High Mitotic Activity Research Articles

Large-cell Basaloid Adenocarcinoma of the Lung: A Clinicopathologic Study of 12 Cases of a Distinctive Form of Lung Cancer Often Mistaken for Large-cell Neuroendocrine Carcinoma.

A distinctive form of lung adenocarcinoma that closely mimics large-cell neuroendocrine carcinoma is described. The tumors arose in 6 women and 6 men aged 46-86 years (mean=58.4). They presented as peripheral subpleural masses measuring 2-12cm (mean=6.5cm). Histologically they were characterized by islands or anastomosing and serpiginous strands of large, atypical cells showing striking peripheral palisading of nuclei, with high mitotic activity and prominent comedo-like areas of necrosis. Because of the striking resemblance to neuroendocrine tumors, some of the cases were initially diagnosed as large-cell neuroendocrine carcinoma despite the absence of neuroendocrine markers. Immunohistochemistry showed positivity of the tumor cells for TTF1 and napsin-A, and negative staining for p40. The tumors were also uniformly negative for multiple neuroendocrine markers, including chromogranin, synaptophysin, CD56, and INSM1. Electron microscopy performed in 2 cases was negative for membrane-bound dense core neurosecretory granules. Pathogenic alterations were detected in 5 of 8 tumors tested by next-generation sequencing. Point mutations in KRAS and TP53 were identified in 5 patients. Low-level amplification of GNAS, KIT, and FGFR1 was present in 2 patients. No RB1 mutations were identified. Clinical follow-up in 10 cases showed that 2 patients died of their tumors, 2 experienced distant metastases, and 6 were alive and well from 1 to 13 years after diagnosis (median=7.1y). Large-cell basaloid adenocarcinoma is an unusual variant of lung cancer that is easily confused with large-cell neuroendocrine carcinoma. Awareness of this unusual variant of lung adenocarcinoma is important for treatment and prognosis and for avoiding misdiagnosis.

Rare Presentation of Anaplastic Carcinoma as a Mural Nodule in Mucinous Cystadenoma with Concurrent Benign Brenner Tumor

Abstract Introduction/Objective Mural nodules in ovarian mucinous tumors, particularly which are anaplastic carcinomas, represent an exceedingly rare and complex diagnostic category. The literature documents only a few such tumors, predominantly sarcoma-like, with favorable prognoses. In contrast, malignant mural nodules, including anaplastic carcinoma and sarcomatous or carcinosarcomatous types, are notably rare, with fewer than ten cases reported. The co-occurrence of an anaplastic carcinoma mural nodule with a benign Brenner tumor presents distinct diagnostic and treatment complexities stemming from mixed tumor pathology and associated genetic mutations like KRAS and p53, critical in the development of these unusual nodules. This report deepens our insight into rare ovarian tumors. Methods/Case Report A 60-year-old woman with persistent lower abdominal pain underwent surgery for a suspected benign ovarian cyst based on initial imaging. The removed ovary contained a 10.5 x 10 x 8 cm unilocular cyst lined with benign, mucin-containing columnar epithelium. However, a 2 cm anaplastic carcinoma mural nodule was identified within the cyst, exhibiting cellular pleomorphism, nuclear atypia, and high mitotic activity. Immunohistochemical staining confirmed the carcinoma with diffuse cytokeratin and EMA positivity. The fallopian tube was free of tumor involvement, and no capsular or lymphovascular invasion was seen. The cancer was staged as PT1a, pNx, pMx. Results (if a Case Study enter NA) NA Conclusion Anaplastic carcinoma, when present as a mural nodule within a benign-looking mucinous cystadenoma, demands an aggressive treatment strategy due to its poor prognosis and aggressive nature. Such cases require a deviation from standard benign treatment protocols to include extensive surgery, possibly, depending on disease progression, chemotherapy or radiation.

