Surgical and Experimental Pathology

Molinari, Fábio Daniel

doi: 10.1186/s42047-025-00215-2pmid: N/A

BackgroundDigital pathology (DP) has progressed from early telepathology to integrated ecosystems that include whole‑slide imaging (WSI), archiving, collaboration, and computational analysis, with promised gains in workflow, remote consultation, and AI‑assisted diagnosis. In Latin America, adoption has lagged due to cost, connectivity, and integration barriers. Evidence specific to Brazil remains limited.MethodsWe conducted a descriptive pilot survey (17‑item Google Forms) disseminated via social media (WhatsApp, Instagram, LinkedIn) to practicing pathologists across Brazil (Oct–Nov 2023). The instrument was conceptually aligned with themes from the review “Digital Pathology in Latin America.” Responses were anonymous; only the region question was mandatory. Twenty-two respondents completed the survey (Southeast 22.7%, Northeast 22.7%, South 18.2%, North 18.2%, Center-West 18.2%).DiscussionIn Brazil, DP adoption remains limited despite optimism about near-term standardization. Cost is the primary barrier, followed by operational feasibility (infrastructure, training), mirroring the Latin-American landscape. To move from basic digitization to AI-enabled transformation, financial models, reimbursement, and market regulation must be addressed alongside technical integration and connectivity.

de Andrade Natal, Rodrigo; Araújo Jernigan, Ana Luiza; Oliveira Scliar, Marília de; Klock, Clovis; Távora, Fábio Rocha; Sousa, Juliana Cordeiro; Soares, Fernando Augusto; Macedo, Mariana Petaccia; Cunha, Isabela Werneck

doi: 10.1186/s42047-026-00216-9pmid: N/A

BackgroundLung adenocarcinoma frequently harbors activating EGFR variants, but their distribution may vary across Brazil due to regional demographic and ancestral differences. This study evaluated the frequency and subtype distribution of EGFR variants in three Brazilian regions and examined associations with clinicopathological features.MethodsA retrospective electronic search was performed to select patients with lung adenocarcinoma who underwent EGFR testing using a rapid RT–PCR platform across southeastern (SE), southern (S), and northeastern (NE) Brazil.ResultsEGFR variants were identified in 21% of all patients. Female patients had a higher frequency than males (p < 0.01), and the frequency varied significantly by region: 32% in the NE, 27% in the SE, and 11% in the S. The most common alterations were exon 19 deletion (45%) and p.Leu858Arg (43%). Variant subtype distribution also differed by region: the NE showed a disproportionately high frequency of exon 19 deletion, whereas the SE was the only region with p.Gly719Ala/Cys/Ser variants. Regional differences remained significant even after adjusting for gender (p < 0.01).ConclusionEGFR variant frequency and subtype distribution vary markedly across Brazilian regions, with the NE showing the highest overall mutation rate and the S the lowest. These patterns likely reflect underlying demographic, ancestral, and environmental differences and highlight the importance of regional molecular profiling to inform targeted therapy strategies and optimize resource allocation.

Rezaei, Reza; Sharbati, Fereshteh

doi: 10.1186/s42047-026-00239-2pmid: N/A

BackgroundRenal involvement is a frequent and often severe manifestation of systemic diseases, including autoimmune, metabolic, vascular, and hematologic conditions. The kidney’s unique vascular and structural features render it particularly vulnerable to systemic insults. Renal pathology not only reflects the nature of the underlying disorder but also plays a pivotal role in diagnosis, risk stratification, and therapeutic planning.ObjectiveThis narrative review provides a comprehensive overview of the major histopathological patterns encountered in systemic diseases affecting the kidney, highlighting the diagnostic utility of renal biopsy and ancillary studies, and addressing current diagnostic challenges.MethodsWe examined the renal pathological hallmarks of key systemic diseases, including lupus nephritis, ANCA-associated vasculitis, diabetic nephropathy, amyloidosis, and hypertensive nephrosclerosis. Diagnostic tools such as light microscopy, immunofluorescence, electron microscopy, and immunohistochemistry were reviewed in the context of their application to biopsy interpretation.ResultsWhile each disease exhibits characteristic morphologic features, overlapping patterns and nonspecific findings frequently complicate interpretation. Challenges such as masked immune deposits, limited sampling, and coexisting pathologies may lead to misclassification. Accurate diagnosis requires correlation with clinical, serologic, and imaging findings in a multidisciplinary context.ConclusionRenal biopsy remains the gold standard for evaluating systemic diseases with renal involvement. Integrating traditional histopathology with emerging technologies—such as digital image analysis, molecular typing, and AI-based pattern recognition—holds promise for improved classification, prognostication, and personalized patient care.

