Detection of NTRK gene fusions in solid tumors: recommendations from a Latin American group of oncologists and pathologists.

NTRK gene fusions have been detected in more than 25 types of tumors and their prevalence is approximately 0.3% in solid tumors. This low prevalence makes identifying patients who could benefit from TRK inhibitors a considerable challenge. Furthermore, while numerous papers on the evaluation of NTRK fusion genes are available, not all countries have guidelines that are suitable for their setting, as is the case with Latin America. Therefore, a group of oncologists and pathologists from several countries in Latin America (Argentina, Chile, Ecuador, Mexico, Peru and Uruguay) met to discuss and reach consensus on how to identify patients with NTRK gene fusions in solid tumors. To do so, they developed a practical algorithm, considering their specific situation and limitations.

[Anaplastic large cell lymphoma associated with breast implants, diagnosed by fine needle aspiration. Report of one case]. / Linfoma anaplásico de células grandes asociado a implantes mamarios diagnosticado mediante punción por aguja fina. Caso clínico.

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a rare type of non-Hodgkin T-cell lymphoma, recently defined in the 2016 World Health Organization (WHO) classification of lymphoid neoplasms. It occurs more commonly when textured implants are used and appears clinically as a late seroma. Cytologically, these lesions are composed of large atypical cells with pleomorphic nucleus and an immunophenotype positive for T cell markers and CD30, and negative for ALK1. We report a 56-years-old woman with breast implants who developed a periprosthetic seroma three years after surgery. A fine needle aspiration of the lesion was carried out. Cytology and the immunocytochemical study revealed cells compatible with BIA-ALCL. The flow cytometric study was negative. Excisional biopsy of the capsule was performed, observing that the neoplastic cells were confined to the inner surface of the capsule. Imaging studies did not find evidence of disseminated disease. The present case demonstrates the importance of the study of any late periprosthetic effusion, which can be performed using fine needle aspiration.

Mapping the triglyceride distribution in NAFLD human liver by MALDI imaging mass spectrometry reveals molecular differences in micro and macro steatosis.

Hepatic lipid accumulation, mainly in the form of triglycerides (TGs), is the hallmark of non-alcoholic fatty liver disease (NAFLD). To date, the spatial distribution of individual lipids in NAFLD-affected livers is not well characterized. This study aims to map the triglyceride distribution in normal human liver samples and livers with NAFLD and cirrhosis with imaging mass spectrometry (MALDI IMS). Specifically, whether individual triglyceride species differing by fatty acid chain length and degree of saturation correlate with the histopathological features of NAFLD as identified with classical H&E. Using a recently reported sodium-doped gold-assisted laser desorption/ionization IMS sample preparation, 20 human liver samples (five normal livers, five samples with simple steatosis, five samples with steatohepatitis, and five samples with cirrhosis) were analyzed at 10-µm lateral resolution. A total of 24 individual lipid species, primarily neutral lipids, were identified (22 TGs and two phospholipids). In samples with a low level of steatosis, TGs accumulated around the pericentral zone. In all samples, TGs with different degrees of side-chain saturation and side-chain length demonstrated differential distribution. Furthermore, hepatocytes containing macro lipid droplets were highly enriched in fully saturated triglycerides. This enrichment was also observed in areas of hepatocyte ballooning in samples with steatohepatitis and cirrhosis. In conclusion, macro lipid droplets in NAFLD are enriched in fully saturated triglycerides, indicating a possible increase in de novo lipogenesis that leads to steatohepatitis and cirrhosis.

Programmed cell death ligand-1 expression in tumor and immune cells is associated with better patient outcome and decreased tumor-infiltrating lymphocytes in uveal melanoma.

