Morphologic Features of Invasion in Lung Adenocarcinoma: Diagnostic Pitfalls.

Reproducibility of pulmonary invasive adenocarcinoma diagnosis is poor when applying the World Health Organization (WHO) classification. In this article, we aimed first to explain by 3-dimensional morphology why simple pattern recognition induces pitfalls for the assessment of invasion as applied in the current WHO classification of pulmonary adenocarcinomas. The underlying iatrogenic-induced morphologic alterations in collapsed adenocarcinoma in situ overlap with criteria for invasive adenocarcinoma. Pitfalls in seemingly acinar and papillary carcinoma are addressed with additional cytokeratin 7 and elastin stains. In addition, we provide more stringent criteria for a better reproducible and likely generalizable classification.

Elastin in pulmonary pathology: relevance in tumours with a lepidic or papillary appearance. A comprehensive understanding from a morphological viewpoint.

Elastin and collagen are the main components of the lung connective tissue network, and together provide the lung with elasticity and tensile strength. In pulmonary pathology, elastin staining is used to variable extents in different countries. These uses include evaluation of the pleura in staging, and the distinction of invasion from collapse of alveoli after surgery (iatrogenic collapse). In the latter, elastin staining is used to highlight distorted but pre-existing alveolar architecture from true invasion. In addition to variable levels of use and experience, the interpretation of elastin staining in some adenocarcinomas leads to interpretative differences between collapsed lepidic patterns and true papillary patterns. This review aims to summarise the existing data on the use of elastin staining in pulmonary pathology, on the basis of literature data and morphological characteristics. The effect of iatrogenic collapse and the interpretation of elastin staining in pulmonary adenocarcinomas is discussed in detail, especially for the distinction between lepidic patterns and papillary carcinoma.

Interobserver variation in the classification of thymic lesions including biopsies and resection specimens in an international digital microscopy panel.

AIMS: Thymic tumours are rare in routine pathology practice. Although the World Health Organization (WHO) classification describes a number of well-defined categories, the classification remains challenging. The aim of this study was to investigate the reproducibility of the WHO classification among a large group of international pathologists with expertise in thymic pathology and by using whole slide imaging to facilitate rapid diagnostic turnover. METHODS AND RESULTS: Three hundred and five tumours, consisting of 90 biopsies and 215 resection specimens, were reviewed with a panel-based virtual microscopy approach by a group of 13 pathologists with expertise in thymic tumours over a period of 6 years. The specimens were classified according to the WHO 2015 classification. The data were subjected to statistical analysis, and interobserver concordance (Fleiss kappa) was calculated. All cases were diagnosed within a time frame of 2 weeks. The overall level of agreement was substantial (κ = 0.6762), and differed slightly between resection specimens (κ = 0.7281) and biopsies (κ = 0.5955). When analysis was limited to thymomas only, and they were grouped according to the European Society for Medical Oncology Clinical Practice Guidelines into B2, B3 versus A, AB, B1 and B3 versus A, AB, B1, B2, the level of agreement decreased slightly (κ = 0.5506 and κ = 0.4929, respectively). Difficulties arose in distinguishing thymoma from thymic carcinoma. Within the thymoma subgroup, difficulties in distinction were seen within the B group. CONCLUSIONS: Agreement in diagnosing thymic lesions is substantial when they are assessed by pathologists with experience of these rare tumours. Digital pathology decreases the turnaround time and facilitates access to what is essentially a multinational resource. This platform provides a template for dealing with rare tumours for which expertise is sparse.

8 years' experience with robotic thymectomy for thymomas.

BACKGROUND: The accuracy of a three-dimensional robotic-assisted videothoracoscopic approach may favor a radical resection of thymomas. The aim of this study was to demonstrate the feasibility of the robotic approach by reporting 8 years experience in a single referral center of surgical treatment of thymomas. METHODS: We retrospectively analyzed all consecutive patients who underwent a thymectomy from April 2004 to April 2012. We analyzed the procedure time, morbidity, mortality, conversions, hospitalization, freedom from recurrence, time to progression, and overall survival. RESULTS: From 2004 until 2012, a total of 138 robotic procedures for mediastinal tumors were performed in our center, of which 37 patients with a mean age of 57.3 years underwent a thymectomy for a thymoma. Histological analysis revealed four type A thymomas (10.8 %), seven type AB thymomas (18.9 %), seven type B1 thymomas (18.9 %), fourteen type B2 thymomas (37.8 %), four type B3 thymomas (10.8 %), and one thymus carcinoma (2.7 %). The Masaoka­Koga stages were as follows: stage I in twenty patients (54 %), stage IIA in five patients (13.5 %), stage IIB in eight patients (21.6 %), stage III in three patients (8.1 %), and stage IVa in one patient (2.7 %). The mean overall procedure time was 149 min (range 88­353). No surgical mortality was reported, and there were no peri-operative complications. No conversions were needed for surgical complications. In three cases, a conversion to sternotomy was preferred by the surgeon because tumor invasion in greater vessels was suspected. Two patients (5.4 %) suffered from a myasthenic crisis postoperatively and required prolonged mechanical ventilation. One patient (2.7 %) underwent a procedure for a thoracic herniation 6 months following thymectomy. The median hospitalization was 3 days. The follow-up analysis showed an overall survival of 100 % and tumor recurrence in one patient (2.7 %). CONCLUSIONS: Robotic thymectomies are safe in patients with early-stage thymomas. Robotic surgery may also be feasible for some selected advanced thymomas.

