment (NCT04215367). In the first intervention (DI1), 20 CLL patients were included in a blind randomized study and were separated into two groups. One group (A) of 10 patients consumed 40 ml/day of high OC/OL-EVOO (416 mg/Kg OC and 284 mg/kg OL) for 3 months. A second group (B) of 10 patients consumed 40 ml/day of low OC/OL (82 mg/kg OC and 33 mg/kg OL) for 3 months. After a washout period of 9–12 months, a second intervention (DI2) only with High OC/OL-EVOO for 6 months was performed with 22 randomly selected patients (16 from the DI1 (8 from each group) and 6 new). Hematological, biochemical, and apoptotic markers were analyzed in the serum of the patients. In addition, cellular proliferation and apoptosis markers were studied in isolated proteins from peripheral blood mononuclear cells.

Results

The results of the DI1 showed beneficial effects on hematological and apoptotic markers only with High OC/OL-EVOO. During the DI2, a decrease in the white blood cell and lymphocyte count was observed (p ≤0.05), comparing 3 months before the intervention and 6 months after it. After 3 and 6 months of DI2, an increase (p ≤0.05) was observed in the apoptotic markers ccK18 and Apo1-Fas, and also in the cell cycle negative regulator p21, and also a decrease in the antiapoptotic protein Survivin, and in the cellular proliferation marker Cyclin D.

Conclusions

This is the first clinical trial with High OC/OL-EVOO that indicates that it could be a promising dietary feature for the improvement of CLL inducing the apoptosis of their cancer cells and improving the metabolism of the patients.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT04215367, identifier: NCT04215367.

The many faces of plasma cell neoplasms: morphological and immunophenotypical variants of the great imitator

Plasma cell neoplasms are notorious for having diverse morphological presentations, and less frequently, unusual immunophenotypical profiles. This unexpected immunomorphological variability could lead to erroneous impressions upon initial assessment, potentially delaying the generation of a final accurate diagnosis. In this review, we present a concise, yet comprehensive summary of both morphological and immunophenotypical variants of plasma cell neoplasms from the archives of MD Anderson Hematopathology Department, with emphasis on possible diagnostic pitfalls precluding a timely and accurate assessment.

NUT Carcinoma: A Clinical, Morphological and Immunohistochemical Mimicker-The Role of RNA Sequencing in the Diagnostic Procedure

Background: NUT carcinoma is a highly aggressive and rare subset of squamous cell carcinoma with grim prognosis. It is under-recognized by both pathologists and oncologists. Recognition is challenging due to its rareness and the fact that its clinical and laboratory features as well as morphological and immunohistochemical characteristics may mimic other malignancies. Case presentation: An interesting case of NUT carcinoma in a 47-year-old male with a large tumor mass in the inferior part of the mediastinum and left lung and increased levels of serum alpha fetoprotein (AFP) is described. Immunohistochemical analysis of both the primary tumor in a bronchoscopy specimen and an excisional biopsy of a subcutaneous metastasis showed positivity for AFP and leukocyte common antigen (LCA) that were misleading and resulted in diagnostic pitfalls of mediastinal germ cell tumor (clinically) and hematolymphoid neoplasm (pathologic report). Immunohistochemical demonstration of NUT protein expression revealed the proper diagnosis, which was further confirmed by RNA sequencing revealing a BRD4-NUTM1 gene fusion.Conclusions: Since NUT carcinoma can show a wide spectrum of histological and immunophenotypic features and can clinically mimic other tumors, use of RNA sequencing with identification of specific NUTM1 fusion partner could be crucial when there are discrepant clinical and histopathological findings. As well, since the category of so-called NUTM1-rearranged neoplasms is rapidly expanding, identification of NUTM1 fusion partner may be essential for the appropriate clinical management.

Cytokeratin expression in plasmablastic lymphoma - a possible diagnostic pitfall in the routine work-up of tumours

AIMS

Plasmablastic lymphoma (PBL) is a rare aggressive B-cell lymphoma that frequently arises at extranodal sites in the setting of immunosuppression. The diagnosis of PBL is complex, owing to a frequent solid or cohesive growth pattern, and an often unusual immunophenotype. Several case reports have described cytokeratin (CK) expression in PBL, introducing a diagnostic pitfall. The aim of this study was to determine the frequency of CK expression in PBL in the largest series available to date.

METHODS AND RESULTS

By using immunohistochemistry in a cohort of 72 PBLs, we identified CK8/18 positivity in 11 of 72 cases (15%) and AE1/3 positivity in six of 65 cases (9%), clearly contrasting with a control series of non-PBL aggressive B-cell lymphomas (one of 96 diffuse large B-cell lymphomas), as well as with data in the literature describing only occasional CK expression in haematological neoplasms.

