Mucocele-like Lesions: Radiologic-Pathologic Correlation.

Mucocele-like lesions (MLLs) of the breast are rare lesions described as dilated, mucin-filled cysts associated with rupture and extracellular mucin in the surrounding stroma. These lesions are of clinical concern because they can coexist with a spectrum of atypical and malignant findings, including atypical ductal hyperplasia, ductal carcinoma in situ, and invasive carcinoma including mucinous carcinoma. Imaging findings of MLLs are nonspecific and varied, although the most common initial finding is that of incidental coarse heterogeneous calcifications on mammography. Occasionally, an asymmetry or mass may be found with or without calcifications, and such MLLs have a higher rate of upgrade to malignancy at excision. Pathology findings are often descriptive given the small sample received from percutaneous biopsy, and the primary consideration is to report any associated atypia, including atypical ductal hyperplasia. There is consensus in the literature that MLLs with atypia on biopsy should undergo excision because of the average reported 17.5% (20/114) upgrade rate to malignancy. The upgrade rate for MLLs without atypia averages 4.1% (14/341). Therefore, imaging surveillance may be a reasonable alternative to excision for MLLs with no atypia on a case-by-case basis. We review MLL imaging findings, pathology findings, and clinical management and present 3 cases from our institution to add to the literature on these rare lesions.

Proteogenomic insights suggest druggable pathways in endometrial carcinoma.

We characterized a prospective endometrial carcinoma (EC) cohort containing 138 tumors and 20 enriched normal tissues using 10 different omics platforms. Targeted quantitation of two peptides can predict antigen processing and presentation machinery activity, and may inform patient selection for immunotherapy. Association analysis between MYC activity and metformin treatment in both patients and cell lines suggests a potential role for metformin treatment in non-diabetic patients with elevated MYC activity. PIK3R1 in-frame indels are associated with elevated AKT phosphorylation and increased sensitivity to AKT inhibitors. CTNNB1 hotspot mutations are concentrated near phosphorylation sites mediating pS45-induced degradation of ß-catenin, which may render Wnt-FZD antagonists ineffective. Deep learning accurately predicts EC subtypes and mutations from histopathology images, which may be useful for rapid diagnosis. Overall, this study identified molecular and imaging markers that can be further investigated to guide patient stratification for more precise treatment of EC.

MST4: A Potential Oncogene and Therapeutic Target in Breast Cancer.

The mammalian STE 20-like protein kinase 4 (MST4) gene is highly expressed in several cancer types, but little is known about the role of MST4 in breast cancer, and the function of MST4 during epithelial-mesenchymal transition (EMT) has not been fully elucidated. Here we report that overexpression of MST4 in breast cancer results in enhanced cell growth, migration, and invasion, whereas inhibition of MST4 expression significantly attenuates these properties. Further study shows that MST4 promotes EMT by activating Akt and its downstream signaling molecules such as E-cadherin/N-cadherin, Snail, and Slug. MST4 also activates AKT and its downstream pro-survival pathway. Furthermore, by analyzing breast cancer patient tissue microarray and silicon datasets, we found that MST4 expression is much higher in breast tumor tissue compared to normal tissue, and significantly correlates with cancer stage, lymph node metastasis and a poor overall survival rate (p < 0.05). Taken together, our findings demonstrate the oncogenic potential of MST4 in breast cancer, highlighting its role in cancer cell proliferation, migration/invasion, survival, and EMT, suggesting a possibility that MST4 may serve as a novel therapeutic target for breast cancer.

MicroRNAs within the Basal-like signature of Quadruple Negative Breast Cancer impact overall survival in African Americans.

We previously found that QNBC tumors are more frequent in African Americans compared to TNBC tumors. To characterize this subtype further, we sought to determine the miRNA-mRNA profile in QNBC patients based on race. Both miRNA and mRNA expression data were analyzed from TCGA and validated using datasets from the METABRIC, TCGA proteomic, and survival analysis by KMPLOT. miRNA-mRNAs which include FOXA1 and MYC (mir-17/20a targets); GATA3 and CCNG2 (mir-135b targets); CDKN2A, CDK6, and B7-H3 (mir-29c targets); and RUNX3, KLF5, IL1-ß, and CTNNB1 (mir-375 targets) were correlated with basal-like and immune subtypes in QNBC patients and associated with a worse survival. Thus, QNBC tumors have an altered gene signature implicated in racial disparity and poor survival.

Discordance Between Immunohistochemistry and In Situ Hybridization to Detect HER2 Overexpression/Gene Amplification in Breast Cancer in the Modern Age: A Single Institution Experience and Pooled Literature Review Study.