Prognostic value of proliferation, PD-L1 and nuclear size in patients with superior sulcus tumours treated with chemoradiotherapy and surgery.

AIMS: The aim of this study was to determine the relationship between proliferative activity, PD-L1 status and nuclear size changes after preoperative chemoradiotherapy (CRT) and the clinical outcome in patients with superior sulcus tumours. METHODS: Proliferative activity (MIB-1) and PD-L1 status were estimated by immunohistochemistry in the tumour cells of resection specimen in a series of 33 patients with residual tumour after trimodality therapy for a sulcus superior tumour between 2005 and 2014. A morphometric analysis of both pretreatment and post-treatment tumour materials was also performed. Results were related to disease-free survival and overall survival. RESULTS: Low proliferative activity (<20% MIB-1) was associated with better overall survival: 2-year overall survival of 73% compared with 43% and 25%, respectively, for moderate (MIB-1 20%-50%) and high (MIB-1 >50%) proliferative activity (p=0.016). A negative PD-L1 status (<1% positive tumour cells) was also associated with better overall survival (p=0.021). The mean nuclear size of normal lung tissue pneumocytes was significantly smaller compared with the mean nuclear size of tumour cells of the resection specimens (median difference -38.1; range -115.2 to 16.0; p<0.001). The mean nuclear size of tumour cells did not differ between pretreatment biopsies and resection specimens (median difference -4.6; range -75.2 to 86.7; p=0.14). Nuclear size was not associated with survival (p=0.82). CONCLUSIONS: Low proliferative activity determined by MIB-1 as well as a negative PD-L1 expression are significantly associated with better overall survival in patients with residual tumour after CRT for superior sulcus tumour.

Loose Tumor Cells in Pulmonary Arteries of Lung Adenocarcinoma Resection Specimen: No Correlation With Survival, Despite High Prevalence.

CONTEXT.­: Loose tumor cells and tumor cell clusters can be recognized in the lumen of intratumoral pulmonary arteries of resected non-small cell lung cancer specimens. It is unclear whether these should be considered tumor-emboli, and as such could predict a worsened prognosis. OBJECTIVE.­: To investigate the nature and prognostic impact of pulmonary artery intraluminal tumor cells. DESIGN.­: This multicenter study involved an exploratory pilot study and a validation study from 3 institutions. For the exploratory pilot, a retrospective pulmonary resection cohort of primary adenocarcinomas, diagnosed between November 2007 and November 2010, were scored for the presence of tumor cells, as well as potentially other cells in the intravascular spaces using hematoxylin-eosin, and cytokeratin 7 (CK7) stains. In the validation part, 2 retrospective cohorts of resected pulmonary adenocarcinomas, between January 2011 and December 2016, were included. Recurrence-free survival (RFS) and overall survival (OS) data were collected. RESULTS.­: In the pilot study, CK7+ intravascular cells, mainly tumor cells, were present in 23 of 33 patients (69.7%). The 5-year OS for patients with intravascular tumor cells was 61%, compared with 40% for patients without intravascular tumor cells (P = .19). In the validation study, CK7+ intravascular tumor cells were present in 41 of 70 patients (58.6%). The 5-year RFS for patients with intravascular tumor cells was 80.0%, compared with 80.6% in patients without intravascular tumor cells (P = .52). The 5-year OS rates were, respectively, 82.8% and 71.6% (P = .16). CONCLUSIONS.­: Loose tumor cells in pulmonary arterial lumina were found in most non-small cell lung cancer resection specimens and were not associated with a worse RFS or OS. Therefore, most probably they represent an artifact.

