Sudden unexpected death in infancy (SUDI) remains a major challenge in pediatric pathology and forensic medicine. Despite advances in diagnostic techniques, many cases are still classified as unexplained and labeled as sudden infant death syndrome (SIDS). Increasing evidence suggests that a proportion of these deaths may be due to “hidden” causes not detectable through routine post-mortem examination. A narrative review of the literature (2000–2026) was conducted using PubMed and Scopus, focusing on under-recognized causes of SUDI and their diagnostic implications. Relevant studies were selected and organized into major pathological and forensic categories. Hidden causes of SUDI include a wide spectrum of conditions. Cardiac disorders—such as myocarditis, cardiomyopathies, and inherited arrhythmogenic syndromes—are frequently implicated and may require molecular autopsy for detection. Infectious diseases, often presenting with minimal or nonspecific findings, represent another important category, particularly viral and bacterial infections. Inborn errors of metabolism, especially fatty acid oxidation defects, may lead to sudden death in the absence of specific autopsy findings, highlighting the role of biochemical analyses. Neuropathological abnormalities involving brainstem regulatory systems may contribute to impaired autonomic control. Environmental, toxicological, and medico-legal factors—including unsafe sleep conditions, toxic exposures, and inflicted injury—must also be considered. SUDI is a multifactorial entity in which many unexplained deaths may be attributable to identifiable but overlooked conditions. A standardized, multidisciplinary approach integrating autopsy, ancillary investigations, and molecular diagnostics is essential to improve diagnostic accuracy and support prevention strategies.

Panton-Valentine leukocidin (PVL)-producing Staphylococcus aureus is associated with highly aggressive necrotizing pneumonia characterized by rapid clinical deterioration and high mortality. However, the clinicopathological features of fatal cases, particularly in the forensic setting, remain incompletely defined. We report a fatal case of PVL-positive S. aureus necrotizing pneumonia diagnosed through forensic autopsy and molecular analysis. In addition, a systematic review was conducted according to PRISMA 2020 guidelines. PubMed/MEDLINE and Scopus were searched from database inception to 12 March 2026 to identify published fatal cases of PVL-positive S. aureus pneumonia. A previously healthy 58-year-old man presented with acute respiratory symptoms and rapidly developed severe respiratory failure and septic shock, resulting in death within 24 h of hospital admission. Blood cultures and bronchoalveolar lavage yielded methicillin-susceptible S. aureus. Autopsy revealed bilateral necrotizing hemorrhagic bronchopneumonia, and molecular analysis confirmed PVL positivity. The literature review identified 31 fatal cases. Most cases were characterized by rapid clinical deterioration, frequent septic shock, and hemoptysis or pulmonary hemorrhage. When autopsy was performed, a consistent pattern of necrotizing and hemorrhagic pulmonary infection was observed. PVL-positive S. aureus pneumonia represents a rare but highly aggressive infection that may rapidly progress to respiratory failure and death. The combination of rapid clinical deterioration, hemoptysis, and necrotizing hemorrhagic pneumonia at autopsy represents a distinctive clinicopathological pattern. Integration of autopsy findings with microbiological and molecular investigations is essential for establishing the diagnosis in rapidly fatal infectious deaths.

Waterhouse–Friderichsen syndrome (WFS) represents a fulminant septic condition characterized by bilateral adrenal hemorrhage and rapid clinical deterioration. Although classically associated with meningococcal infection, fatal cases occur across multiple infectious etiologies and heterogeneous clinical contexts. In forensic practice, diagnosis frequently relies on post-mortem interpretation rather than clinical recognition, making consistent pathological assessment essential. A systematic review was conducted according to PRISMA guidelines to identify autopsy-confirmed fatal cases consistent with WFS. PubMed/MEDLINE and Scopus were searched from database inception to 21 February 2026, with a supplementary search conducted in Google Scholar. Eligible studies included fatal human cases with bilateral adrenal hemorrhage documented at autopsy and sufficient pathological and/or microbiological data. Data were extracted on clinical course, gross and histopathological findings, microbiological investigations, pathogens, and predisposing factors. Owing to marked heterogeneity of case-level reporting, qualitative synthesis and semi-quantitative descriptive analysis were performed. Sixty-five studies, encompassing 86 individual fatal cases, met the inclusion criteria. Bilateral adrenal hemorrhage consistently occurred within a broader systemic septic pattern characterized by multiorgan congestion, hemorrhagic manifestations, and variable disseminated intravascular coagulation-related changes. Histopathological and microbiological findings were heterogeneous, with frequent discrepancies between culture-based and molecular results and recurrent diagnostic limitations related to post-mortem microbiology. The synthesis of evidence supports interpreting WFS as a recurrent forensic-pathological pattern rather than a single morphological diagnosis. Based on key findings identified across cases, practical forensic frameworks were developed to support autopsy interpretation, microbiological sampling, and differential diagnosis. Integration of morphology, histopathology, microbiology, and circumstantial data may improve consistency and reproducibility in the medico-legal evaluation of sudden septic deaths.

Background: Cysticercosis is caused by the larval stages of Taenia and Versteria species. While Taenia solium , associated with a domestic life cycle, is the primary etiological agent of human (neuro)cysticercosis worldwide, sporadic cases involving Taenia species linked to wildlife have also been reported. A 72‑year‑old immunocompetent woman presented in October 2024 to the Emergency Department with paresthesia, gait imbalance, and severe headache. Neuroimaging revealed a <1‑cm edematous lesion in the frontal cortex, suspicious for metastasis. Surgical removal was performed. Histopathological examination showed necrotic tissue with abundant inflammatory infiltrate, ruling out neoplasia and raising suspicion of an infectious etiology. She was discharged in February 2025 with improved symptoms. Ongoing follow-up demonstrated progressive improvement leading to complete remission. Methods: Serological tests, coproparasitological examinations, and panfungal PCR targeting the 18S rRNA gene were performed. Intraoperative material, including formalin-fixed paraffin-embedded (FFPE) tissue samples, was collected and processed for histological, immunohistochemical, and molecular analyses. Histological sections were stained with hematoxylin and eosin (H&E) and Periodic acid–Schiff (PAS). Immunohistochemical analyses were carried out on FFPE sections to investigate infection with Echinococcus spp. For molecular analysis, genomic DNA was extracted from FFPE tissue using a dedicated commercial kit, following the manufacturer’s instructions. Mitochondrial gene targets ( cox1, nad1, and 12S rRNA) were amplified by PCR and subsequently sequenced. Results: Serological tests, coproparasitological examinations, and panfungal PCR targeting the 18S rRNA gene were negative. Histological analysis showed an inflammatory lesion with a necrotic core, while immunohistochemical analyses were negative for Echinococcus spp. Molecular analysis was positive, and sequence and phylogenetic analyses identified the cestode Taenia martis . Conclusions: This finding underscores the need for clinicians to consider less common Taenia species as potential causes of cysticercosis and neurocysticercosis, particularly when serological tests are negative or inconclusive despite a clinically suggestive presentation. Graphical