DICER1 Mutations Enable Rare Tumor Formation

Abstract Introduction/Objective DICER1 is a tumor suppressor gene that imparts a slight increase in tumor formation when mutated. The protein plays a role in processing miRNA that silences transcription. Germline mutations of DICER1 predispose to tumors in a known set of organs and rarely in other locations. However the presence of additional genetic aberrations further increases the likelihood of tumor formation. Acting as a compounding factor, DICER1 mutations can present a constantly shifting cancer phenotype of affected patients. Of particular interest here is the development of both Pineoblastoma and Malignant spindle cell sarcoma in a young patient. Sarcomas are estimated to make up only 10% of pediatric cancers and Pineal masses only 3%. Methods/Case Report This case involves an 8 year old male with a history of Pineoblastoma who originally presented with slowly worsening ataxia. A screening ultrasound on following visits identified an abdominal mass that was confirmed with computed tomography. Subsequent biopsies showed malignant spindle cells arranged in a herringbone pattern. Additionally these cells displayed high mitotic activity and hyperchromatic nuclei. Surprisingly, they also demonstrated extramedullary hematopoiesis. Multiple stains were performed however no significant conclusion could be made. The appearance of this tumor and its rarity prompted a request for a Complete Comprehensive Sarcoma Panel via Next Generation Sequencing. This confirmed the presence of pathologic BRAF and DICER1 genes. From that the diagnosis of DICER1 associated Malignant Spindle Cell Sarcoma was made. BRAF V600E is the most common genetic variant and is seen in multiple cancers but only seen in 1-3% of sarcomas. Pathologic variants of the DICER1 gene exist on exons 13 and 25. The presence of these exon mutations in some way affect DICER1 protein function and compound the effects of the mutated BRAF gene. This situation is unique as such neoplasms are rarely found in the anterior abdominal wall and showcases the effects of DICER1 on rare tumor phenotypes. Results (if a Case Study enter NA) NA Conclusion Continuing research into both DICER1 protein pathways is essential for isolating a diagnosis and guiding treatment. It would seem screening images and genetic testing would benefit pediatric or even adult patients with common and rare cancers. Extra effort made toward this would not be outside the norm as personalized medicine is gradually becoming the standard for cancer treatment.

Early Genetic Divergence of High-Grade Carcinomas Originating from Low-Grade Serous Ovarian Neoplasms

The current paradigm implicates a fallopian tube precursor as the origin of most ovarian high-grade serous carcinomas (HGSCs). However, a rare subset of HGSCs develop via a distinct pathway from low-grade serous ovarian neoplasms (namely, serous borderline tumors and low-grade serous carcinoma). This alternate pathway for the development of HGSC and other poorly differentiated carcinomas of the ovary is not well understood. To elucidate the molecular pathogenesis and evolutionary trajectory of histologic transformation of low-grade serous neoplasms, we performed whole exome sequencing on microdissected low-grade and higher-grade components from 7 cases of serous borderline tumor or low-grade serous carcinoma associated with a synchronous or metachronous indeterminate/high-grade carcinoma. In most cases, there were relatively few somatic mutations shared between matched low-grade and higher-grade tumors compared with private mutations specific to each component (ie, phylogenetic trees with short trunks and long branches). Truncal mutations, present across all tumor samples from a given patient, included known drivers of low-grade serous neoplasms: KRAS (G12D, n = 4), BRAF (G469A, n = 1), NF2 (n = 1), and USP9X (n = 1). Transformation to HGSC was associated with a TP53 mutation with bi-allelic inactivation in 3 cases, all with severe nuclear atypia, and associated with genome-wide copy number alterations and allelic imbalances. TP53-wildtype tumors comprised a morphologic spectrum, which included indeterminate-grade serous carcinomas with moderate nuclear atypia and high mitotic activity, although lacking extensive chromosomal instability (n = 2) and poorly differentiated carcinomas (n = 2, including a high-grade Mullerian carcinoma and an undifferentiated carcinoma with sarcomatoid features). In summary, synchronous and metachronous low-grade serous neoplasms and higher-grade carcinomas are clonally related. Early genetic divergence, most evident in cases with TP53 mutations, suggests that high-grade transformation may be a relatively early molecular event.

6955 A Rare Case of Rapidly Enlarging High Grade Follicular-Derived Carcinoma in a Young Patient - Formerly Known as Insular Thyroid Carcinoma with good response to Radioactive iodine ablation- A New Name, Same Aggressive Features