A Population-Based Study of Outcomes in Surgically Resected T3N0 Non-Small Cell Lung Cancer in The Netherlands, Defined Using TNM-7 and TNM-8; Justification of Changes and an Argument to Incorporate Histology in the Staging Algorithm.

OBJECTIVE: The objective was to study outcomes in patients in a population registry who were surgically staged as having pT3N0 NSCLC according to the seventh and eighth editions of the TNM staging classification. METHODS: Details of patients who underwent surgery for NSCLC staged as pT3N0M0 from 2010 to 2013 on the basis of the seventh edition of the TNM classification were retrieved from the Netherlands Comprehensive Cancer Organization. These data were next matched with corresponding pathology data from a nationwide registry. Patients were categorized into four major pT3 subgroups as follows: those with a tumor diameter more than 7 cm, those with separate tumor nodules in the same lobe (two or more nodules), those with parietal pleural invasion, and a mixed group (consisting mainly of those with a tumor diameter larger than 7 cm combined with parietal pleural invasion). RESULTS: A total of 683 patients were eligible for analysis. The 3- and 5-year overall survival (OS) rates for the subtype tumor diameter larger than 7 cm were 59.9% and 47.2%, respectively, and were comparable to the rates for the subtype with pleural invasion (50.4% and 45.3%), respectively. The mixed group had worse 3- and 5-year OS rates (37.5% and 28.7%, respectively), which were comparable to the outcomes for TNM eighth edition-staged IIIB and pT4 cases in the International Association for the Study of Lung Cancer database. For the subtype two or more nodules, the 3- and 5-year OS rates were 70.6% and 62.8%, respectively, with patients with adenocarcinoma showing a significantly better OS than did patients with squamous cell carcinoma: a 5-year OS rate of 65.1% versus 47.2%, respectively (p < 0.001), suggesting that the prognosis for the adenocarcinoma subgroup may be comparable to that for the pT2 category, whereas squamous cell carcinoma nodules can remain pT3. CONCLUSION: This population analysis of overall survival rate by pT3N0 subcategory for NSCLC suggests that histologic type is a relevant descriptor in the category two or more nodules. The findings do not support migration of the group with a tumor diameter larger than 7 cm to the category pT4in the eighth edition of the TNM classification, and they suggest that a combination of two pT3 descriptors (the mixed group) merits migration to pT4.

Pulmonary loose tumor tissue fragments and spread through air spaces (STAS): Invasive pattern or artifact? A critical review.

The concept of loose tumor tissue fragments as a pattern of invasion in lung carcinoma has recently been proposed and is included in the 2015 WHO fascicle on the classification of lung tumors, so-called "spread through airs paces" or STAS. This inclusion is controversial, as there are significant data to support that this histologic finding represents an artifact of tissue handling and processing rather than a pattern of invasion. These data are summarized in this review. These data are summarized in this review and support the conclusion that the inclusion of STAS in the WHO classification for lung cancer as a pattern of invasion was premature and erroneous. In our opinion, these tumor cell clusters or loose cells appear to be simply an artifact, although one which may or may not pinpoint to a high-grade tumor with discohesive cells and adverse prognosis.

Functional Heterogeneity of CD4+ Tumor-Infiltrating Lymphocytes With a Resident Memory Phenotype in NSCLC.

Resident memory T cells (TRM) inhabit peripheral tissues and are critical for protection against localized infections. Recently, it has become evident that CD103+ TRM are not only important in combating secondary infections, but also for the elimination of tumor cells. In several solid cancers, intratumoral CD103+CD8+ tumor infiltrating lymphocytes (TILs), with TRM properties, are a positive prognostic marker. To better understand the role of TRM in tumors, we performed a detailed characterization of CD8+ and CD4+ TIL phenotype and functional properties in non-small cell lung cancer (NSCLC). Frequencies of CD8+ and CD4+ T cell infiltrates in tumors were comparable, but we observed a sharp contrast in TRM ratios compared to surrounding lung tissue. The majority of both CD4+ and CD8+ TILs expressed CD69 and a subset also expressed CD103, both hallmarks of TRM. While CD103+CD8+ T cells were enriched in tumors, CD103+CD4+ T cell frequencies were decreased compared to surrounding lung tissue. Furthermore, CD103+CD4+ and CD103+CD8+ TILs showed multiple characteristics of TRM, such as elevated expression of CXCR6 and CD49a, and decreased expression of T-bet and Eomes. In line with the immunomodulatory role of the tumor microenvironment, CD8+ and CD4+ TILs expressed high levels of inhibitory receptors 2B4, CTLA-4, and PD-1, with the highest levels found on CD103+ TILs. Strikingly, CD103+CD4+ TILs were the most potent producers of TNF-α and IFN-γ, while other TIL subsets lacked such cytokine production. Whereas, CD103+CD4+PD-1low TILs produced the most effector cytokines, CD103+CD4+PD-1++ and CD69+CD4+PD-1++ TILs produced CXCL13. Furthermore, a large proportion of TILs expressed co-stimulatory receptors CD27 and CD28, unlike lung TRM, suggesting a less differentiated phenotype. Agonistic triggering of these receptors improved cytokine production of CD103+CD4+ and CD69+CD8+ TILs. Our findings thus provide a rationale to target CD103+CD4+ TILs and add co-stimulation to current therapies to improve the efficacy of immunotherapies and cancer vaccines.