Danushka, P. G. N.; Jayasinghe, M. R.; Jeyaratnam, Y.; Biseka, A. G. D. S.; Aththanayaka, A. M.D. K.

doi: 10.1186/s42047-026-00240-9pmid: N/A

BackgroundFollicular variant of papillary thyroid carcinoma (FV-PTC) is a distinct subtype of thyroid cancer with intermediate clinical behavior between classical papillary and follicular carcinomas. While generally associated with favorable prognosis, FV-PTC can rarely present with distant metastases, including to the skull and scalp, posing diagnostic and therapeutic challenges.Case descriptionWe report a 51-year-old woman initially diagnosed with primary hypothyroidism and a thyroid goitre, later confirmed as FV-PTC after total thyroidectomy. Three years postoperatively, she developed a painless scalp lump. Magentic resonance imaging (MRI) revealed a large heterogeneously enhancing mass involving bilateral frontal skull bones with bone erosion and extension into scalp tissues, compressing adjacent brain structures without parenchymal invasion. Surgical excision of the scalp mass confirmed metastatic follicular thyroid carcinoma. The patient was managed with levothyroxine replacement and calcium supplementation after receiving radioiodine ablation therapy.ConclusionThis case highlights the importance of recognizing late solitary skull and scalp metastases in FV-PTC, which can lead to bone erosion and potential involvement of the brain parenchyma. The complementary use of MRI and computed tomography (CT) is vital for thorough assessment of both soft tissue and bony invasion. Given the risk of intracranial extension, management often requires a neurosurgical approach combined with reconstructive surgery to achieve effective tumor resection and restore structural integrity. Long-term surveillance and multidisciplinary treatment strategies remain essential to optimize outcomes in these complex and atypical metastatic presentations.

Cortes, Matias; Tarozzi, Ilaria; Reynolds, Meredith; Gitto, Lorenzo

doi: 10.1186/s42047-026-00245-4pmid: N/A

Pelvic inflammatory disease (PID) is an infection-induced inflammation of the upper female genital tract, which may involve the endometrium, fallopian tubes, ovaries, or pelvic peritoneum. Although Neisseria gonorrhoeae and Chlamydia trachomatis are well-established etiologic agents, anaerobic bacteria are increasingly recognized as significant contributors, particularly following intrauterine device (IUD) placement. Although best known as part of the oropharyngeal flora, Fusobacterium necrophorum also colonizes the gastrointestinal and female urogenital tracts and is a rare cause of PID. Its pathogenic potential outside the head and neck region is seldom reported, and fatal cases are exceptionally uncommon. In this case, a 46-year-old woman was found deceased at home approximately one month after IUD insertion. Postmortem examination revealed diffuse fibrinopurulent peritonitis, acute salpingitis, and a right ovarian cyst with surrounding inflammation. Cultures of peritoneal fluid and spleen were positive for F. necrophorum, confirming bacteremia. The cause of death was determined to be PID due to F. necrophorum infection. The IUD placement was considered a plausible contributing factor in the ascending infection. This case represents an exceedingly rare instance of fatal pelvic inflammatory disease caused by F. necrophorum. It highlights the importance of comprehensive microbiological investigations, integration of histopathological findings, and maintaining a broad differential diagnosis in forensic autopsy cases presenting with severe pelvic sepsis.