BACKGROUND: Human epidermal growth factor 2 (HER2) amplification and/or overexpression occurs in 12% to 25% of breast cancers. Accurate detection of HER2 is critical in predicting response to HER2-targeted therapy. Both immunohistochemistry (IHC) and in situ hybridization (ISH) are FDA-approved methods for detecting HER2 status because its protein overexpression is largely attributable to gene amplification. However, variable discordant results between IHC and ISH have been reported. METHODS: We determined the frequency of HER2 IHC/ISH discordance in these patients and also performed a pooled literature review analysis. RESULTS: Of the 1125 consecutive primary or metastatic breast cancers with HER2 IHC and ISH performed simultaneously between 2015 and 2020, 84.6% had an unequivocal HER2 status. Discordance was found in 30 cases from 26 patients, including 13 IHC-/ISH+ and 17 IHC+/ISH-, representing 1.6% and 11.9% of IHC- and IHC+ cases, respectively. Review of the literature between 2001 and 2020 identified 46 relevant studies, with a total of 43,468 cases with IHC and ISH performed. The IHC-/ISH+ and IHC+/ISH- discordances were seen in all antibody clones and ISH methods used. The IHC+/ISH- discordance was significantly higher than IHC-/ISH+ (13.8% vs. 3%, P < .0001). The overall discordance constituted 4% of all cases and 5.4% of those with an unequivocal IHC status. Significantly lower incongruities for both IHC-/ISH+ and IHC+/ISH- were found in those published after 2018. The discordances probably reflect altered biology of HER2 oncogene/oncoprotein. Routinely performing both IHC and ISH may uncover such cases to prevent denial of potentially beneficial targeted therapy.

Quantitative Image Analysis of Human Epidermal Growth Factor Receptor 2 Immunohistochemistry for Breast Cancer: Guideline From the College of American Pathologists.

CONTEXT.­: Advancements in genomic, computing, and imaging technology have spurred new opportunities to use quantitative image analysis (QIA) for diagnostic testing. OBJECTIVE.­: To develop evidence-based recommendations to improve accuracy, precision, and reproducibility in the interpretation of human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) for breast cancer where QIA is used. DESIGN.­: The College of American Pathologists (CAP) convened a panel of pathologists, histotechnologists, and computer scientists with expertise in image analysis, immunohistochemistry, quality management, and breast pathology to develop recommendations for QIA of HER2 IHC in breast cancer. A systematic review of the literature was conducted to address 5 key questions. Final recommendations were derived from strength of evidence, open comment feedback, expert panel consensus, and advisory panel review. RESULTS.­: Eleven recommendations were drafted: 7 based on CAP laboratory accreditation requirements and 4 based on expert consensus opinions. A 3-week open comment period received 180 comments from more than 150 participants. CONCLUSIONS.­: To improve accurate, precise, and reproducible interpretation of HER2 IHC results for breast cancer, QIA and procedures must be validated before implementation, followed by regular maintenance and ongoing evaluation of quality control and quality assurance. HER2 QIA performance, interpretation, and reporting should be supervised by pathologists with expertise in QIA.

Mitochondrial DNA Repair through OGG1 Activity Attenuates Breast Cancer Progression and Metastasis.

Production of mitochondrial reactive oxygen species and integrity of mitochondrial DNA (mtDNA) are crucial in breast cancer progression and metastasis. Therefore, we evaluated the role of mtDNA damage in breast cancer by genetically modulating the DNA repair enzyme 8-oxoguanine DNA glycosylase (OGG1) in the PyMT transgenic mouse model of mammary tumorigenesis. We generated mice lacking OGG1 (KO), mice overexpressing human OGG1 subunit 1α in mitochondria (Tg), and mice simultaneously lacking OGG1 and overexpressing human OGG1 subunit 1α in mitochondria (KO/Tg). We found that Tg and KO/Tg mice developed significantly smaller tumors than KO and wild-type (WT) mice after 16 weeks. Histologic analysis revealed a roughly 2-fold decrease in the incidence of lung metastases in Tg mice (33.3%) compared to WT mice (62.5%). Furthermore, lungs from Tg mice exhibited nearly a 15-fold decrease in the average number of metastatic foci compared with WT mice (P ≤ 0.05). Primary tumors isolated from Tg mice also demonstrated reduced total and mitochondrial oxidative stress, diminished mtDNA damage, and increased mitochondrial function. Targeting hOGG1 to the mitochondria protected cells from mtDNA damage, resulting in downregulation of HIF1α and attenuated phosphorylation of Akt. Collectively, we demonstrate proof of concept that mtDNA damage results in breast cancer progression and metastasis in vivo. Moreover, our findings offer new therapeutic strategies for modulating the levels of mtDNA repair enzymes to delay or stall metastatic progression.

Splenic lymphangioma.

