TTF-1/p63-positive poorly differentiated NSCLC: A histogenetic hypothesis from the basal reserve cell of the terminal respiratory unit

TTF-1 is expressed in the alveolar epithelium and in the basal cells of distal terminal bronchioles. It is considered the most sensitive and specific marker to define the adenocarcinoma arising from the terminal respiratory unit (TRU). TTF-1, CK7, CK5/6, p63 and p40 are useful for typifying the majority of non-small-cell lung cancers, with TTF and CK7 being typically expressed in adenocarcinomas and the latter three being expressed in squamous cell carcinoma. As tumors with coexpression of both TTF-1 and p63 in the same cells are rare, we describe different cases that coexpress them, suggesting a histogenetic hypothesis of their origin. We report 10 cases of poorly differentiated non-small-cell lung carcinoma (PD-NSCLC). Immunohistochemistry was performed by using TTF-1, p63, p40 (∆Np63), CK5/6 and CK7. EGFR and BRAF gene mutational analysis was performed by using real-time PCR. All the cases showed coexpression of p63 and TTF-1. Six of them showing CK7+ and CK5/6− immunostaining were diagnosed as “TTF-1+ p63+ adenocarcinoma”. The other cases of PD-NSCLC, despite the positivity for CK5/6, were diagnosed as “adenocarcinoma, solid variant”, in keeping with the presence of TTF-1 expression and p40 negativity. A “wild type” genotype of EGFR was evidenced in all cases. TTF1 stained positively the alveolar epithelium and the basal reserve cells of TRU, with the latter also being positive for p63. The coexpression of p63 and TTF-1 could suggest the origin from the basal reserve cells of TRU and represent the capability to differentiate towards different histogenetic lines. More aggressive clinical and morphological features could characterize these “basal-type tumors” like those in the better known “basal-like” cancer of the breast

Immunoistochemical expression of PD-1 and PD-L1 in bone marrow biopsies of patients with acute myeloid leukemia

Background. Haematological and non-haematological malignancies are able to escape the host immune by the capacity to hijack the immune check-points. Several immune check-point molecules are known, such as T cell immunoglobulin mucin-3 (TIM-3), cytotoxic T-cell antigen-4 (CTLA-4), programmed death-1 (PD-1) with its ligand PD-L1 and others.1 The function of these immune check-points is to prevent the damage resulting from an excessive activation of the immune response in the setting of chronic antigenic stimulation, thus leading to autoimmune phenomena, as proved in knock-out mice models. PD-1 is normally present on activated T lymphocytes membrane, acting as a negative costimulatory receptor. PD-L1 is constitutively expressed at low levels by resting lymphocytes, antigen presenting cells and certain immunologically privileged tissues like placenta and testis. PD-L1 expression can be induced as well. In an inflammatory/infective context when T cells recognize antigens expressed by MHC-complex they start to produce inflammatory cytokines. The resulting inflammation leads to the expression of PD-L1 by hematopoietic, epithelial and endothelial cells, activating PD-1 on the surface of T-cells and therefore blocking the immune response. Previous studies have found out that PD-1 is highly expressed on T-reg cells and their binding with PD-L1 enhances suppressor T-reg functions2,3; the activation of PD-1/PD-L1 pathway reduces the lytic capacity of NK cells and B cell antibody production. In solid neoplasms PD-L1 expression by cancer cells and persistent up-regulation of PD-1 by tumourinfiltrating lymphocytes is common45. All these findings brought to the development of check-point inhibitors in the contest of solid tumors and lymphoproliferative neoplasms such as lymphoma and myeloma where the immune checkpoint blockade treatment have shown efficacy in refractory/relapsed neoplasms6. Few investigations only have been conducted on the role of PD1/PD-L1 in myeloid neoplasms, such as acute myeloid leukemia, a haematological cancer characterised by high-risk of relapse and poor prognosis. In leukemia, the bone marrow serves as a sanctuary for neoplastic cells, these cells interact with the tumour microenvironment (TME), constituted by stromal cells, endothelial cells and immune cells. The marked activation of the PD-1/PD-L1 pathway contributes to the maintenance of an immunosuppressive microenvironment. In fact, blasts are able, through the production of immunoinhibitory factors, to suppress the function of immunosurveillance and immuno-elimination of the tumor by the effector T cells. The effector T cells are "exhausted" in their capacity to secrete granzyme B, perforine and interferon gamma, and there is an upregulation of the T-reg functions, in addition to the presence of myeloid-derived suppressor cells7. PD-L1 expression and his link with PD-1 on activated lymphocytes results in an impaired antitumoral activity in murine models8. Zhang et al. investigated the role of PD-1/PD-L1 engagement in murine AML showing that PD-1-/-mice generated augmented antitumoral response in comparison with wild type mice. Similar results were obtained using anti-PD-L1 antibodies.9 A study from Zhou et al. reported how the function of adoptively transferred AML-reactive CTLs was reduced by AML-associated Tregs and how Treg depletion followed by PD-1/PD-L1 blockade showed efficacy for AML eradication in murine models.10 Objective of the study. To assess the presence of PD-1 and PD-L1 positive cells, by immunohistochemistry, in bone marrow biopsies of patients with AML. Material and methods. Four micron thickness sections were obtained from the formalin-fixed paraffin-embedded specimens. Haematoxylin-eosin staining was performed to assess the morphologic features of bone marrow. Immunohistochemical stainings were performed using a Ventana Benchmark Ultra automated staining instrument according to the manufacturer’s recommendations, using anti-PD-1 (clone NAT105, Ventana) and anti-PD-L1 (clone 22C3, Dako) antibodies. Results. We obtained 34 bone marrow trephine biopsies from newly diagnosed AML patients, 17 males and 17 females with a 67.3 mean age. We used 10 healthy bone marrow specimens as normal controls. None out of 10 control bone marrows resulted positive for either PD-1 or PD-L1 expressing cells as expected. Eleven out of 34 AML bone marrows (32,4%) showed at least 1% of PD-L1 positive cells (fig.2 b,d,f), while 6 AML bone marrow samples (17,6%) were positive for at least 1% of PD-1+ cells (fig. 1 b). Discussion. Despite the presence of relevant preclinical data regarding the role of immune check-points, few studies to evaluate the PD1/PDL1 axis have been conducted in myeloid neoplasm. Jia et al. performed flow cytometry analysis on PBMCs and BMMCs of 22 newly diagnosed AML patients and observed a significantly increased frequency of PD-1 expressing CD8 T cells in bone marrow compared to peripheral blood, suggesting a more exhausted status of these cells in relation to the suppressivePaper environment11. Dail et al. measured PD-L1 expression in 7 AML patients using immunohistochemistry and flow cytometry and found that PD-L1 was detectable (>2% cells) in all patients.12 Yang et al. assessed 45 bone marrow biopsies of MDS, CMML and AML patients and found that leukemic blasts of 9 patients (20%) were PD-L1+, while 3 (7%) were positive for PD-1. All 4 controls tested were negative for both PD-1 and PD-L1.13 Daver et al. measured PD-1 expression on bone marrow aspirates of 74 AML patients using flow cytometry. The results showed higher PD-1 expression compared to healthy controls (n=8).14Acceped To our this is the largest study evaluating by immunohistochemistry the expression of PD-1 and PDL1 in AML bone marrows and shows a significative positivity of the activation of the PD-1/PD-L1 pathway which gives a rationale to further studies regarding the charateristics of the cells involved in the PD-1/PD-L1 pathway and the immunosuppressive microenvironment. An implementation of the PD-1/PD-L1 pathway evaluation in clinical setting could have prognostic significance since the expression of PD-L1 by AML blasts has been associated with poor-risk and intermediate-risk AML15, furthermore immune checkpoint inhibitors have shown promising results in maintenance treatment of high-risk AML16, underlining not only a prognostic but also therapeutic value of the PD1/PD-L1 evaluation

