Introduction. The pineal gland is a photo-neuro-endocrine organ situated inside the brain, that secretes serotonin, melatonin and N,N-dymethyltriptamine. This narrative review will address the latest information gathered on this function of the gland as well as the unknown roles it may have. The different histological and pathological findings of the pineal gland have demonstrated a role in clinical manifestations of numerous endocrine, neurological and psychiatric pathologies. Materials. For this narrative review we used the NCBI website database PubMed. The search terms were “Pineal Gland” AND/OR “histology, melatonin, DMT, pathology”. Total number of articles included were 86. Results: We have reviewed physiological information of melatonin and DMT, anatomical, histological and histopathological information on the pineal gland and its role in endocrine, neurological and psychiatric pathology. Conclusion. The role of melatonin in immunity and its potential therapeutic effects show promising potential for further research. DMT seems to have a role in psychiatric pathology and potential therapeutic effects. Proper tumoral screening and diagnostic protocol are required.

Hepatic stellate cell (HSC), initially analyzed by von Kupffer, in 1876, revealed to be an extraordinary mesenchymal cell, essential for both hepatocellular function and lesions, being the hallmark of hepatic fibrogenesis and carcinogenesis. Apart from their implications in hepatic injury, HSCs play a vital role in liver development and regeneration, xenobiotic response, intermediate metabolism, and regulation of immune response. In this review, we discuss the current state of knowledge regarding HSCs morphology, human HSCs markers and human HSC cell lines. We also summarize the latest findings concerning their roles in normal and liver pathology, focusing on their impact in fibrogenesis, chronic viral hepatitis and liver tumors.

The tumor microenvironment (TME), a complex assembly of cellular and extracellular matrix (ECM) components, plays a crucial role in driving tumor progression, shaping treatment responses, and influencing metastasis. This narrative review focuses on the cutaneous squamous cell carcinoma (cSCC) tumor stroma, highlighting its key constituents and their dynamic contributions. We examine how significant changes within the cSCC ECM—specifically, alterations in fibronectin, hyaluronic acid, laminins, proteoglycans, and collagens—promote cancer progression, metastasis, and drug resistance. The cellular composition of the cSCC TME is also explored, detailing the intricate interplay of cancer-associated fibroblasts (CAFs), mesenchymal stem cells (MSCs), endothelial cells, pericytes, adipocytes, and various immune cell populations. These diverse players modulate tumor development, angiogenesis, and immune responses. Finally, we emphasize the TME’s potential as a therapeutic target. Emerging strategies discussed in this review include harnessing the immune system (adoptive cell transfer, checkpoint blockade), hindering tumor angiogenesis, disrupting CAF activity, and manipulating ECM components. These approaches underscore the vital role that deciphering TME interactions plays in advancing cSCC therapy. Further research illuminating these complex relationships will uncover new avenues for developing more effective treatments for cSCC.

Background and objectives: The pineal gland is a photoneuroendocrine organ in the midline of the brain, responsible primarily for melatonin synthesis. It is composed mainly of pinealocytes and glial tissue. This study examined human postmortem pineal glands to microscopically assess age-related changes using digital techniques, and offers a perspective on evolutionary tendencies compared to the past. Materials and Methods: A retrospective autopsy study has been performed on 72 pediatric and adult autopsy cases. The glands have been processed for histological analysis and immunohistochemical staining with glial fibrillary acidic protein (GFAP). Slides were assessed under polarized light and digitally scanned. Morphometric data were obtained using CaseViewer and ImageJ. Results: Thirty-three females and 39 males were included in the study, grouped under three age groups: 0–25, 46–65, and 66–96 years of age. The peak gland volume was found within the 46–65 age group, the overall mean volume was 519 mm³, the main architectural types were lobular and insular, and the mean percentage of pineal calcification was 15% of the gland, peaking within the 66–96 age group, with a predominantly globular shape. Glial cysts were found in 20.8% of cases. The intensity of GFAP stain was maximal in the pediatric age group, but the extent of glial tissue was much larger in elderly patients. Discussion: The degenerative process of the pineal gland can be quantified by measuring normal parenchyma, calcifications, glial tissue, and glial cysts. Morphometric differences have been observed and compared to a similar studies performed in the published literature. The current study, unfortunately, lacks a 26–45 age group. Digital techniques seemed to offer a more exact analysis, but returned similar results to studies performed over 40 years ago, therefore offering important information on evolutionary tendencies. Conclusions: Increase in glial tissue, calcifications, and glial cysts have a defining role as age-related changes in the pineal gland.

COVID-19-associated rhino-orbital mucormycosis has become a new clinical entity. This study’s aim was to evaluate the histopathological and ultramicroscopic morphological aspects of this fungal infection. This was an observational retrospective study on eight patients from three tertiary centers in Romania. The tissue samples collected during functional endoscopic sinus surgery were studied through histopathological examination, scanning electron microscopy, and transmission electron microscopy. In the histopathological examination, the morphological aspects characteristic of mucormycosis in all cases were identified: wide aseptate hyphae with right-angle ramifications, which invade blood vessels. One case presented perineural invasion into the perineural lymphatics. And in another case, mucormycosis–aspergillosis fungal coinfection was identified. Through scanning electron microscopy, long hyphae on the surface of the mucosa surrounded by cells belonging to the local immune system were identified in all samples, and bacterial biofilms were identified in half of the samples. Through transmission electron microscopy, aseptate hyphae and bacterial elements were identified in the majority of the samples. Rhino-orbital-cerebral mucormycosis associated with COVID-19 produces nasal sinus dysbiosis, which favors the appearance of bacterial biofilms. The way in which the infection develops depends on the interaction of the fungi with cells of the immune system.