Akhtar, Mohtashim Idrees; Tazeen, Naushaba; Tabassum, Jasmine; Afroze, Idrees Akhtar

doi: 10.1186/s42047-026-00225-8pmid: N/A

BackgroundMale breast cancer (MBC) is a rare condition in the spectrum of breast cancer. It is most commonly diagnosed in men between the ages of 60 and 70, with an average age of 67 at diagnosis. MBC accounts for less than 1% of all breast cancer cases, with incidence varying across ethnic groups. Rates are highest among non-Hispanic Black men (1.89 per 100,000). Elevated incidence in South and Central Africa may be linked to hyperestrogenism from liver infections. Occult male breast cancer is extremely rare, accounting for only 0.3%–1% of all cases of breast cancer. Genetic predispositions, especially BRCA2 mutations, significantly increase the risk of MBC greater than BRCA1 mutations. The most frequent histological type is infiltrating ductal carcinoma, while invasive lobular carcinoma is exceptionally uncommon. MBC tumours are typically hormone receptor-positive. Key risk factors for MBC include older age, black ethnicity, genetic mutations, family history, liver cirrhosis, and testicular disorders. Most patients present with painless breast lumps, and about 50% have lymph node involvement at diagnosis.Case presentationA 61-year-old male presented with a 6-year history of non-tender swelling in the left axilla, with no associated systemic symptoms. Clinical examination revealed matted, erythematous lymph nodes, prompting fine needle aspiration and subsequent excision biopsy. Cytology demonstrated markedly atypical tumour cells with a high N: C ratio and significant pleomorphism. Histopathology of the lymph node confirmed effaced architecture with malignant cells arranged in sheets, cords, and cohesive tumour nests, along with capsular invasion. Immunohistochemistry showed CK7 and GATA3 positivity and strong HER2 (3+) expression, while ER, PR, Mammaglobin, and CK20 were negative—findings consistent with metastatic HER2-positive primary breast carcinoma. Positron emission tomography imaging revealed metabolically active axillary and deep pectoral nodes. The patient received neoadjuvant chemotherapy with docetaxel, carboplatin, trastuzumab, and filgrastim, followed by modified radical mastectomy with the breast parenchyma showing ypT0, ypN1a post 4 cycles of NACT.ConclusionThis case highlights the diagnostic challenges of male breast cancer, particularly when presenting solely as axillary lymphadenopathy. Immunohistochemistry and positron emission tomography play an essential role in establishing diagnosis and staging. Timely neoadjuvant chemotherapy and surgery achieved primary tumour clearance, underscoring the importance of early suspicion, comprehensive evaluation, and guideline-based management of HER2-positive MBC.

Rao, Shruti; Parikh, Rashmi Chintan; Jhirpe, Dinesh Kundalik; Kulkarni, Rahul Suhas; Dhake, Rahul Dnyandev

doi: 10.1186/s42047-026-00227-6pmid: N/A

Ewing Sarcoma is a common round cell sarcoma of pediatric patients arising in bone. Extraskeletal location is uncommon and small bowel wall is one of the rarer sites. Twenty-seven cases have been reported in published literature, exclusively arising from the small intestinal wall excluding the ones reported within the mesentery. We report a 45-year-old-man who presented with transient intussusception. After confirmation of a mass, right hemicolectomy was performed. The tumor identified in the ileum, infiltrated the wall through the submucosa, extending through muscularis propria into the subserosa. One of the regional nodes showed metastasis. On immunohistochemistry, the tumor cells were diffusely positive for CD99, CK 8/18 and NKX 2.2. The immunohistochemistry markers highlighted significant overlap between neuroendocrine neoplasm and Ewing Sarcoma. Molecular evaluation revealed the hallmark EWSR1-FLI1 fusion confirming the diagnosis. Extraskeletal Ewing Sarcoma of small intestines is rare and associated with overall poor prognosis. Immunohistochemistry shows considerable overlap with neuroendocrine carcinomas and molecular evaluation is prudent.

