Squamous Differentiation in the Thyroid: Metaplasia, Neoplasia, or Bystander?

Background. Squamous differentiation within the thyroid is seen in a variety of settings. Squamous epithelium is non-native to the thyroid, and its debated origins span reactive metaplasia and developmental/embryologic remnants. Despite a lack of clarity as to its evolution, squamous epithelium may be associated with both neoplastic and non-neoplastic processes. Methods. Thyroid pathology reports spanning a 30-year period were reviewed for terms indicating squamous features. Associated diagnostic and clinical information was collated. Results. Four hundred and twenty seven of 17,452 (2.4%) thyroid surgical pathology cases during this period utilized terminology indicating squamous differentiation including 243 malignant (58%) and 178 benign (42%) diagnoses. There were 111 (26%) primary thyroid malignancies with squamous differentiation, 116 (28%) malignancies of non-thyroid origin including local extension from nearby cancers, and 16 (4%) malignancies of uncertain primary. Most benign lesions were non-neoplastic (84%). The minor subset representing benign neoplasia was interpreted as secondary reactive changes. Conclusion. While squamous differentiation is seen routinely in the thyroid, it is most commonly reported in malignancy. For primary thyroid malignancies reported to demonstrate a squamous component, biologically aggressive tumors were overrepresented. Available evidence suggests that multiple pathways may contribute to the presence of squamous epithelium in the thyroid including metaplasia of mature follicular cells, development from established embryonic remnants, or inception in putative, incompletely characterized stem-like cells. Our retrospective review presents an institutional landscape from which further investigation into the frequency and unique histologic and molecular context of intrathyroidal squamous differentiation as a driver or terminal event in thyroid pathophysiology.

Opportunities for Drug Repurposing of Serotonin Reuptake Inhibitors: Potential Uses in Inflammation, Infection, Cancer, Neuroprotection, and Alzheimer’s Disease Prevention

Serotonin reuptake inhibitors (SRIs) are safe and widely used for a variety of indications including depressive disorders, anxiety, and chronic pain. Besides inhibiting the serotonin transporter, these medications have broad-spectrum properties in many systems. Their roles have been studied in cancer, Alzheimer’s disease, and infectious processes. The COVID-19 pandemic highlighted the importance of drug repurposing of medications already in use. We conducted a narrative review of current evidence and ongoing research on drug repurposing of SRIs, with a focus on immunomodulatory, antiproliferative, and neuroprotective activity. SRIs may have clinical use as repurposed agents for a wide variety of conditions including but not limited to COVID-19, Alzheimer’s disease, and neoplastic processes. Further research, particularly randomized controlled trials, will be necessary to confirm the utility of SRIs for new indications.

Distinguishing Intramedullary Spinal Cord Neoplasms from Non-Neoplastic Conditions by Analyzing the Classic Signs on MRI in the Era of AI

: Intramedullary lesions can be challenging to diagnose given the wide range of possible pathologies. Each lesion has unique clinical and imaging features, which are best evaluated on magnetic resonance imaging. Radiological imaging is unique with rich, descriptive patterns and classic signs—which are often metaphorical. In this review, we present a collection of classic MRI signs, ranging from neoplastic to non-neoplastic lesions, within the spinal cord. The differential diagnosis (DD) of intramedullary lesions can be narrowed down by careful analysis of the classic signs and pattern of involvement in the spinal cord. Furthermore, the signs are illustrated memorably with emphasis on the pathophysiology, mimics and pitfalls. Artificial intelligence (AI) algorithms, particularly deep learning, have made remarkable progress in image recognition tasks. The classic signs and related illustrations can enhance a pattern recognition approach in diagnostic radiology. Deep learning can potentially be designed to distinguish neoplastic from non-neoplastic processes by pattern recognition of the classic MRI signs.