CONCLUSIONS

Our data indicate CK expression in a substantial number (15%) of PBLs. In view of the particular morphological features of PBL and its frequent negativity for the common leukocyte antigen and B-cell markers, this feature represents a pitfall in the routine diagnostic work-up of PBL, and requires more extensive immunohistochemical and molecular characterisation of cases entering the differential diagnosis.

Aberrant expression of TTF1, p63, and cytokeratins in a diffuse large B-cell lymphoma

Pancytokeratins and TTF-1 are used in working up carcinomas of unknown primary and p63 is expressed in many cell lineages. We present a case of a TTF-1, p63, and cytokeratins positive small round blue cell lesion presenting in a patient with enlarged right supraclavicular lymph nodes and multiple solid pulmonary nodules. The preliminary report to the clinical team was "suspicious for carcinoma." However, after a complete work up the final diagnosis of diffuse large B-cell lymphoma, nongerminal center B-cell phenotype, "double expressor," was rendered (based on Han's algorithm). This case brings up significant diagnostic dilemma as some lymphoid malignancies can morphologically mimic poorly differentiated carcinoma and stain positive for carcinoma markers. Additionally, the frequently used TTF-1 SPT23 antibody clone has strong nuclear staining in rare cases of DLBCL, which is a diagnostic pitfall. To our best knowledge this is the first reported case of DLBCL staining positive for three carcinoma markers.

An Algorithmic Immunohistochemical Approach to Define Tumor Type and Assign Site of Origin

Immunohistochemistry represents an indispensable complement to an epidemiology and morphology-driven approach to tumor diagnosis and site of origin assignment. This review reflects the state of my current practice, based on 15-years' experience in Pathology and a deep-dive into the literature, always striving to be better equipped to answer the age old questions, "What is it, and where is it from?" The tables and figures in this manuscript are the ones I "pull up on the computer" when I am teaching at the microscope and turn to myself when I am (frequently) stuck. This field is so exciting because I firmly believe that, through the application of next-generation immunohistochemistry, we can provide better answers than ever before. Specific topics covered in this review include (1) broad tumor classification and associated screening markers; (2) the role of cancer epidemiology in determining pretest probability; (3) broad-spectrum epithelial markers; (4) noncanonical expression of broad tumor class screening markers; (5) a morphologic pattern-based approach to poorly to undifferentiated malignant neoplasms; (6) a morphologic and immunohistochemical approach to define 4 main carcinoma types; (7) CK7/CK20 coordinate expression; (8) added value of semiquantitative immunohistochemical stain assessment; algorithmic immunohistochemical approaches to (9) "garden variety" adenocarcinomas presenting in the liver, (10) large polygonal cell adenocarcinomas, (11) the distinction of primary surface ovarian epithelial tumors with mucinous features from metastasis, (12) tumors presenting at alternative anatomic sites, (13) squamous cell carcinoma versus urothelial carcinoma, and neuroendocrine neoplasms, including (14) the distinction of pheochromocytoma/paraganglioma from well-differentiated neuroendocrine tumor, site of origin assignment in (15) well-differentiated neuroendocrine tumor and (16) poorly differentiated neuroendocrine carcinoma, and (17) the distinction of well-differentiated neuroendocrine tumor G3 from poorly differentiated neuroendocrine carcinoma; it concludes with (18) a discussion of diagnostic considerations in the broad-spectrum keratin/CD45/S-100-"triple-negative" neoplasm.

Cytologic Evaluation of Tumor-Infiltrating Lymphocytes for Adoptive Cell Therapy

OBJECTIVES

Novel immunotherapeutic options for refractory metastatic cancer patients include adoptive cell therapies such as tumor infiltrating lymphocytes (TILs). This study characterizes the clinicopathologic findings in a cohort of TIL specimens.

METHODS

Patients with metastatic malignancy who were eligible had TILs from their metastases grown and expanded and then sent to pathology.

RESULTS

A total of 11 TIL specimens (10 melanoma, 1 adenocarcinoma) from patients enrolled in an experimental clinical trial were reviewed. All specimens showed more than 200 lymphoid cells, stained positive for lymphoid markers confirming an activated cytotoxic T-cell immunophenotype, and morphologically showed an intermediate-sized population with immature chromatin and frequent mitoses. Six cases (55%) showed large cells with nucleomegaly and prominent nucleoli.