Feasibility of pathology-correlated lung imaging for accurate target definition of lung tumors.

PURPOSE: To accurately define the gross tumor volume (GTV) and clinical target volume (GTV plus microscopic disease spread) for radiotherapy, the pretreatment imaging findings should be correlated with the histopathologic findings. In this pilot study, we investigated the feasibility of pathology-correlated imaging for lung tumors, taking into account lung deformations after surgery. METHODS AND MATERIALS: High-resolution multislice computed tomography (CT) and positron emission tomography (PET) scans were obtained for 5 patients who had non-small-cell lung cancer (NSCLC) before lobectomy. At the pathologic examination, the involved lung lobes were inflated with formalin, sectioned in parallel slices, and photographed, and microscopic sections were obtained. The GTVs were delineated for CT and autocontoured at the 42% PET level, and both were compared with the histopathologic volumes. The CT data were subsequently reformatted in the direction of the macroscopic sections, and the corresponding fiducial points in both images were compared. Hence, the lung deformations were determined to correct the distances of microscopic spread. RESULTS: In 4 of 5 patients, the GTV(CT) was, on average, 4 cm(3) ( approximately 53%) too large. In contrast, for 1 patient (with lymphangitis carcinomatosa), the GTV(CT) was 16 cm(3) ( approximately 40%) too small. The GTV(PET) was too small for the same patient. Regarding deformations, the volume of the well-inflated lung lobes on pathologic examination was still, on average, only 50% of the lobe volume on CT. Consequently, the observed average maximal distance of microscopic spread (5 mm) might, in vivo, be as large as 9 mm. CONCLUSIONS: Our results have shown that pathology-correlated lung imaging is feasible and can be used to improve target definition. Ignoring deformations of the lung might result in underestimation of the microscopic spread.

A Prospective Study of Loose Tissue Fragments in Non-Small Cell Lung Cancer Resection Specimens: An Alternative View to "Spread Through Air Spaces".

The World Health Organization Classification of Lung Tumors considers "Spread Through Air Spaces" a form of invasion in lung adenocarcinoma. The recently described spread of free-floating cell clusters during lung specimen sectioning, otherwise known as "Spread Through A Knife Surface," represents an ex vivo artifact. The purpose of this study was to prospectively investigate the presence and frequency of these free-floating tumor cell clusters in surgically resected lung cancer specimens and their possible relation to gross examination procedures. A prospective, multi-institutional study of non-small cell lung cancer resection specimen was undertaken. At prosection the first cut was made with a clean knife; the second cut was made in a parallel plane to the first. Four tissue blocks were taken from upper and lower parts of first and second cuts. Hematoxylin and eosin-stained slides were examined for displaced benign and/or malignant tissue fragments. Forty-four resection specimens were studied. The mean number of tumor clusters for blocks 1 to 4 was 0.36, 1.44, 1.86, and 1.95, respectively, and for benign fragments was 0.11, 0.11, 0.13, and 0.25, respectively. Almost all cell clusters were intra-alveolar. Comparison of tumor cell clusters in block 1 with blocks 2 to 4 was significant with P-values (Friedman test for repeated measures 0.03) 0.031, 0.02, and 0.05, respectively. Overall 93% of the loose tissue fragments could be explained by mechanical forces associated with tissue handling. While the 2015 World Health Organization Classification of Lung Tumors recognizes Spread Through Air Spaces as a form of lung cancer invasion, such is debatable and in many instances likely represents mechanical artifact, including dissemination along the prosecting knife blade.

Pseudomelanosis of the bladder: a case report.