Hematolymphoid Neoplasms in Serous Effusions: Morphological Spectrum, Distribution, and Role of Ancillary Techniques—A Retrospective Analysis of 75 cases

Introduction Involvement of body fluids can occur at the time of diagnosis or during the disease course of hematolymphoid neoplasms. Cytodiagnosis of malignant effusion is important in effective clinical management. Objectives (1) The aims of the study were to determine the frequency of distribution of various hematolymphoid neoplasms involving body fluids, (2) to study the morphology of hematolymphoid neoplasms in fluids, and (3) to assess the role of ancillary techniques in the diagnosis. Materials and Methods In this retrospective study, all cases of hematolymphoid neoplasms involving body fluids diagnosed from January 2016 to December 2018 were evaluated. Results During the 3-year period, there were 75 cases of hematological malignancies involving body fluids. These included 48 male patients and 27 female patients. Pleural fluid was involved in majority of cases (56 cases; 74.67%), followed by ascitic fluid (17 cases; 22.67%), and pericardial fluid (2 cases; 2.67%). High cellularity, monotonous population of cells, high nuclear-cytoplasmic (N/C) ratio, indentation/irregularity of nuclear membrane, immature chromatin/irregular clumping of chromatin, increased mitosis, and karyorrhexis were the key features which helped to differentiate between reactive and neoplastic processes. There were 35 cases of B-cell neoplasms, 33 cases of T-cell neoplasms, and seven cases of myeloid neoplasms involving body cavity fluids. T-lymphoblastic lymphoma was the most common subtype (29 cases; 38.7%), followed by diffuse large B-cell lymphoma (DLBCL) (12 cases; 16%). In 53 cases, effusion was present in the initial presentation itself. Initial diagnosis was made in effusion cytology in 25 cases (33.33% of the total), with the help of flow cytometry in 20 cases, and immunohistochemistry (IHC) in cell blocks in five cases. Conclusion Diagnosis of hematolymphoid neoplasms in body fluids based on correlation with clinical details, critical evaluation of cytology findings, and comparison with previous diagnosis along with the judicious use of ancillary techniques helps in deciding an early treatment plan.

Intra-Peritoneal Pseudocyst as a Rare Complication After Peritoneal Dialysis: The Use of a Staged Surgical Approach in Management

Despite its numerous benefits, peritoneal dialysis (PD) can rarely result in dangerous and even life-threatening complications, including peritonitis, hernias, encapsulating peritoneal sclerosis (EPS), and rarely peritoneal pseudocysts. Herein, we present a rare case of a giant intra-peritoneal pseudocyst that presented four months following the discontinuation of a 5-year course of complicated PD. Despite the initially successful drainages, the patient’s symptoms continued to recur, and the imaging findings were concerning for underlying neoplastic processes. As such, a staged surgical approach was performed, starting with a diagnostic laparoscopy and was subsequently followed with cyst excision and marsupialization to the peritoneal cavity. While previous reports of such rare pseudocyst have been documented in the literature as a complication of PD, to our knowledge, this is the second case of pseudocyst formation to occur months after the discontinuation of PD therapy. This case emphasizes the importance of close follow-up in PD patients and showcases how a staged surgical approach can be utilized to accurately diagnose and manage such complicated cases.

Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) in Physiological and Pathological Processes within the Gastrointestinal Tract: A Review

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide widely distributed in the central nervous system (CNS) and many peripheral organs, such as the digestive tract, endocrine, reproductive and respiratory systems, where it plays different regulatory functions and exerts a cytoprotective effect. The multifarious physiological effects of PACAP are mediated through binding to different G protein-coupled receptors, including PAC1 (PAC1-R), VPAC1 (VPAC1-R) and VPAC2 (VPAC2-R) receptors. In the gastrointestinal (GI) tract, PACAP plays an important regulatory function. PACAP stimulates the secretion of digestive juices and hormone release, regulates smooth muscle contraction, local blood flow, cell migration and proliferation. Additionally, there are many reports confirming the involvement of PACAP in pathological processes within the GI tract, including inflammatory states, neuronal injury, diabetes, intoxication and neoplastic processes. The purpose of this review is to summarize the distribution and pleiotropic action of PACAP in the control of GI tract function and its cytoprotective effect in the course of GI tract disorders.

The role of matrix metalloproteinases in pathogenesis of human bladder cancer

Matrix metalloproteinases (MMPs) play an important role in many physiological and pathological processes, including neoplastic processes. They belong to a group of enzymes called endopeptidases and have the ability to hydrolyze all proteins in the extracellular matrix (ECM). They are produced in most connective tissue cells, macrophages, leukocytes, endothelial cells, microglial cells and in cancer cells. Neoplastic diseases are one of the main causes of death in Poland and in the world, therefore learning about the process of carcinogenesis seems to be particularly important. The process of carcinogenesis is currently widely studied and MMPs play one of the key roles in the development of cancer. They do this by regulating local tumor growth, stromal invasion, stimulating angiogenesis and metastasis formation. Bladder cancer is the 7th most common cancer in the male population and the 11th most common cancer in the world. In bladder cancer, most studies have been devoted to MMP-2 and MMP-9, that are enzymes responsible for the degradation of type IV collagen in the first place, which through the destruction of basement membranes and ECM, play an essential role in the tumor invasion process. Since bladder cancer is characterized by the ability to relapse, from the point of view of clinical practice it seems particularly important to develop a marker of early bladder tumor recurrence. MMPs detected in the urine and serum of patients with bladder cancer are potential factors that could play such a role.