Programmed cell death-1/ligand (PD-1/PD-L1) interaction negatively regulates T cell activity. PD-L1 expression in tumor cells, antigen-presenting cells, and lymphocytes of the tumor microenvironment is associated with response to treatment with PD-1/PD-L1 inhibitors, but there is still debate on the cutoff value that correlates with responders. In uveal melanoma (UM), 40% of patients will develop liver metastases and, amongst them, 90% will succumb to their disease. The aim of this study was to analyze PD-L1 expression as a prognostic marker and as a possible therapeutic target for UM. Sixty-seven enucleated eyes from UM patients with relevant clinical information were analyzed. Univariate and multivariate analysis were used to evaluate association of PD-L1 with survival. PD-L1 expression was positive relatively to tumor cells, immune cells, and the tumor and tumor-infiltrating immune cell group scoring in 46, 34 and 55% of the cases, respectively. On univariate analysis, tumor cells and the tumor and tumor-infiltrating immune cell group PD-L1 expression was associated with a longer metastasis-free survival (P = 0.04 and P = 0.007). However, on multivariate analysis, only the tumor and tumor-infiltrating immune cell group positivity was associated with longer metastasis-free survival (P = 0.01). Furthermore, tumor cells and the tumor and tumor-infiltrating immune cell group PD-L1 expression was associated with decreased tumor-infiltrating lymphocytes (P = 0.02). PD-L1, when expressed in uveal melanoma, is associated with better patient outcome and decreased tumor-infiltrating lymphocytes. These results support the consideration of anti-PD-1/PD-L1 therapy in uveal melanoma. To determine the best cutoff value, further studies from patients enrolled in clinical trials treated with PD-1/PD-L1 inhibitors are necessary.

Blue-light filtering alters angiogenic signaling in human retinal pigmented epithelial cells culture model.

BACKGROUND: Light exposure and more specifically the spectrum of blue light contribute to the oxidative stress in Age-related macular degeneration (AMD). The purpose of the study was to establish whether blue light filtering could modify proangiogenic signaling produced by retinal pigmented epithelial (RPE) cells under different conditions simulating risk factors for AMD. METHODS: Three experiments were carried out in order to expose ARPE-19 cells to white light for 48 h with and without blue light-blocking filters (BLF) in different conditions. In each experiment one group was exposed to light with no BLF protection, a second group was exposed to light with BLF protection, and a control group was not exposed to light. The ARPE-19 cells used in each experiment prior to light exposure were cultured for 24 h as follows: Experiment 1) Normoxia, Experiment 2) Hypoxia, and Experiment 3) Lutein supplemented media in normoxia. The media of all groups was harvested after light exposure for sandwich ELISA-based assays to quantify 10 pro-angiogenic cytokines. RESULTS: A significant decrease in angiogenin secretion levels and a significant increase in bFGF were observed following light exposure, compared to dark conditions, in both normoxia and hypoxia conditions. With the addition of a blue light-blocking filter in normoxia, a significant increase in angiogenin levels was observed. Although statistical significance was not achieved, blue light filters reduce light-induced secretion of bFGF and VEGF to near normal levels. This trend is also observed when ARPE-19 cells are grown under hypoxic conditions and when pre-treated with lutein prior to exposure to experimental conditions. CONCLUSIONS: Following light exposure, there is a decrease in angiogenin secretion by ARPE-19 cells, which was abrogated with a blue light - blocking filter. Our findings support the position that blue light filtering affects the secretion of angiogenic factors by retinal pigmented epithelial cells under normoxic, hypoxic, and lutein-pretreated conditions in a similar manner.

Pretreatment of RPE Cells with Lutein Can Mitigate Bevacizumab-Induced Increases in Angiogenin and bFGF.

PURPOSE: To determine whether pretreatment of retinal pigmented epithelial (RPE) cells with lutein can affect the response of cells to bevacizumab therapy. METHODS: One human RPE cell line (ARPE-19) was used for all experiments. The cells were treated with lutein in different concentrations (0.01, 0.1, 1, 10, or 100 µg/ml). After 24 h, all plates were treated with bevacizumab (0.25 mg/ml). Media were harvested 24 h later for sandwich ELISA-based angiogenesis arrays. A Quantibody Human Angiogenesis Array was used in order to quantify the secretion of the following 10 proangiogenic cytokines: angiogenin, ANG2, EGF, bFGF, HB-EGF, PDGF-BB, leptin, PIGF, HGF and VEGF. RESULTS: Treatment with bevacizumab alone led to a significant decrease in VEGF, as well as a significant increase in angiogenin and bFGF. Pretreatment with 0.1 and 1.0 µg/ml of lutein led to significant decreases in both bFGF and angiogenin following treatment with bevacizumab compared to bevacizumab treatment alone. Lutein alone did not modify the secretion of proangiogenic cytokines. CONCLUSIONS: Pretreatment of human RPE cells in culture with specific doses of lutein prior to bevacizumab treatment mitigated the increase in bFGF and angiogenin caused by bevacizumab monotherapy.