Abstract Disclosure: R. Abdelmasih: None. N. Prasad: None. N. Shah: None. Introduction: Follicular-derived thyroid carcinomas, formerly known as insular thyroid carcinomas, are an albeit rare but highly lethal thyroid carcinoma subtype with an incidence of 1-10% worldwide. It is known for its aggressive nature and comprises the majority of deaths from non-anaplastic follicular thyroid cancers. Case Presentation: A 30-year-old male presented with 2-year history of progressively enlarging painless right neck mass. Physical exam revealed 6x3 cm right well-circumscribed mobile mass not displacing the trachea. Head and neck CT showed 6.5 cm right thyroid mass with level 2A lymph node. Neck Ultrasound showed a 6.4 cm right thyroid nodule. Fine needle aspiration of the mass showed atypia of undetermined significance. Patient returned to clinic 1 year later with progressively enlarging right neck mass, now associated with dysphagia measuring 10 cm in physical exam deviating the trachea to the left. Repeat CT H&N showed 10 cm right thyroid mass with moderate tracheal deviation and US showed 11 cm right heterogenous thyroid mass with regular margins and negative LNs. Patient underwent right thyroid lobectomy with surgical pathology showed 11.4 cm tumor with vascular invasion and no extrathyroidal extension. Pathology showed high grade follicular-derived Thyroid Carcinoma. Patient underwent completion thyroidectomy with benign pathology followed by radioactive iodine ablation 107.8 mCi I131 with successful targeting of residual thyroid tissue and no evidence of iodine avid distant metastasis. Patient has been followed closely for 2 years now with regular US, thyroglobulin level with recurrence. Discussion: Insular thyroid carcinomas are aggressive malignancies predominantly seen in females within the age of 55-65 though cases of young patients and children have been reported. Patients often present with enlarging goiter, dysphagia, and dyspnea however, metastatic disease to lymph nodes, lung and bone has also been reported as primary presentation in 20% of cases. Per literature review, recurrence and mortality rates have very wide range of 36-83% and 9-75% respectively which could be explained by a variety of prognostic factors including Patient age, tumor size, Macroscopic evident extrathyroidal extension, distant metastasis, or tumor necrosis. Often times insular thyroid carcinomas are mistaken for anaplastic carcinoma and thus fine needle aspiration is a helpful diagnostic tool to differentiate insular carcinoma. Pathology typically demonstrates well-defined insulae of thyroglobulin-filled follicles, necrotic foci, and high random mitotic activity. Treatment includes total thyroidectomy followed by high-dose radiotherapy. We Present this case to shed light on such a rare aggressive entity that requires early detection, belligerent management, and close follow-up for promising outcomes. Presentation: 6/3/2024

Metastatic prostate adenocarcinoma to the brain – a clinicopathologic analysis of 21 cases

BackgroundBrain metastasis from prostate adenocarcinoma (PCa) is rare, often leading to death within a year. Its infrequent occurrence and atypical histopathologic features contribute to lower consideration in the differential diagnosis of tumor brain metastasis. This study aims to assess the clinical characteristics and distinctive histopathologic features of metastatic PCa in the brain for timely and enhanced diagnostic accuracy.DesignA retrospective search spanning 20 years (2003–2022) was conducted on our archives and identified 21 cases diagnosed as “metastatic prostate adenocarcinoma (mPCa)” in brain biopsies and resections. All existing slides were thoroughly reviewed to evaluate the histopathology of the mPCa.ResultThe mean age at presentation for brain metastasis was 70 years. Of 21 cases, 5 were dural-based lesions, 16 were true intraparenchymal metastases, including 2 sellar/suprasellar masses, 3 frontal, 3 temporal, 3 occipital, 1 cerebellum, and 4 involving multiple brain lobes. The average interval between initial diagnosis and brain metastasis was 90.75 months. Notably, brain metastasis was the initial presentation for one patient, while another patient, initially diagnosed with prognostic grade group (GG) 2 PCa in 1/12 cores, presented with isolated brain metastasis two years later. Architecturally, tumor cells were arranged in sheets or nests in most cases; however, four cases showed histologic cribriform patterns, and five displayed papillary architecture. Cytohistology varied from uniform monomorphic to highly pleomorphic cells with prominent nucleoli (8/19) and high mitotic activity. Interestingly, 1 case showed small round blue cell morphology, another had focal areas of rhabdoid and spindle cell differentiation, and 6 had cytoplasmic clearing. Almost half of the cases (47%) showed necrosis.ConclusionmPCa to the brain can present with variable histomorphology. Therefore, consideration of mPCa in the differential diagnosis of metastatic brain lesions, even with non-suggestive imaging, is imperative in male patients with or without a history of primary disease. Accurate and prompt diagnosis is crucial, given the recent advancements in treatment that have improved survival rates.