Solitary Fibrous Tumor of the Lower Leg: A Rare and Difficult Diagnosis

Solitary fibrous tumor (SFT) is a rare neoplasm that commonly originates in the pleura. Extrapleural locations are rare and for this reason sometimes difficult to diagnose. Malignant forms with local recurrence or distant metastases have been reported, also as a consequence of inappropriate treatment. In this article, we report the case of an SFT of the lower leg in a 37-year-old man. Leg SFT is a rare occurrence, and differential diagnosis may be difficult because they can mimic a variety of benign and malignant mesenchymal tumors; immunohistochemical analysis for CD34, CD99, vimentin, and Bcl-2 is necessary. Misdiagnosis carries a significant risk of inadequate removal with subsequent increased risk of recurrence and distant metastases

Seizure in isolated brain cryptococcoma: Case report and review of the literature

Background: Central nervous system (CNS) cryptococcosis is an invasive fungal infection predominantly seen among immunosuppressed patients causing meningitis or meningoencephalitis. Rarely, cryptococcosis can affect immunologically competent hosts with the formation of localized CNS granulomatous reaction, known as cryptococcoma. Common symptoms of CNS cryptococcoma are headaches, consciousness or mental changes, focal deficits, and cranial nerve dysfunction. Rarely, seizures are the only presenting symptom. Case Description: We report the case of an immunocompetent patient with a solitary CNS cryptococcoma presenting with a long history of non-responsive generalized seizure who has been successfully operated. Conclusion: CNS cryptococcoma is a rare entity, and in immunocompetent patients, its diagnosis can be challenging. The pathophysiology of lesion-related seizure is discussed along with a review of the pertinent literature

Persistence of Nonceliac Wheat Sensitivity, Based on Long-term Follow-up

We investigated how many patients with a diagnosis of nonceliac wheat sensitivity (NCWS) still experienced wheat sensitivity after a median follow-up time of 99 months. We collected data from 200 participants from a previous study of NCWS, performed between July and December 2016 in Italy; 148 of these individuals were still on a strict wheat- free diet. In total, 175 patients (88%) improved (had fewer symptoms) after a diagnosis of NCWS; 145 of 148 patients who adhered strictly to a gluten-free diet (98%) had reduced symptoms, compared with 30 of 52 patients who did not adhere to a gluten-free diet (58%) (P < .0001). Of the 22 patients who repeated the double-blind, placebo- controlled challenge, 20 reacted to wheat. We conclude that NCWS is a persistent condition. Clinicaltrials.gov registration number: NCT02823522

A Case of Fatal Drug Rash Eosinophilia and Systemic Symptoms from Allopurinol

Hypereosinophilia is a systemic condition that has several possible etiologies: allergies, medications, infectious, autoimmune or other systemic diseases, and finally idiopathic forms. Skin involvement seems to relate to subcutaneous inflammatory infiltration in this condition, as can be observed in parasitic, autoimmune and bullous diseases, as well as in drug reactions. Generalizing, a severe adverse drug-induced reaction may cause a systemic inflammatory disease: Drug Rash with Eosinophilia and Systemic Symptoms (DRESS). Its diagnosis requires the application of a complex diagnostic algorithm and immediate identification to prevent inauspicious evolution. The prognosis is severe; drug discontinuation is sometimes not enough and so far the proposed therapies are not always valid. We describe a case of fatal DRESS in which we report: a) difficulties in the management and therapy of the syndrome in its most severe form, and b) need for caution in prescribing drugs potentially inducing DRESS, especially in elderly patients