Eyelid Mycetoma Masquerading as Sebaceous Carcinoma.

A 56-year-old Asian woman presented with an upper eyelid mass. The lesion was exposed after eversion of the eyelid revealing a thickened tarsus with yellowish areas. Working diagnosis was sebaceous carcinoma. Biopsy was performed. Histopathological studies showed a mycotic eumycetoma with Splendore-Hoeppli phenomena and - microbiologic cultures grew Scedosporium apiospermum. The patient was started on voriconazole 200 mg po bid with adequate serum levels. A complete response was observed after 18 weeks of voriconazole therapy. To the best of our knowledge, this is the first published case of S. apiospermum eumycotic mycetoma of the eyelid. It is important to consider mycotic infection in the differential diagnosis of eyelid tumors even in healthy patients.

Conjunctival Melanoma With Morphologic Diversity and Orbital Invasion.

A 68-year-old male with a previous history of 3 dysplastic skin nevi was referred to ophthalmology for a 1-year history of a progressive growth of a firm nodule in the lower left eyelid. Examination revealed a firm nodule in the inferior anterior orbit and mild conjunctival pigmentation on the left inferior fornix. A conjunctival incisional biopsy was taken, showing a melanoma. Because of the infiltration by the mass of the orbit on magnetic resonance imaging, an exenteration was performed. Histopathological analysis showed a unique conjunctival melanoma showing morphological diversity; specifically, a pattern characteristic of conjunctival melanoma, and the concurrent presence of staghorn patterns, signet-ring cells, and rosettoid patterns. Seven years of follow-up shows that the patient is alive with no further metastasis or recurrence. This report represents the first documented case of multiple morphologic patterns within a conjunctival melanoma.

Immunohistochemical Analysis of PDGFR-α, PDGFR-ß and c-Abl in Retinoblastoma: Potential Therapeutic Targets.

BACKGROUND: Our laboratory previously reported that imatinib mesylate (IM) has an inhibitory effect on two retinoblastoma (Rb) cell lines in vitro. AIMS: The purpose of this project was to determine the immunoexpression of platelet-derived growth factor receptor (PDGFR)-α, PDGFR-ß and c-Abl in 61 human samples of Rb to determine if IM-sensitive receptors are present. Additionally, this paper seeks to establish a correlation between the expression of PDGFR, c-Abl and the histopathological prognosis. METHODS: Sixty-one paraffin-embedded Rbs were collected from the Henry C. Witelson Ocular Pathology Registry. PDGFR-α, PDGFR-ß and c-Abl immunostaining was performed according to the protocol provided by Ventana Medical System Inc. Immunoreactivity was correlated with the presence or absence of invasion into the choroid and optic nerve. RESULTS: Overall, c-Abl expression was identified in 50 out of 61 specimens (81.97%), PDGFR-α was identified in 20 out of 60 specimens (33.33%) and PDGFR-ß expression was identified in 57 out of 61 specimens (93.44%). Histopathological prognosis was not correlated with immunoreactivity except in the case of PDGFR-ß. CONCLUSIONS: Rb is a cancer that expresses PDGFR-α, PDGFR-ß and c-Abl, which are known targets of IM. These markers may be responsible for the documented therapeutic effect of IM on Rb cell lines.

Pericyte Status in Routinely Discarded Vitrectomy Samples May Be an Early Marker of Diabetic Retinopathy.