CONCLUSIONS

This report is the first describing cytopathologic findings of autologous TIL therapy including adequacy guidelines and expected cytomorphologic and immunophenotypic findings. To meet this novel clinical demand, a predefined cytology protocol to rapidly process and interpret these specimens needs to be established.

Petrous apex non-secretory plasma cell myeloma with aberrant cytokeratin expression

Multiple myeloma is a monoclonal proliferation of plasma cells with common involvement of vertebrae, ribs and skull vault. However, involvement of skull base is relatively uncommon and myeloma manifesting initially as a petrous apex mass is distinctly rare. We report a rare case of non-secretory multiple myeloma in a 52-year-old Egyptian male presenting primarily as a right petrous apex mass with abducens nerve palsy. Additionally, neoplastic cells aberrantly expressed cytokeratin. Although rare, plasma cell myeloma should be considered in the differential diagnosis of petrous apex masses.

Where do these guests come from? A diagnostic approach for metastatic lymph nodes

Objective

In cases presenting with lymphadenopathies (LAP) without a primary focus detected by simple radiological methods, the primary tumor can be diagnosed by a histopathological evaluation of the metastatic lymph nodes. We aimed to discuss the nonhematological malignancies presenting with lymphadenopathies and the histopathological results for primary tumors.

Material and Methods

In this retrospective study, cases diagnosed with metastasis in excisional lymph nodes between January 2013 and June 2016 were assessed for a histopathological diagnostic approach.

Results

Among 632 lymph node biopsies, a total of 21 cases, involving 12 male and 9 female patients with a mean age of 57.23 y (range, 33-92 y), of nonhematological solid tumors were included. The most common localizations of the involved lymph nodes were inguinal (n=8), axillary (n=6), cervical (n=4), and supraclavicular (n=3) region. The most common primary tumors were malignant melanoma (n=6), breast carcinoma (n=4), ovarian carcinoma (n=2), squamous cell carcinoma (n=2), and germ cell tumor (n=2). Others were papillary thyroid carcinoma, renal cell carcinoma, urothelial carcinoma, prostate adenocarcinoma, and endometrial adenocarcinoma.

Conclusion

Nonhematological malignancies presenting with lymphadenopathies are one of the most complicated cases for clinicians. The histopathological evaluation of the excisional metastatic lymph node biopsies is an important method because of cost effectiveness and easy applicability.

[Space-occupying lesion in the maxillary sinus]

During the preoperative diagnostics of an 80-year-old male patient prior to a planned endarterectomy, an unclear space-occupying lesion was detected in the right nasopharyngeal cavity. It proved to be a dense soft tissue space-occupying lesion of the right maxillary sinus. The histological investigations revealed a partially necrotically decomposed malignant tumor below normal respiratory mucosa free from dysplasia. This case demonstrates the difficulties in differential diagnostics, particularly involving (aberrant) expression of cytokeratin.

Reviewing the current evidence supporting early B-cells as the cellular origin of Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a highly malignant skin cancer characterized by early metastases and poor survival. Although MCC is a rare malignancy, its incidence is rapidly increasing in the U.S. and Europe. The discovery of the Merkel cell polyomavirus (MCPyV) has enormously impacted our understanding of its etiopathogenesis and biology. MCCs are characterized by trilinear differentiation, comprising the expression of neuroendocrine, epithelial and B-lymphoid lineage markers. To date, it is generally accepted that the initial assumption of MCC originating from Merkel cells (MCs) is unlikely. This is owed to their post-mitotic character, absence of MCPyV in MCs and discrepant protein expression pattern in comparison to MCC. Evidence from mouse models suggests that epidermal/dermal stem cells might be of cellular origin in MCC. The recently formulated hypothesis of MCC originating from early B-cells is based on morphology, the consistent expression of early B-cell lineage markers and the finding of clonal immunoglobulin chain rearrangement in MCC cells. In this review we elaborate on the cellular ancestry of MCC, the identification of which could pave the way for novel and more effective therapeutic regimens.

Undifferentiated Nasopharyngeal Carcinoma Mimicking Hodgkin Lymphoma With CD30 Expression

The presence of CD30-expressing Hodgkin-like cells with a background of inflammation and eosinophils in a young adolescent is usually diagnostic of classical Hodgkin lymphoma. Herein we present the case of a 12-year-old boy presenting with enlarged cervical lymph node characterized by the presence of Hodgkin-like cells expressing CD30 and EBV-LMP1 with a Hodgkin-like background. The Hodgkin-like cells were negative for CD15, CD20, CD45, and Pax-5. The tumor cells, however, expressed several cytokeratins, confirming the diagnosis of an undifferentiated carcinoma nasopharyngeal type. This case highlights the importance of possessing a high index of suspicion when encountering lymph nodes with Hodgkin-like cells and a Hodgkin-like background, even with CD30 expression, as the differential can include undifferentiated carcinoma nasopharyngeal type.