A Rapidly Growing Nodule on the Eyebrow of a Pediatric Patient

A 11-year-old Caucasian girl presented to our Dermatology Unit with a 2-month history of an erythematous nodule, localized to the medial portion of her left eyebrow, rapidly growing in the two weeks before presentation. The histopathological examination revealed a dermal multi-nodular epithelial neoplasm composed of clear cells, squamous cells, and glandular cells, characterized by cytologic atypia, high mitotic activity, and an infiltrative deep growth pattern. The immunohistochemical profile of the lesion was as follows: CKAE1/AE3+, EMA+, CK8/18+, CK7+, CK19+, AR negative, p63 focally +, Ki67 25%, rare cells GCDFP15+, p53+.

Hydroxyurea: An Old Drug in Need of New Clinical Trials in Myeloproliferative Neoplasms?

Hydroxyurea (Hu) has been a front-line therapeutic agent for myeloproliferative neoplasms (MPN) for many years and still enjoys the endorsement of experts in the field. However, several publications have reported sub-optimal response, the need for treatment interruption because of cytopenias and lack of sustained response. In all these studies, Hu was used as continuous therapy at a daily dose ranging from 500mg to 3000mg. At our Centre we have used Hu as intermittent therapy (akin to schedules used in patients with solid tumours) at 20-30mg/Kg doses, given as a single dose, twice or thrice weekly. We have consistently observed sustained responses without troublesome cytopenias. Concurrent anti-platelet therapy was given on the basis of the results of whole blood platelet aggregation studies, achieving effective thromboprophylaxis. In this report we present our experience in 118 patients treated with intermittent Hu during the past 30 years (median follow-up 8.5 yrs): polycythemia vera – 29; essential thrombocythemia – 84; primary myelofibrosis – 5. Based on the pharmacokinetics of Hu and our experience, we speculate that the efficacy of intermittent Hu therapy without troublesome myelotoxicity over long periods of time is attributable to the following: i) higher plasma level from intake of Hu as a single dose; ii) higher uptake of Hu by cells with higher mitotic activity (i.e. the abnormal clone); and iii) unhindered, normal haemopoiesis on the drug free days each week. We hope that this article will generate interest and contemplation, leading to further publications from Centres using intermittent Hu therapy and randomized clinical studies to compare the two dosage schedules (Continuous Vs Intermittent) in MPN patients.

ALK rearranged Spitz melanocytoma: a clinicopathological and molecular genetic analysis of two cases

Objective: To investigate the clinicopathological, immunohistochemical and molecular characteristics of cutaneous ALK-rearranged Spitz melanocytoma. Methods: Two cases of cutaneous ALK-rearranged Spitz melanocytoma from outside hospital consultations in Department of Pathology, Affiliated Cancer Hospital of Fudan University in August 2020 and in Shanghai Ackermann Medical Laboratory in June 2022 were collected. The clinicopathological features, immunophenotypes and molecular profiles of two patients with cutaneous Spitzoid melanocytic tumor harboring ALK-rearrangement were analyzed. The literatures were reviewed. Results: The study included an 8-year-old boy and an 11-year-old girl, who presented with a polypoid lesion in the skin of right thigh and left auricle measuring 1.0 cm and 1.2 cm, respectively. Histologically, they were composed of medium to large-sized epithelioid to plump spindle cells, arranged in nested, plexiform or fascicular patterns in the superficial dermis. The neoplastic cells had abundant eosinophilic cytoplasm with round to ovoid vesicular nuclei containing prominent eosinophilic nucleoli. One case showed mild to moderate nuclear pleomorphism and mitotic activity (average, 2/mm2). Immunohistochemically, the epithelioid and plump spindle cells showed diffuse and strong staining of S-100 protein, SOX10, and ALK (D5F3 and 1A4), but did not express HMB45, PNL2 and MiTF. ALK-rearrangement was detected by fuorescence in situ hybridization in both cases. Subsequent next generation sequence (NGS) analysis identified KANK1::ALK and TPM3:ALK fusions. At 34 and 14 months after surgical resection, both patients remained well with no signs of recurrence or metastasis. Conclusions: ALK-rearranged Spitz melanocytoma represents a morphologically and genetically distinct subset of Spitz melanocytoma, characterized clinically by predilection in children and adolescents, with Spitzoid morphology in plexiform pattern, positive immunohistochemical stains, and rearrangement of ALK. As some cases show atypical features and high mitotic activity, a distinction from Spitz melanoma is warranted.