BACKGROUND: Diabetic retinopathy (DR) is the leading cause of blindness among the working-age population. The earliest morphological manifestation of the disease is pericyte loss, as shown by animal models. AIMS: The purpose of this study was to evaluate the presence of pericytes in vitreous samples (VS) from diabetic and nondiabetic patients. METHODS: VS from 125 patients with and without diabetes were analyzed. Thirty-three of the VS contained blood vessels and were therefore included in further analysis. Pericyte status was evaluated using α-smooth muscle actin and quantified using the following scoring system: total loss (3), >50% loss (2), <50% loss (1), and no loss (0). RESULTS: Of the 33 VS, 29 samples were from patients with diabetes and 4 from nondiabetic patients. Six diabetic cases had a score of 1, 8 diabetic cases had a score of 2, and 15 cases had a score of 3. A positive correlation between glycemia levels and pericyte loss was observed (p = 0.0016; Spearman's r = 0.61). Moreover, all nondiabetic cases had a score of 0 (sensitivity and specificity = 100%). CONCLUSION: Pericyte loss in VS might be a sensitive and specific marker of DR that correlates with glycemia levels. Furthermore, VS, which are currently discarded, may contain valuable information for diabetic management.

[Conjunctival rhinosporidiois diagnosed in a biopsy specimen]. / Rinosporidiosis conjuntival diagnosticada mediante estudio histopatológico.

11 years old girl, from south region of Chile, without history of travels outside Chile nor the province, complaints of red eye with blepharitis and blood-tingued epiphora. Eye exam revealed a pseudomembrane. Clinical diagnosis was folicular conjunctivitis. A surgical removal was performed and the lesion sent to biopsy analysis. On microscopic examination numerous 50-150 microm cysts with keratinous wall and numerous endospores were found. Rinosporidiosis is an infection caused by Rhinosporidium seeberi that frecuently affects nasal cavity but could infect eye, urogenital tract and airways. This infections is considered endemic in Asia and Africa, but it is very important to have the suspicious among polyps in these areas because travel to endemic areas is become more frecuently.

Low Expression of Vitamin D Receptor in Patients With Dry Eye Disease.

PURPOSE: This study aimed to compare the expression of vitamin D receptor (VDR) on the ocular surface of patients with dry eye disease (DED) and controls without ophthalmological pathologies. METHODS: Patients with DED without previous treatment were studied and compared with healthy subjects. Ocular Surface Disease Index assessement and ocular surface cytology were performed in all patients. The immunohistochemical expression of VDR was evaluated using fully automated immunohistochemistry. The evaluation involved multiplying the percentage of nuclear-labeled cells (0-100) by their intensity (0-3), resulting in a score ranging from 0 to 300 (VDR H-score). Squamous metaplasia was morphologically evaluated using liquid-phase cytology with Papanicolaou/periodic acid-Schiff staining using Nelson's grade (scale 0-3, higher grade to higher metaplastic change). RESULTS: Eighteen patients with DED without previous treatment and 10 healthy subjects were studied. Squamous metaplasia was observed in 74% of patients with DED, in contrast to 0% in the control group. In patients with DED, there was a lower expression of VDR than in the control group (VDR H-score: 11.2 ± 13.9 vs. 80.9 ± 56; P = 0.0001). Furthermore, an inverse correlation was observed between Nelson grade and VDR H-score ( P = 0.0001, rs = -0.71). No correlation was observed between Ocular Surface Disease Index and VDR H-score. CONCLUSIONS: This is the first study to evaluate the VDR in patients with DED. These patients presented with a lower expression of VDR than healthy subjects. No correlation was found with more severe symptoms. Patients with DED also had a higher frequency of squamous metaplasia.

Management of periocular keratinocyte carcinomas with Mohs micrographic surgery and predictors of complex reconstruction: a retrospective study.

BACKGROUND: Skin cancer is the most frequent cancer worldwide and the most frequent periocular tumor. Keratinocyte Carcinomas (KC) located in periorificial areas, such as periocular tumors, are considered high-risk tumors. Mohs Micrographic Surgery (MMS) is considered the first line for the treatment of high-risk KC, providing a lower recurrence rate than conventional wide excision. OBJECTIVE: To describe the clinical-pathological features of periocular KC treated with MMS in a tertiary university center in Chile. METHODS: A single-center, retrospective study of patients with KC located on the periocular area, that underwent MMS between 2017‒2022. MMS details were recorded. RESULTS: One hundred thirteen patients with periocular carcinomas were included. The mean age was 59 ± 13 years; 52% were women. The most frequent location was the medial canthus (53%), followed by the lower eyelid (30.1%). The most frequent BCC histology was the nodular variant (59.3%). Regarding MMS, the average number of stages was 1.5 ± 0.7, and 54% of the cases required only 1 stage to achieve clear margins. To date, no recurrence has been reported. Tumors larger than 8.5 mm in largest diameter or 43.5 mm2 were more likely to require complex reconstruction. STUDY LIMITATIONS: Retrospective design and a relatively low number of patients in the SCC group. Possible selection bias, as larger or more complex cases, may have been referred to oculoplastic surgeons directly. CONCLUSION: The present study confirms the role of MMS for the treatment of periocular KCs. Periocular KCs larger than 8.5 mm might require complex reconstruction. These results can be used to counsel patients during pre-surgical visits.

