Circulating plasmablasts and plasma cells are characteristic but underrecognized features of acute dengue virus (DENV) infection because of their transient nature. Their presence on peripheral blood smears may erroneously suggest a plasma cell dyscrasia.

We report a case of secondary acute DENV serotype 3 infection in a 57-year-old traveler returning from the Caribbean that had morphologically suspected circulating plasma cells and thrombocytopenia, documented by peripheral blood smear and serial hematology analyzer scattergrams. Immunophenotypic confirmation was unavailable. We also performed a narrative review of published reports of plasmablast/plasma cell kinetics in DENV.

An abnormal reactive lymphocyte scattergram with an increased very high-fluorescence cell signal prompted smear review, which revealed the abrupt appearance of reactive (activated) lymphocytes (25%) and suspected plasma cells (5%) on day 6 after symptom onset, coinciding with the platelet nadir, despite clinical improvement. Published reports have described circulating plasmablasts/plasma cells from day 2, peaking around day 6, and disappearing by day 12, mirroring thrombocytopenia.

Increased very high-fluorescence cell signal on the lymphocyte scattergram should prompt peripheral blood smear review to assess suspected plasmacytosis because high-fluorescence gating, although sensitive, is not definitive. In the appropriate context, circulating plasma cells with thrombocytopenia should raise suspicion of DENV rather than a plasma cell neoplasm. These cells' kinetics may represent a potential adjunctive, phase-related laboratory clue that requires prospective validation.

Head and neck squamous cell carcinomas (HNSCCs) remain a significant clinical challenge due to treatment resistance and therapy-associated toxicity. Here, we evaluate the therapeutic potential and mechanism of action of AOH1996, a first-in-class small molecule that targets a cancer-associated isoform of proliferating cell nuclear antigen (caPCNA). Across HPV-positive and HPV-negative HNSCC models, AOH1996 induces robust cytotoxicity associated with mitotic arrest, multipolar mitosis, failed cytokinesis, cell-cell fusion, and DNA damage. Live-cell imaging reveals widespread mitotic catastrophe with limited successful mitotic progression. Notably, AOH1996 sensitivity correlates with c-Myc abundance, suggesting a potential biomarker of response. In vivo, AOH1996 suppresses tumor growth with minimal toxicity in xenograft models. Together, these findings establish AOH1996 as a promising therapeutic candidate that disrupts mitotic fidelity and induces cancer-selective cytotoxicity in HNSCC.

To determine whether prototype integrated slice-specific shimming (iShim) diffusion-weighted imaging (DWI) combined with Boost diffusion sampling improves image quality and diagnostic performance for focal liver lesions compared with conventional DWI and alternative iShim sampling schemes.

Eighty-five patients with focal liver lesions underwent 3T MRI with conventional DWI and iShim-DWI using Boost, flow-compensated (FC), monopolar (Mono), FC with five lobes (FC5), and stimulated echo acquisition mode (Steam) sampling at b-values of 0 and 1000 s/mm². Two radiologists independently scored six image-quality features. Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and apparent diffusion coefficient (ADC) were measured. Interreader agreement, between-sequence differences, ADC correlations and agreement, and diagnostic performance for differentiating benign from malignant lesions were assessed.

Boost iShim-DWI yielded significantly better artifact, diagnostic-confidence, and total-image-quality scores than all other sequences (p < 0.05) and achieved the highest lesion SNR, liver SNR, and CNR (p < 0.05). Interreader agreement was excellent (ICC = 0.839-0.953). ADC values correlated strongly across sequences (rₛ = 0.812-0.961, p < 0.001). Boost iShim-DWI achieved the highest diagnostic performance (AUC = 0.942; 95% CI 0.897-0.988). Discussion: Boost iShim-DWI improves liver DWI image quality while preserving ADC comparability and may enhance differentiation of benign and malignant focal liver lesions.

Gastrointestinal stromal tumors (GISTs), the most common mesenchymal neoplasms of the gastrointestinal tract, are molecularly heterogeneous diseases rather than a single entity. Activating mutations in KIT and PDGFRA define the dominant biological dependencies and establish tyrosine kinase inhibition as a therapeutic backbone. Imatinib, followed by later-line tyrosine kinase inhibitors, including sunitinib, regorafenib, ripretinib, and genotype-selected avapritinib, have substantially prolonged survival. However, durable disease control remains limited by clonal evolution, most notably, polyclonal secondary KIT mutations and lesion-to-lesion molecular heterogeneity. Molecular profiling using serial tissue and circulating tumor DNA analyses may improve precision care by identifying spatially and temporally evolving resistance mechanisms and guiding mutation-matched treatment selection. In this review, we summarize the biological and molecular landscape of advanced GIST, as well as the current therapeutic strategies and major mechanisms of resistance. Finally, we highlight promising therapeutic strategies supported by preclinical and clinical evidence that may advance subtype-informed precision medicine.