Oct2 and Bob1 are sensitive and specific markers in lineage determination of B cell lymphomas with no expression of conventional B cell markers

AIMS

Rare cases of B cell lymphomas do not express conventional B cell markers (CD20, CD79a and PAX5), and these types of lymphomas include anaplastic lymphoma kinase (ALK)-positive large B cell lymphoma, plasmablastic lymphoma, primary effusion lymphoma and the solid variant of primary effusion lymphoma, extracavitary human herpesvirus 8 (HHV8)-positive large B cell lymphoma. Establishing accurate diagnoses of these B cell lymphomas can be challenging, and often requires a large panel of immunohistochemical stains, molecular assays and cytogenetic studies. B cell-specific transcription factors, Oct2 and Bob1, have been shown to be expressed consistently in most, if not all, B cell lymphomas, and therefore we investigated the utility of Oct2 and Bob1 immunohistochemistry in lineage determination of the aforementioned B cell lymphomas.

METHODS AND RESULTS

We selected 34 cases of previously diagnosed B cell lymphomas with no or weak expression of CD20, CD79a and PAX5. Oct2 and Bob1 were positive in 74% (25 of 34) and 85% (29 of 34) of the cases, respectively. When we combined the results of these two immunostains, 94% (32 of 34) cases expressed at least one of these two markers. We also included 51 control cases of non-B cell neoplasms, and none of them expressed either Oct2 or Bob1.

CONCLUSIONS

Oct2 and Bob1 are very reliable in determining B cell lineage in the absence of expression of other pan-B cell markers, and it should provide great diagnostic benefit to include them both in a panel of immunohistochemistry to assess undifferentiated malignant neoplasms.

Recent Advances in Aggressive Large B-cell Lymphomas: A Comprehensive Review

Diffuse large B-cell lymphoma (DLBCL) is an aggressive disease with considerable heterogeneity reflected in the 2008 World Health Organization classification. In recent years, genome-wide assessment of genetic and epigenetic alterations has shed light upon distinct molecular subsets linked to dysregulation of specific genes or pathways. Besides fostering our knowledge regarding the molecular complexity of DLBCL types, these studies have unraveled previously unappreciated genetic lesions, which may be exploited for prognostic and therapeutic purposes. Following the last World Health Organization classification, we have witnessed the emergence of new variants of specific DLBCL entities, such as CD30 DLBCL, human immunodeficiency virus-related and age-related variants of plasmablastic lymphoma, and EBV DLBCL arising in young patients. In this review, we will present an update on the clinical, pathologic, and molecular features of DLBCL incorporating recently gained information with respect to their pathobiology and prognosis. We will emphasize the distinctive features of newly described or emerging variants and highlight advances in our understanding of entities presenting a diagnostic challenge, such as T-cell/histiocyte-rich large B-cell lmphoma and unclassifiable large B-cell lymphomas. Furthermore, we will discuss recent advances in the genomic characterization of DLBCL, as they may relate to prognostication and tailored therapeutic intervention. The information presented in this review derives from English language publications appearing in PubMed throughout December 2015. For a complete outline of this paper, please visit: http://links.lww.com/PAP/A12.

Merkel cell carcinoma: is this a true carcinoma?

Recent years have brought an enhanced understanding of Merkel cell carcinoma (MCC) biology, especially with regard to the Merkel cell polyoma virus as a causative agent. Differences between Merkel cell polyomavirus-positive and Merkel cell polyomavirus-negative MCC in morphology; gene expression, miRNA profiles and prognosis have been reported. Origin of MCC is controversial. Presence of neurosecretory granules has suggested that these carcinomas originate from one of the neurocrest derivatives, most probably Merkel cells; the name Merkel cell carcinoma is now widely accepted. Expression of PGP 9.5, chromogranin A and several neuropeptides, initially regarded as specific markers for neural and neuroendocrine cells, has recently been shown in a subset of lymphomas. MCC commonly expresses terminal deoxynucleotidyl transferase and PAX5. Their co-expression under physiologic circumstances is restricted to pro/pre-B cells and pre-B cells. These findings lead to the hypothesis by zur Hausen et al. that MCC originates from early B cells. This review was intended to critically appraise zur Hausen's hypothesis and discuss the possibility that MCC is a heterogenous entity with distinct subtypes.