Palmal, Ruchira; Satarkar, Rahul; Yadav, Priyanka; Verma, Kartavya Kumar

doi: 10.1186/s42047-026-00217-8pmid: N/A

BackgroundPilocytic astrocytoma (PA) is the most commonly diagnosed primary brain tumor in children. The majority of documented astrocytic tumors are low-grade, with PA being the most prevalent. Pilomyxoid astrocytoma (PMA), a variant of PA, generally exhibits a more aggressive behavior compared to other variants. Due to its rarity and overlapping features with other entities in the literature, this case has been reported and discussed.Case presentation This report describes a case involving a 2-year-old boy presenting with a well-defined, lobulated lesion in the suprasellar region, alongside a review of relevant literature. During squash cytology from the frozen section, a low-grade tumor was identified, composed of cells with elongated, fibrillary cytoplasm and round to oval nuclei with dispersed chromatin. Histological examination confirmed the diagnosis, and we will provide a detailed account of the lesion’s histological and radiological features. Additionally, the report discusses the treatment options and the patient’s outcome.ConclusionThe diagnosis is challenging due to histological similarities to classic pilocytic astrocytoma, a difficulty often exacerbated by the limited tissue obtained from small biopsies in unresectable tumors. Squash cytology can only be used as a screening tool. Although classified as low-grade pediatric gliomas, PMA tends to be more aggressive than PA. Surgical resection remains the preferred treatment for effective disease management, although there is a risk of recurrence.

Gondim, Lívia Ribeiro; Nagel, Janaína; Sodré Dias Barreto, Patrícia; da Silva, Aline Lima; Sampaio Tomé Veloso-de-Araújo, Camila; Caldeira, Ana Cristina; Barros Figueiredo, Vinicius; Maíra Barros Luz , Débora; Paschoalini, Rafael Bispo; Watanabe, Isabela Conde; Dufloth, Rozany Mucha

doi: 10.1186/s42047-026-00234-7pmid: N/A

Artificial intelligence (AI) has already been studied not only in histological subtypes between benign and malignant tumors, but also for prognosis and prediction for therapeutic purposes, focusing on molecular alterations and assessment of the tumor microenvironment. This is a comprehensive review to address the current landscape of AI’s contribution in gynecological pathology to improve diagnostic accuracy, streamline analysis, and standardize histopathological evaluation. This review also provides evidence on the implementation of AI in this field of Pathology, with emphasis on three anatomopathological domains: endometrium, ovary, and cervix.

da Silva, Aline Lima; Nicolli, Ariadne Callegário; Araujo Junior, Mario Lucio Cordeiro; Costa, Luciana Carvalho

doi: 10.1186/s42047-026-00222-xpmid: N/A

Cervical cancer remains a major global public health problem, although it is largely preventable through vaccination against human papillomavirus and organized screening. Cervical cytology has historically been the primary method of screening, but this method has limitations related to its observer-dependent nature, intra- and inter-observer variability, and the diagnostic service burden. In this context, artificial intelligence has emerged as a promising tool to automate and standardize cytological analysis. The objective of this systematic review was to critically synthesize the available evidence on the application of artificial intelligence in cervical cytology, focusing on diagnostic performance, methodological limitations, and implications for screening programs. Search was conducted on the PubMed/MEDLINE base, resulting in the inclusion of 30 published studies in the last five years. Publications have predominantly analyzed deep learning algorithms, especially convolutional neural networks, applied to cytological classification according to the Bethesda System. In general, studies have shown high sensitivity and accuracy of AI-assisted cytology in the detection of squamous intraepithelial lesions and invasive carcinoma, often with comparable or superior performance to conventional cytological reading. However, specificity showed wide variation across studies, reflecting methodological heterogeneity, differences in datasets, and limitations related to external validation. Key constraints identified included the predominance of retrospective designs, the use of partial gold patterns, and challenges associated with scanning cytological samples. In summary, the application of artificial intelligence to cervical cytology shows significant potential to enhance the sensitivity, standardization, and efficiency of cervical cancer screening programs. However, its broad incorporation into clinical practice should occur in integration with human expertise and depends on the conduct of prospective, multi-center studies, with robust external validation and impact assessment in real-world scenarios.