Two Decades of Thyroid Nodule Cytology in Children: Malignancy Risk Assessment at a Tertiary Care Center.

INTRODUCTION: Pediatric thyroid nodules exhibit higher malignancy rates compared to adults and are associated with increased incidences of metastases and recurrences. The American Thyroid Association recommends surgery for indeterminate thyroid biopsies in children based on these higher malignancy risks, though this approach may lead to overtreatment. However, there remains a lack of comprehensive pediatric data to inform clinical decisions. This study examines the risk of malignancy (ROM) in pediatric thyroid nodules using the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) and assesses the diagnostic accuracy of fine-needle aspiration (FNA) biopsy compared to histological outcomes. METHODS: A retrospective cross-sectional analysis was performed on patients under 19 years with thyroid nodules who underwent FNA and thyroidectomy at a tertiary care center. The sensitivity, specificity, positive predictive value, negative predictive value, and ROM of cytological biopsies were evaluated using TBSRTC criteria, with histology serving as the gold standard. Two analyses were conducted to assess diagnostic accuracy: (a) TBSRTC II as negative and TBSRTC VI as positive and (b) TBSRTC II as negative with TBSRTC V and VI as positive. For neoplasia detection, TBSRTC II was deemed negative, while TBSRTC IV, V, and VI were considered positive. TBSRTC categories III and I were excluded from the performance analysis and evaluated separately. Follicular neoplasm or lesions suspicious for follicular neoplasm (FN/SFN) were treated as positive outcomes, correlated with the presence of adenoma or carcinoma in the surgical specimen. RESULTS: Of 75 nodules from 73 patients, 28 (37.3%) were benign and 47 (62.6%) malignant. No significant differences in gender or age were noted between groups. The ROM in each TBSRTC was Bethesda I 0/2, 0%; II 0/13, 0%; III 2/7, 29%: IV 6/14, 43%; V 10/10, 100%, and VI 29/29, 100%. A sensitivity of 78.38% and specificity of 100% for FNA in detecting malignancy was found, with an even higher sensitivity (100%) for detecting neoplasia in TBSRTC IV. CONCLUSIONS: This study reveals that indeterminate thyroid nodules in pediatric patients exhibit a higher rate of malignancy compared to adults, yet align with rates previously reported in the pediatric population. These findings highlight the critical need for guidelines tailored specifically to the management of thyroid nodules and thyroid cancer in children.

Neoadjuvant chemoradiation therapy for borderline pancreatic adenocarcinoma: report of two cases.

Pancreatic cancer remains as one of the most aggressive human neoplasms, with overall poor survival rates. Radical surgery of the primary lesion is the best option for treatment. Borderline resectable pancreatic tumors (BRPT), defined as partial involvement of peripancreatic vasculature, may benefit from neoadjuvant therapy. We report on the first two BRPT cases treated with neoadjuvant chemoradiation at our institution. Preoperative CT and MRI demonstrated pancreatic tumors encasing the porto-mesenteric confluence suggestive of BRPT. Patients received neoadjuvant chemotherapy (gemcitabine/cisplatin), followed by radiochemotherapy. After treatment, follow-up images demonstrated tumor downsize, allowing for the tumors to be considered then as resectable. They underwent partial pancreatoduodenectomies (Whipple procedure). In case 1, histopathology revealed a complete, margin-free resection, whereas in case 2 there was a complete pathological response, with no evidence of residual tumor. According to the literature, our initial experience using neoadjuvant chemoradiotherapy on BRPT allowed us to downsize the tumor and, subsequently, to perform a curative surgery.