NTRK-rearranged spindle cell neoplasm is a rare lesion in the uterus (including the cervix), with more than 60 tumors reported in the literature so far. Most of them are characterized by fascicles of spindle cells in herringbone pattern with entrapment of endocervical glands. We report an additional tumor occurring in the uterine cervix of a 43-year-old Chinese woman, which demonstrated unusual morphologic features in addition to the conventional fibrosarcoma-like spindle cell proliferation. These included areas of neural-like whorls, as well as nuclear palisading that resembled a schwannoma. Focal myxoid stroma with loose clusters of rhabdoid cells was also identified. The nuclear grade was intermediate to severe and geographic necrosis was identified. Immunohistochemistry showed diffuse positivity for pan-TRK with patchy CD34 and focal S100 expression. Molecular analysis revealed the presence of TPM3::NTRK1 fusion with CDKN2A/B homozygous deletion and low mutational burden. Our case report and literature review highlight the diverse morphological appearance of this tumor. Specifically, nuclear palisading and rhabdoid cells are rarely reported in uterine NTRK-rearranged spindle cell neoplasm. As more clinical and molecular data become available, the clinicopathological features of this entity can be further characterized.

Primary large cell neuroendocrine carcinoma (LCNEC) of the bladder is an extremely rare and highly aggressive malignancy with a poor prognosis, bringing major challenges to clinical diagnosis and treatment. We report the case of a 77-year-old man who presented with recurrent gross hematuria for more than 8 months, accompanied by urinary frequency, urinary urgency, and lumbosacral pain. Imaging revealed a large soft-tissue mass on the posterior bladder wall without pathognomonic imaging findings. Urine exfoliative cytology revealed atypical tumor cells with large cellular size, high nucleocytoplasmic ratio, scant cytoplasm, and marked nuclear atypia. Given the advanced age and multiple underlying comorbidities, the patient underwent transurethral resection of the bladder tumor. Histopathologically, the tumor was arranged in diffuse sheets with organoid architecture, composed of large polygonal cells with prominent atypia, active mitosis, focal necrosis, and intravascular tumor thrombi. Immunohistochemically, CK-Pan showed a paranuclear punctate expression pattern; neuroendocrine markers INSM1, Syn, and CD56 were diffusely positive; Ki-67 showed a high proliferation index; and P53 displayed diffuse strong expression. The final diagnosis of primary bladder LCNEC was confirmed by integrated morphological and immunohistochemical findings, with preoperative contrast-enhanced CT defining an advanced clinical stage of cT3N0M0 (American Joint Committee on Cancer, AJCC 8th edition). The patient received postoperative adjuvant chemotherapy, and tumor recurrence was identified at the 3-month follow-up with a stable general condition during the observational period. This case indicates that bladder LCNEC lacks specific clinical and imaging manifestations. Urine exfoliative cytology is a valuable non-invasive ancillary tool for detecting high-grade malignant cells in the urinary tract, whereas combining histopathology and immunohistochemistry remains the gold standard for definitive diagnosis. Surgical resection combined with individualized chemotherapy constitutes the main therapeutic regimen, and close long-term follow-up is indispensable for this highly aggressive tumor. Further clinical studies are required to optimize therapeutic strategies and improve patient prognosis.

Globally, colon cancer remains one of the leading causes of mortality. Multidrug resistance, systemic toxicity, and poor tumor selectivity significantly limit conventional chemotherapy. This review highlights the need for localized therapy to increase efficacy and minimize systemic side effects. Colon-targeted drug delivery systems (CDDS) are designed and developed to overcome these challenges. Both natural and synthetic polysaccharides act as carriers in CDDS because of their biodegradability, biocompatibility, pH- and enzyme-responsiveness, and mucoadhesive properties. Polysaccharides such as chitosan, dextran, pectin, alginate, and hyaluronic acid have been formulated into nanoparticles, microparticles, and hydrogels, enabling controlled and site-specific delivery. These carriers deliver chemotherapeutics, nucleic acids, and immunotherapeutics, as well as theranostic agents that combine imaging and therapy. Preclinical evidence demonstrates significant translational potential for polysaccharide-based CDDS. However, clinical trials remain limited, which highlights the gap between laboratory findings and clinical applications. Major challenges in colon-targeted drug delivery include variability in polysaccharide sources and quality, difficulties in large-scale manufacturing, and regulatory challenges. Addressing these challenges will be essential to move towards commercialization and clinical adoption. Personalized therapy through microbiome profiling, integration with nanotechnology and bioinformatics, and smart, biosensor-responsive carriers will be the focus going forward. Polysaccharide-based CDDS provide safer, more effective, and more personalized treatment with continued research to optimize delivery and overcome existing limitations.