Morphological and immunohistochemical evaluation in distinguishing post-radiotherapy serous-like endometrial change (PoRSEC) and serous endometrial intraepithelial carcinoma (SEIC).

Uteri from women undergoing chemoradiotherapy (CRT) may show reactive atypia which may mimic serous endometrial intraepithelial carcinoma (SEIC). We aimed to assess the prevalence and morphological/immunohistochemical features of post-radiotherapy serous-like endometrial changes (PoRSEC) in women undergone CRT for locally advanced cervical cancer, with a focus on the differential diagnosis with SEIC. Consecutive patients with locally advanced cervical cancer undergone CRT between 2011 and 2018 were reviewed. Endometrial histological specimens were assessed for the presence of PoRSEC. Twenty-two cases of SEIC were included for comparison. Immunohistochemistry for p53, p16, and Ki67 was performed. Out of 244 reviewed patients, 36 (14.7%) showed PoRSEC. The degree of nuclear atypia was similar between PoRSECs and SEIC. However, a papillary architecture with areas of confluent papillae was only observed in SEIC. SEIC cases showed a high mitotic activity as opposed to PoRSEC cases. The expression of p53 was aberrant in all SEICs but in none of the PoRSECs; however, 13/36 PoRSECs showed p53 positivity in most tumor cells, potentially mimicking a mutation pattern. A block-type p16 expression was observed in all SEICs and in 16/36 PoRSECs. Mean Ki67 expression was 26.9% in SEIC (range 5-70%) and 8.16% in PoRSEC (range 5-35%). While SEIC showed sharp morphological and immunohistochemical demarcation, PoRSEC were more heterogenous and merged imperceptibly with normal endometrium. In conclusion, PoRSEC may mimic SEIC both morphologically and immunohistochemically. However, a papillary architecture with cytological demarcation is typically observed in SEIC but not in PoRSEC.

RAS-Mutant Follicular Thyroid Tumors: A Continuous Challenge for Pathologists.

The classification of thyroid nodules, particularly those with a follicular growth pattern, has significantly evolved. These tumors, enriched with RAS or RAS-like mutations, remain challenging for pathologists due to variables such as nuclear atypia, invasion, mitotic activity, and tumor necrosis. This review addresses the histological correlates of benign, low-risk, and malignant RAS-mutant thyroid tumors, as well as some difficult-to-classify follicular nodules with worrisome features. One prototypical RAS-mutant nodule is non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). The assessment of nuclear characteristics in encapsulated/well-demarcated non-invasive RAS-mutant follicular-patterned tumors helps distinguish between follicular thyroid adenoma (FTA) and NIFTP. Despite this straightforward concept, questions about the degree of nuclear atypia necessary for the diagnosis of NIFTP are common in clinical practice. The nomenclature of follicular nodules lacking clear invasive features with increased mitotic activity, tumor necrosis, and/or high-risk mutations (e.g., TERT promoter or TP53) remains debated. Invasion, particularly angioinvasion, is the current hallmark of malignancy in RAS-mutant follicular-patterned neoplasms, with follicular thyroid carcinoma (FTC) as the model. Assessing the tumor interface is critical, though full capsule evaluation can be challenging. Multiple levels and NRASQ61R-specific immunohistochemistry can aid in identifying invasion. Controversies around vascular invasion persist, with ancillary stains like CD31, ERG, and CD61 aiding in its evaluation. Moreover, the review highlights that invasive encapsulated follicular variant papillary thyroid carcinoma (IEFVPTC) is closely associated with FTC, suggesting the need for better nomenclature. The concept of "high-grade" differentiated carcinomas, applicable to FTC or IEFVPTC with necrosis and/or high mitotic activity, is also discussed.

Optimization, Characterization, and Comparison of Two Luciferase-Expressing Mouse Glioblastoma Models.