BACKGROUND: Pseudomelanosis is due to deposition of pseudomelanin and is best known as the entity pseudomelanosis coli. However, pseudomelanosis in the urinary tract has never been described. Pigmentation of the urothelium, known as melanosis vesica, is characterized by deposition of melanin pigment granules without signs of atypia. Simple (true) melanosis of the bladder is uncommon. CASE: A 52-year-old man presented with macroscopic hematuria. Cystoscopy and microscopic evaluation revealed pigmentation of the bladder urothelium diagnosed as pseudomelanosis vesica due to deposits of melaninlike pigment in the absence of detectable melanocytes and detectable by urine cytology. CONCLUSION: Pseudomelanosis vesica is a benign lesion that has never before been observed in the urinary tract.

Ex Vivo Artifacts and Histopathologic Pitfalls in the Lung.

CONTEXT: Surgical and pathologic handling of lung physically affects lung tissue. This leads to artifacts that alter the morphologic appearance of pulmonary parenchyma. OBJECTIVE: To describe and illustrate mechanisms of ex vivo artifacts that may lead to diagnostic pitfalls. DESIGN: In this study 4 mechanisms of ex vivo artifacts and corresponding diagnostic pitfalls are described and illustrated. RESULTS: The 4 patterns of artifacts are: (1) surgical collapse, due to the removal of air and blood from pulmonary resections; (2) ex vivo contraction of bronchial and bronchiolar smooth muscle; (3) clamping edema of open lung biopsies; and (4) spreading of tissue fragments and individual cells through a knife surface. Morphologic pitfalls include diagnostic patterns of adenocarcinoma, asthma, constrictive bronchiolitis, and lymphedema. CONCLUSION: Four patterns of pulmonary ex vivo artifacts are important to recognize in order to avoid morphologic misinterpretations.

Cat scratch disease, a rare cause of hypodense liver lesions, lymphadenopathy and a protruding duodenal lesion, caused by Bartonella henselae.

A 46-year-old woman presented with right upper abdominal pain and fever. At imaging, enlarged peripancreatic and hilar lymph nodes, as well as hypodense liver lesions, were detected, suggestive of malignant disease. At endoscopy, the mass adjacent to the duodenum was seen as a protruding lesion through the duodenal wall. A biopsy of this lesion, taken through the duodenal wall, showed a histiocytic granulomatous inflammation with necrosis. Serology for Bartonella henselae IgM was highly elevated a few weeks after presentation, consistent with the diagnosis of cat scratch disease. Clinical symptoms subsided spontaneously and, after treatment with azithromycin, the lymphatic masses, liver lesions and duodenal ulceration disappeared completely.

Enterocolic lymphocytic phlebitis: an oncologic surgical resection without a preoperative pathologic diagnosis.

A patient with complaints of an abdominal (mesenteric) mass is presented. Differential diagnosis included neoplastic processes, such as malignant lymphoma, desmoid tumour, a carcinoid or a gastro-intestinal stromal cell tumour. An oncological resection was performed. Despite the malignant appearance of the tumour no malignancy was found with histopathological examination. Vasculitic lesions were seen in venous structures, resembling veno-occlusive disease with signs of recanalization and with the presence of inflammatory cells, mainly lymphocytes. A diagnosis of enterocolic lymphocytic phlebitis was made. This benign condition can mimic malignancy, necessitating a wide excision, also because obtaining a pre-operative histopathological diagnosis is hardly possible.

[A clinically unrecognised and persistent facial folliculitis: herpes folliculitis]. / Een klinisch onbegrepen en persisterende folliculitis in het gelaat: herpes folliculitis.

A 33-year-old woman presented with a 5-year history of a relapsing erythematous, indurated plaque on the left cheek. Herpes simplex virus (HSV) immunostain revealed the presence of HSV in the follicular and perifollicular keratinocytes. After oral treatment with valaciclovir for a period of 3 months the lesion disappeared without leaving a scar. At the last check-up, no recurrence had occurred. Herpes folliculitis has various clinical presentations. In rare cases it mimics a pseudolymphoma, as was the case for this patient. A viral aetiology, such as HSV or varicella-zoster virus, should be considered in patients with folliculitis, especially when the condition does not respond to antibacterial and antifungal therapy.

Fatal sepsis after uterine artery embolization with microspheres.

A case report of fatal sepsis after uterine artery embolization (UAE) with microspheres is presented. At autopsy, microspheres were found not only in arteries in the leiomyomata and myometrium but also in the parametria and the vagina, leading to a necrotic vaginal wall and uterine cervix. At present, polyvinyl alcohol particles are usually used in UAE. Recently, study results of the use of microspheres in embolization procedures have become available. The rationale for the choice of a specific embolization particle and the clinical implications of possible sepsis after UAE are discussed.