Collision tumours are uncommon lesions in which two histologically distinct neoplasms coexist at one anatomical site, creating diagnostic difficulty when one component predominates clinically or histologically. A 70-year-old man presented with a large exophytic pigmented tumour on the lower abdomen that had been present for approximately 20 years and had enlarged rapidly during the preceding 5 years. He was brought to the emergency department because of tumour bleeding, progressive anaemia, poor nutritional status, and difficulty with mobilisation. Contrast-enhanced computed tomography during emergency systemic assessment revealed multiple pulmonary, hepatic, and bilateral lymph node lesions suspicious for distant metastases. Because urgent local control was required, no preoperative incisional biopsy was performed, and complete excision with immediate reconstruction was undertaken as a therapeutic excisional biopsy. Initial histopathological and immunohistochemical evaluation showed basal cell carcinoma with BerEP4 positivity. However, the metastatic pattern was inconsistent with basal cell carcinoma, prompting biopsy of a pulmonary nodule, which demonstrated malignant melanoma. Because primary pulmonary melanoma is extremely rare, the abdominal lesion was re-evaluated. Additional sampling from previously unsampled areas identified a MelanA-positive atypical melanocytic component adjacent to and partially intermingled with the basal cell carcinoma, confirming a cutaneous collision tumour. The distant lesions were interpreted as metastases from the melanoma component. BRAF V600 mutation analysis was negative, and nivolumab plus ipilimumab was initiated. However, the disease progressed rapidly, further systemic therapy was discontinued, and the patient died shortly thereafter from cancer-related complications. This case highlights how sampling bias and clinicopathological discordance can obscure aggressive malignant components in cutaneous collision tumours. In large, heterogeneous, or clinically aggressive cutaneous tumours, systematic multi-site sampling and prompt clinicopathological reassessment are essential when the initial pathological diagnosis does not fully explain the clinical behaviour.

Retinoblastoma (RB) is a treatable tumor that arises in the retina, mainly affecting children under 2 years old. It results from a mutation on the long arm of chromosome 13, specifically of the RB1 gene (13q14). Patients with the hereditary form of RB have a higher incidence of metastases and secondary cancer development. These cancers, including metastasis, secondary malignant neoplasms, and radiation-associated sarcomas, are rare and typically occur in advanced stages. Although the overall prognosis for RB is generally favorable, it declines significantly when metastases develop. While rare, the most common sites of RB metastasis are the brain, osseous structures, cervical nodes, central nervous system, lungs, and liver. Here, we present the clinical and radiologic features of three patients with osseous metastasis from RB and review current literature, including the development of secondary malignant neoplasms, radiation-associated sarcomas, prognosis, and treatment options.

 Small intestinal cavernous hemangiomas are rare vascular malformations that present diagnostic and therapeutic challenges due to their deep location and propensity for recurrent bleeding. This report aims to describe a case with a sequential management approach and to synthesize existing evidence through a narrative literature review.

A 74-year-old female presented with recurrent melena for five months. Initial imaging (gastroscopy, colonoscopy, computed tomography angiography, and computed tomography enterography) revealed no bleeding source. Balloon-assisted enteroscopy identified a 0.6 cm mucosal protrusion 520 cm distal to the pylorus, with active oozing. Endoscopic hemostasis was achieved using metal clip occlusion and lauromacrogol sclerotherapy, following which a biopsy was performed safely to confirm the diagnosis of hemangioma. Six months later, melena recurred, and the patient underwent surgical resection of the same lesion. Pathological examination confirmed a cavernous hemangioma. At two-year follow-up, the patient remained free from recurrent gastrointestinal bleeding.

 This case highlights the value of balloon-assisted enteroscopy for localizing obscure small intestinal bleeding and achieving temporary hemostasis. While endoscopic intervention facilitates diagnosis and acute bleeding control, surgical resection remains the definitive treatment for selected cases. Close follow-up may be considered to monitor for potential recurrence. A narrative review of the literature supports the rarity of this condition and the limited evidence base for treatment standardization.