Glioblastoma (GBM) is the most aggressive brain cancer. To model GBM in research, orthotopic brain tumor models, including syngeneic models like GL261 and genetically engineered mouse models like TRP, are used. In longitudinal studies, tumor growth and the treatment response are typically tracked with in vivo imaging, including bioluminescence imaging (BLI), which is quick, cost-effective, and easily quantifiable. However, BLI requires luciferase-tagged cells, and recent studies indicate that the luciferase gene can elicit an immune response, leading to tumor rejection and experimental variation. We sought to optimize the engraftment of two luciferase-expressing GBM models, GL261 Red-FLuc and TRP-mCherry-FLuc, showing differences in tumor take, with GL261 Red-FLuc cells requiring immunocompromised mice for 100% engraftment. Immunohistochemistry and MRI revealed distinct tumor characteristics: GL261 Red-FLuc tumors were well-demarcated with densely packed cells, high mitotic activity, and vascularization. In contrast, TRP-mCherry-FLuc tumors were large, invasive, and necrotic, with perivascular invasion. Quantifying the tumor volume using the HALO® AI analysis platform yielded results comparable to manual measurements, providing a standardized and efficient approach for the reliable, high-throughput analysis of luciferase-expressing tumors. Our study highlights the importance of considering tumor engraftment when using luciferase-expressing GBM models, providing insights for preclinical research design.

Proposed diagnostic and prognostic markers of primary malignant hepatic vascular neoplasms

IntroductionPrimary malignant hepatic vascular tumors with various malignant potentials include epithelioid hemangioendothelioma (EHE) and angiosarcoma (AS), which may overlap pathologically. This study aimed to compare the pathological findings of hepatic EHE with those of AS, in association with patient outcomes.MethodsFifty-nine histologically confirmed patients with 34 EHE and 25 AS were admitted to a tertiary hospital from 2003 to 2020. Their EHE and AS pathological features were compared. Immunohistochemistry for CD31, ERG, CAMTA-1, TFE3, P53, and Ki-67 labeling was performed on paraffin-embedded blocks. Markers, along with histological findings, were analyzed for the purposes of diagnostic and prognostic significance by multivariate analysis.ResultsCAMTA-1 was 91.2% positive in EHE, but negative in AS (p = < 0.001). AS was significantly correlated to an aberrant p53 expression, high Ki-67 labeling, and high mitotic activity, compared to EHE (all, p = < 0.001). EHE can be classified as low grade (LG) and high grade (HG) using the prognostic values of mitotic activity and ki-67 labeling (sensitivity = 1, specificity = 1). Low grade-EHE showed significantly better overall survival than high grade-EHE (p = 0.020).ConclusionsImmunohistochemistry for CAMTA-1, P53, and Ki-67 labeling may help distinguish EHE and AS in histologically ambiguous cases, especially small biopsied tissue. Moreover, the combination of mitotic activity and Ki-67 labeling can be a prognostic factor for EHE with various clinical features.

Effects of Tetrahydrolipstatin on Glioblastoma in Mice: MRI-Based Morphologic and Texture Analysis Correlated with Histopathology and Immunochemistry Findings-A Pilot Study.

This study aimed to investigate the effects of tetrahydrolipstatin (orlistat) on heterotopic glioblastoma in mice by applying MRI and correlating the results with histopathology and immunochemistry. Human glioblastoma cells were injected subcutaneously into the groins of immunodeficient mice. After tumor growth of >150 mm3, the animals were assigned into a treatment group (n = 6), which received daily intraperitoneal injections of orlistat, and a control group (n = 7). MRI was performed at the time of randomization and before euthanizing the animals. Tumor volumes were calculated, and signal intensities were analyzed. The internal tumor structure was evaluated visually and with texture analysis. Western blotting and protein expression analysis were performed. At histology, all tumors showed high mitotic and proliferative activity (Ki67 ≥ 10%). Reduced fatty acid synthetase expression was measured in the orlistat group (p < 0.05). Based on the results of morphologic MRI-based analysis, tumor growth remained concentric in the control group and changed to eccentric in the treatment group (p < 0.05). The largest area under the receiver operating curve of the predictors derived from the texture analysis of T2w images was for wavelet transform parameters WavEnHL_s3 and WavEnLH_s4 at 0.96 and 1.00, respectively. Orlistat showed effects on heterotopically implanted glioblastoma multiforme in MRI studies of mice based on morphologic and texture analysis.