Skeletal Metastasis

The most commonly diagnosed tumor in the skeleton represents metastatic disease. Metastatic carcinoma should be the first consideration in older patients with atypical radiologic findings or clinical features suggestive of a bone lesion. The primary goal in the setting of skeletal metastasis is usually palliation.

Significance of circulating tumor cells in patients with squamous cell carcinoma of the head and neck: initial results

OBJECTIVES

to present and discuss a high-performance negative depletion method for the isolation of circulating tumor cells (CTCs) in the blood of patients with head and neck cancer and to determine the correlation between the presence of CTCs and early clinical outcome in these patients.

DESIGN

prospective clinical follow-up study of patients with squamous cell carcinoma of the head and neck (SCCHN) undergoing surgical intervention, who had peripheral blood examined for the presence of CTCs.

PATIENTS

the study population comprised 48 patients diagnosed as having SCCHN and undergoing surgical intervention.

INTERVENTION

a negative depletion process to isolate and quantify CTCs from the blood of patients with SCCHN using immunomagnetic separation was developed and validated. Immunostaining for cytokeratin was performed on the enriched samples to determine the number of CTCs extracted from each patient's blood sample. Correlation of the presence of CTCs, tumor stage, nodal status, clinical characteristics, and outcome was made.

MAIN OUTCOME MEASURE

disease-free survival.

RESULTS

our initial data, that have a mean follow-up of 19.0 months, suggest that patients with no detectable CTCs per milliliter of blood had a significantly higher probability of disease-free survival (P = .01). There was no correlation between the presence of CTCs with regard to age, sex, tumor site, stage, or nodal involvement.

CONCLUSIONS

our enrichment technology, based on the removal of normal cells, has been used on the peripheral blood of patients with head and neck cancer for which follow-up data were collected. If no CTCs were present, a statistically significant improved disease-free survival was observed in SCCHN. A blood test with such a prognostic capability could have important implications in the treatment of patients with head and neck cancer.

Unknown primary tumors

An unknown primary tumor (UPT) is defined by the presence of a metastatic cancer without a known primary site of origin despite a standardized diagnostic workup. Clinically, UPTs show rapid progression and early dissemination, with signs and symptoms related to the metastatic site. The molecular bases of their biology remain largely unknown, with no evidence as to whether they represent a distinct biological entity. Immunohistochemistry remain the best diagnostic tool in term of cost-effectiveness, but the time-consuming "algorithmic process" it relies on has led to the application of new molecular techniques for the identification of the primary site of UPTs. For example, several microarray or miRNA classifications of UPTs have been used, with an accuracy in the prediction of the primary site as high as 90%. It should be noted that validating a prediction of tissue origin is challenging in these patients, since most of them will never have a primary site identified. Moreover, prospective studies to determine whether selection of treatment options based on such profiling methods actually improves patient outcome are still missing. In the last few years functional imaging (i.e. FDG-PET/CT) has gained a main role in the detection of the site of origin of UPTs and is currently recommended by the European Association of Nuclear Medicine. However, despite recent refinements in the diagnostic workup, the site of origin of UPT often remains elusive. As a consequence, treatment of patients with UPT is still empirical and inadequate.

Specific detection of CD56 (NCAM) isoforms for the identification of aggressive malignant neoplasms with progressive development

Alternative splicing of transcripts from many cancer-associated genes is believed to play a major role in carcinogenesis as well as in tumor progression. Alternative splicing of one such gene, the neural cell adhesion molecule CD56 (NCAM), impacts the progression, inadequate therapeutic response, and reduced total survival of patients who suffer from numerous malignant neoplasms. Although previous investigations have determined that CD56 exists in three major isoforms (CD56(120kD), CD56(140kD), and CD56(180kD)) with individual structural and functional properties, neither the expression profiles nor the functional relevance of these isoforms in malignant tumors have been consistently investigated. Using new quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) strategies and novel CD56 isoform-specific antibodies, CD56(140kD) was shown to be exclusively expressed in a number of highly malignant CD56(+) neoplasms and was associated with the progression of CD56(+) precursor lesions of unclear malignant potential. Moreover, only CD56(140kD) induced antiapoptotic/proliferative pathways and specifically phosphorylated calcium-dependent kinases that are relevant for tumorigenesis. We conclude, therefore, that the specific detection of CD56 isoforms will help to elucidate their individual functions in the pathogenesis and progression of malignant neoplasms and may have a positive impact on the development of CD56-based immunotherapeutic strategies.