Impact of Estrogens Present in Environment on Health and Welfare of Animals

Nowadays, there is a growing interest in environmental pollution; however, knowledge about this aspect is growing at an insufficient pace. There are many potential sources of environmental contamination, including sex hormones—especially estrogens. The analyzed literature shows that estrone (E1), estradiol (E2), estriol (E3), and synthetic ethinyloestradiol (EE2) are the most significant in terms of environmental impact. Potential sources of contamination are, among others, livestock farms, slaughterhouses, and large urban agglomerations. Estrogens occurring in the environment can negatively affect the organisms, such as animals, through phenomena such as feminization, dysregulation of natural processes related to reproduction, lowering the physiological condition of the organisms, disturbances in the regulation of both proapoptotic and anti-apoptotic processes, and even the occurrence of neoplastic processes thus drastically decreasing animal welfare. Unfortunately, the amount of research conducted on the negative consequences of their impact on animal organisms is many times smaller than that of humans, despite the great richness and diversity of the fauna. Therefore, there is a need for further research to help fill the gaps in our knowledge.

Digital Lesions in Dogs: A Statistical Breed Analysis of 2912 Cases

Breed predispositions to canine digital neoplasms are well known. However, there is currently no statistical analysis identifying the least affected breeds. To this end, 2912 canine amputated digits submitted from 2014–2019 to the Laboklin GmbH & Co. KG for routine diagnostics were statistically analyzed. The study population consisted of 155 different breeds (most common: 634 Mongrels, 411 Schnauzers, 197 Labrador Retrievers, 93 Golden Retrievers). Non-neoplastic processes were present in 1246 (43%), tumor-like lesions in 138 (5%), and neoplasms in 1528 cases (52%). Benign tumors (n = 335) were characterized by 217 subungual keratoacanthomas, 36 histiocytomas, 35 plasmacytomas, 16 papillomas, 12 melanocytomas, 9 sebaceous gland tumors, 6 lipomas, and 4 bone tumors. Malignant neoplasms (n = 1193) included 758 squamous cell carcinomas (SCC), 196 malignant melanomas (MM), 76 soft tissue sarcomas, 52 mast cell tumors, 37 non-specified sarcomas, 29 anaplastic neoplasms, 24 carcinomas, 20 bone tumors, and 1 histiocytic sarcoma. Predisposed breeds for SCC included the Schnauzer (log OR = 2.61), Briard (log OR = 1.78), Rottweiler (log OR = 1.54), Poodle (log OR = 1.40), and Dachshund (log OR = 1.30). Jack Russell Terriers (log OR = −2.95) were significantly less affected by SCC than Mongrels. Acral MM were significantly more frequent in Rottweilers (log OR = 1.88) and Labrador Retrievers (log OR = 1.09). In contrast, Dachshunds (log OR = −2.17), Jack Russell Terriers (log OR = −1.88), and Rhodesian Ridgebacks (log OR = −1.88) were rarely affected. This contrasted with the well-known predisposition of Dachshunds and Rhodesian Ridgebacks to oral and cutaneous melanocytic neoplasms. Further studies are needed to explain the underlying reasons for breed predisposition or “resistance” to the development of specific acral tumors and/or other sites.

Identifying the deceiver: the non-neoplastic mimickers of genital system neoplasms

Tumors of the genital system are common and imaging is of crucial importance for their detection and diagnosis. Several non-neoplastic diseases may mimic these tumors and differential diagnosis may be difficult in certain cases. Misdiagnosing non-neoplastic diseases as tumor may prompt unnecessary medical treatment or surgical interventions. In this article, we aimed to present the imaging characteristics of non-neoplastic diseases of the male and female genital systems that may mimic neoplastic processes. Increasing awareness of the imaging specialists to these entities may have a severe positive impact on the management of these patients.