Imaging Gigantic Small Bowel Gastrointestinal Stromal Tumours Through Different Radiological Lenses: A Case Report

Gastrointestinal stromal tumours (GIST) account for 1–3% of all the gastrointestinal (GI) neoplasms. It is the most common mesenchymal tumour in the Gl tract. The majority of GISTs are KIT gene positive; however, it is necessary to diagnose them pre-operatively. Here, the authors report the case of a 65-year-old male who presented with pain and a lump in the umbilical region for the last 2 years. On abdominal ultrasound, there was a heterogeneously hypoechoic mass in the umbilical region, with lobulated margins and central necrotic areas. On small bowel series, the core of the mass showed faint contrast opacification. Contrast-enhanced CT of the abdomen showed a heterogeneously enhancing, lobulated exophytic lesion arising from the small bowel loops, the central core of the lesion demonstrating an air-contrast level. Under ultrasound guidance, the lesion was biopsied. Histopathological findings were suggestive of a spindle cell tumour. The sample was c-KIT positive. Hence, the diagnosis of GIST was confirmed. The patient was given imatinib after resection of the mass. Usually, a GIST of larger size has higher malignant and metastatic potential; however, this article shows a gigantic small bowel GIST with cavitation and heterogeneity in different imaging modality, and still has no metastasis on imaging or high mitotic activity, and nuclear atypia on histopathology. A radiologist should also know the imaging pattern on conventional imaging and ultrasound, apart from usual cross-sectional imaging.

Low Mitotic Activity in Papillary Thyroid Cancer: A Marker for Aggressive Features and Recurrence.

The significance of low mitotic activity in papillary thyroid cancer (PTC) is largely undefined. We aimed to determine the behavioral landscape of PTC with low mitotic activity compared to that of no- and high-mitotic activity. A single-institution consecutive series of PTC patients from 2018-2022 was reviewed. Mitotic activity was defined as no mitoses, low (1-2 mitoses/2 mm2) or high (≥3 mitoses/2 mm2) per the World Health Organization. The 2015 American Thyroid Association risk stratification was applied to the cohort, and clinicopathologic features were compared between groups. For patients with ≥6 months follow-up, Cox regression analyses for recurrence were performed. 640 PTCs were included - 515 (80.5%) no mitotic activity, 110 (17.2%) low mitotic activity, and 15 (2.3%) high mitotic activity. Overall, low mitotic activity exhibited rates of clinicopathologic features including vascular invasion, gross extrathyroidal extension, and lymph node metastases in between those of no- and high-mitotic activity. PTCs with low mitotic activity had higher rates of intermediate- and high-risk ATA risk stratification compared to those with no mitotic activity (p < 0.001). Low mitotic activity PTCs also had higher recurrence rates (15.5% vs. 4.5%, p < 0.001). Low mitotic activity was associated with recurrence, independent of the ATA risk stratification (HR 2.96; 95% CI 1.28-6.87, p = 0.01). Low mitotic activity is relatively common in PTC and its behavior lies within a spectrum between no- and high-mitotic activity. Given its association with aggressive clinicopathologic features and recurrence, low mitotic activity should be considered when risk stratifying PTC patients for recurrence.

Nuclear Localization of Yes-Associated Protein Is Associated With Tumor Progression in Cutaneous Melanoma

Yes-associated protein (YAP), an effector molecule of the Hippo signaling pathway, is expressed at high levels in cutaneous melanoma. However, the role of YAP in melanoma progression according to cellular localization is poorly understood. Tissues from 140 patients with invasive melanoma were evaluated by immunohistochemistry. Flow cytometry, western blotting, viability assays, wound healing assays, verteporfin treatment, and xenograft assays were conducted using melanoma cell lines B16F1 and B16F10 subjected to YapS127A transfection and siYap knockdown. Nuclear YAP localization was identified in 63 tumors (45.0%) and was more frequent than cytoplasmic YAP in acral lentiginous and nodular subtypes (P = .007). Compared with cytoplasmic YAP melanomas, melanomas with nuclear YAP had higher mitotic activity (P = .016), deeper invasion (P < .001), and more frequently metastasized to lymph nodes (P < .001) and distant organs (P < .001). Patients with nuclear YAP melanomas had poorer disease-free survival (P < .001) and overall survival (P < .001). Nuclear YAP was an independent risk factor for distant metastasis (hazard ratio: 3.206; 95% CI, 1.032-9.961; P = .044). Proliferative ability was decreased in siYapB16F1 (P < .001) and siYapB16F10 (P = .001) cells and increased in YapS127AB16F1 (P = .003) and YapS127AB16F10 (P = .002) cells. Cell cycle analysis demonstrated relative G1 retention in siYapB16F1 (P < .001) and siYapB16F10 (P < .001) cells and S retention in YapS127AB16F1 cells (P = .008). Wound healing assays showed that Yap knockdown inhibited cell invasion (siYapB16F1, P = .001; siYapB16F10, P < .001), whereas nuclear YAP promoted it (YapS127AB16F, P < .001; YapS127AB16F1, P = .017). Verteporfin, a direct YAP inhibitor, reduced cellular proliferation in B16F1 (P = .003) and B16F10 (P < .001) cells. Proliferative effects of nuclear YAP were confirmed in xenograft mice (P < .001). In conclusion, nuclear YAP in human melanomas showed subtype specificity and correlated with proliferative activity and proinvasiveness. It is expected that YAP becomes a useful prognostic marker, and its inhibition may be a potential therapy for melanoma patients.