PRAME/MELAN-A double immunostaining as a diagnostic tool for conjunctival melanocytic lesions: A South American experience.

INTRODUCTION: PRAME (PReferentially expressed Antigen in Melanoma) is an antigen that is predominantly expressed in human melanomas. In cutaneous melanocytic lesions, PRAME expression is associated with malignancy. The objective of this study was to evaluate the co-expression of PRAME and Melan A to evaluate their diagnostic value in different conjunctival melanocytic lesions (CML). METHODS: 37 CML (23 nevi, 9 primary acquired melanosis (PAM), and 5 conjunctival melanomas) were evaluated by immunohistochemistry for PRAME and Melan-A. The percentage of melanocytic cells co-expressing PRAME and Melan-A was qualitatively evaluated as follows: negative, 0%; 1 + , 1-25%; 2 + , 26-50%; 3 + , 51-75% and 4 + , ≥ 76%. RESULTS: Of the invasive melanoma cases, 80% showed a 4 + pattern of marking, whereas 20% showed a 3 + pattern. 11% of the PAMs showed a 4 + pattern and 88.9% showed a 1 + pattern. All the nevi showed a 1 + pattern. The sensitivity and specificity of PRAME 4 + for differentiating high-grade CML from the benign and low-grade grouped CML are 93% and 100%, respectively. CONCLUSION: PRAME/MELAN-A double immunostain is particularly useful to differentiate benign from malignant conjunctival melanocytic lesions.

ThyroidPrint®: clinical utility for indeterminate thyroid cytology.

Molecular testing contributes to improving the diagnosis of indeterminate thyroid nodules (ITNs). ThyroidPrint® is a ten-gene classifier aimed to rule out malignancy in ITN. Post-validation studies are necessary to determine the real-world clinical benefit of ThyroidPrint® in patients with ITN. A single-center, prospective, noninterventional clinical utility study was performed, analyzing the impact of ThyroidPrint® in the physicians' clinical decisions for ITN. Demographics, nodule characteristics, benign call rates (BCRs), and surgical outcomes were measured. Histopathological data were collected from surgical biopsies of resected nodules. Of 1272 fine-needle aspirations, 109 (8.6%) were Bethesda III and 135 (10.6%) were Bethesda IV. Molecular testing was performed in 155 of 244 ITN (63.5%), of which 104 were classified as benign (BCR of 67.1%). After a median follow-up of 15 months, 103 of 104 (99.0%) patients with a benign ThyroidPrint® remained under surveillance and one patient underwent surgery which was a follicular adenoma. Surgery was performed in all 51 patients with a suspicious for malignancy as per ThyroidPrint® result and in 56 patients who did not undergo testing, with a rate of malignancy of 70.6% and 32.1%, respectively. A higher BCR was observed in follicular lesion of undetermined significance (87%) compared to atypia of undetermined significance (58%) (P < 0.05). False-positive cases included four benign follicular nodules and six follicular and four oncocytic adenomas. Our results show that, physicians chose active surveillance instead of diagnostic surgery in all patients with a benign ThyroidPrint® result, reducing the need for diagnostic surgery in 67% of patients with preoperative diagnosis of ITN.

Leukocytoclastic vasculitis as early manifestation of Epstein-Barr virus-positive diffuse large B-cell lymphoma of the elderly.

Extensive necrotizing vasculitis (ENV) is a rare paraneoplastic phenomenon, and the majority of cases reported are associated with hematolymphoid neoplasms. Histologically, most cases of ENV represent leukocytoclastic vasculitis (LCV). Here we report the clinicopahological features of a 68-year-old man with ENV associated to a Epstein Barr virus-positive diffuse large B-cell lymphoma (EBV+DLBCL) of the elderly, a newly recognized lymphoproliferative disorder, most likely representing a paraneoplastic manifestation. The patient was treated with standard chemotherapy regimen for malignant lymphoma. Due to the extensive involvement of the extremities by ENV, surgical debridement was not feasible and a novel therapy based on CHITOSAN apposits was initiated with overall good response and subsequent re-epithelization of the skin lesions. The patient died of sepsis secondary to a Pseudomona pneumonia 17 months after diagnosis.