The clinico-pathological spectrum of plaque-type blue naevi and their potential for malignant transformation.

Plaque-type blue naevi are rare melanocytic tumours presenting as large, pigmented plaques at birth or during childhood. There is a risk for malignant transformation, but no larger comprehensive studies exist and the diagnosis is challenging, especially on limited biopsy material. The aim is to describe the clinicopathological features and behaviour of the disease more comprehensively. We retrieved eight plaque-type blue naevi, presenting as large, pigmented plaques (median = 7 cm; range = 3-26) most frequently affecting the scalp (four) followed by the cheek, arm, abdominal wall and gluteal cleft (one each), with a slight female predilection. Median age at time of biopsy was 39.5 years (range = 15-90), but three tumours had been present at birth and one since childhood. Histopathologically, the tumours were poorly circumscribed and composed of cellular fascicles of uniform spindle cells in a background of variably prominent pigmented dendritic cells affecting dermis and subcutaneous tissues. The majority had mutations in GNAQ. One tumour showed malignant transformation, characterised by an expansile nodule of pleomorphic epithelioid melanocytes with rhabdoid morphology, high mitotic activity and areas of necrosis. This patient developed metastatic melanoma to lymph nodes. All patients are alive with a median follow-up of 60 months. Plaque-type blue naevi are diagnostically challenging tumours with risk for malignant transformation. Awareness and familiarity with the salient clinicopathological features are necessary for reliable diagnosis, and long-term clinical follow-up is required to monitor for malignant transformation.

A Single-Center Retrospective Analysis of Kaposi's Sarcoma: Is There a Relationship Between Emmprin/CD147 Expression and Biological Behavior?

Emmprin (CD147/BSG) protein is estimated to play a key role in cell migration and chemoresistance in viral carcinogenesis. However, there are very limited studies investigating the CD147 in the oncogenesis of Kaposi's sarcoma-associated herpesvirus. This study aims to reveal the relationship between CD147 expression with histopathological parameters, disease pattern, and recurrence in Kaposi's sarcoma (KS). The study included 67 patients diagnosed with KS between January 1982 and September 2023. Clinical and histopathological features were analyzed retrospectively. HHV-8, CD31, and CD147 expressions were evaluated by immunohistochemistry. Sixteen (24%) female and 51 (76%) male patients with median age of 64 (10-86) were included in the study. CD147 was positive in 57 (85%) cases and associated with nodular pattern (P = .001), presence of solid/fibrosarcomatous area (P = .005), and high mitotic activity (P = .035). The disease relapsed in 17 (27%) of the 63 patients with median 2 (0-12) years follow-up. While a 5-year relapse-free survival was 48.5% in the CD147 diffuse positive group, it was 83.4% in focal positive and 100% in negative cases (P = .029). Our study exhibited the relationship between CD147 overexpression and recurrence in KS, but the inhomogeneity of the treatment groups and the small number of patients should also be considered. These findings may provide insight into the pathogenesis of KS and the development of targeted therapies in the future.

Biological identity of orbital cavernous venous malformations.

Vascular anomalies comprise a wide spectrum of clinical manifestations related to disturbances in the blood or lymph vessels. They correspond to mainly tumors (especially hemangiomas), characterized by high mitotic activity and proliferation of the vascular endothelium, and malformations, endowed with normal mitotic activity and no hypercellularity or changes in the rate of cell turnover. However, the classifications of these lesions go beyond this dichotomy and consist various systems adapted for and by different clinical subgroups. Thus, the classifications have not reached a consensus and have historically caused confusion regarding the nomenclatures and definitions. Cavernous venous malformations of the orbit, previously called cavernous hemangiomas, are the most common benign vascular orbital lesions in adults. Herein, we have compiled and discussed the various evidences, including clinical, radiological, morphological, and molecular evidence that indicate the non-neoplastic nature of these lesions.