Splenic lymphangioma is a rare malformation of the splenic lymphatic channels, mostly seen in children. It is characterized by the presence of cysts, resulting from increases in the size and number of thin-walled lymphatic vessels that are abnormally interconnected and dilated. The condition may be restricted to the spleen, but in most cases it involves multiple organs (systemic lymphangiomatosis). The clinical picture is variable; small lesions are often incidentally detected through imaging studies, while larger lesions can result in compression of organs, causing pain or rupture even after minor trauma. Therefore, splenic lymphangiomas should be considered in the differential diagnosis of splenomegaly or left upper quadrant pain even among adults and should be immediately treated with splenectomy; delay in the therapeutic intervention can lead to life-threatening complications.

Increased reactive oxygen species, metabolic maladaptation, and autophagy contribute to pulmonary arterial hypertension-induced ventricular hypertrophy and diastolic heart failure.

Pulmonary arterial hypertension (PAH) is a debilitating and deadly disease with no known cure. Heart failure is a major comorbidity and a common cause of the premature death of patients with PAH. Increased asymmetrical right ventricular hypertrophy and septal wall thickening compress the left ventricular cavity and elicit diastolic heart failure. In this study, we used the Sugen5416/hypoxia/normoxia-induced PAH rat to determine whether altered pyridine nucleotide signaling in the failing heart contributes to 1) increased oxidative stress, 2) changes in metabolic phenotype, 3) autophagy, and 4) the PAH-induced failure. We found that increased reactive oxygen species, metabolic maladaptation, and autophagy contributed to the pathogenesis of right ventricular remodeling and hypertrophy that lead to left ventricular diastolic dysfunction. In addition, arterial elastance increased in PAH rats. Glucose-6-phosphate dehydrogenase is a major source of pyridine molecule (nicotinamide adenine dinucleotide phosphate), which is a substrate for nicotinamide adenine dinucleotide phosphate oxidases in the heart. Dehydroepiandrosterone, a 17-ketosteroid that reduces pulmonary hypertension and right ventricular hypertrophy, inhibited glucose-6-phosphate dehydrogenase, decreased oxidative stress, increased glucose oxidation and acetyl-coA, and reduced autophagy in the hearts of PAH rats. It also decreased arterial stiffness and improved left ventricular diastolic function. These findings demonstrate that pyridine nucleotide signaling, at least partly, mediates PAH-induced diastolic heart failure, and that reduction of glucose-6-phosphate dehydrogenase-derived nicotinamide adenine dinucleotide phosphate is beneficial to improve left ventricle diastolic function.

Contractile protein expression is upregulated by reactive oxygen species in aorta of Goto-Kakizaki rat.

Although it is known that blood vessels undergo remodeling in type 2 diabetes (T2D), the signaling pathways that underlie the structural and functional changes seen in diabetic arteries remain unclear. Our objective was to determine whether the remodeling in type 2 diabetic Goto-Kakizaki (GK) rats is evoked by elevated reactive oxygen species (ROS). Our results show that aortas from GK rats produced greater force (P < 0.05) in response to stimulation with KCl and U46619 than aortas from Wistar rats. Associated with these changes, aortic expression of contractile proteins (measured as an index of remodeling) and the microRNA (miR-145), which act to upregulate transcription of contractile protein genes, was twofold higher (P < 0.05) in GK than Wistar (age-matched control) rats, and there was a corresponding increase in ROS and decrease in nitric oxide signaling. Oral administration of the antioxidant Tempol (1 mmol/l) to Wistar and GK rats reduced (P < 0.05) myocardin and calponin expression. Tempol (1 mmol/l) decreased expression of miR-145 in Wistar and GK rat aorta. To elucidate the mechanism through which ROS increases miR-145, we measured their levels in freshly isolated aorta and cultured aortic smooth muscle cells incubated for 12 h in the presence of H2O2 (300 µmol/l). H2O2 increased expression of miR-145, and there were corresponding nuclear increases in myocardin, a miR-145 target protein. Intriguingly, H2O2-induced expression of miR-145 was decreased by U0126 (10 µmol/l), a MEK1/2 inhibitor, and myocardin was decreased by anti-miR-145 (50 nmol/l) and U0126 (10 µmol/l). Our novel findings demonstrate that ROS evokes vascular wall remodeling and dysfunction by enhancing expression of contractile proteins in T2D.

Regulation and distribution of squirrel monkey chorionic gonadotropin and secretogranin II in the pituitary.

Secretogranin II (SgII) is a member of the granin family of proteins found in neuroendocrine and endocrine cells. The expression and storage of SgII in the pituitary gland of Old World primates and rodents have been linked with those of luteinizing hormone (LH). However, New World primates including squirrel monkeys do not express LH in the pituitary gland, but rather CG is expressed. If CG takes on the luteotropic role of LH in New World primates, SgII may be associated with the expression and storage of CG in the pituitary gland. The goal of this study was to evaluate the regulation and distribution of CG and SgII in the squirrel monkey. A DNA fragment containing approximately 750 bp of squirrel monkey SgII promoter was isolated from genomic DNA and found to contain a cyclic-AMP response element that is also present in the human SgII promoter and important for GnRH responsiveness. The squirrel monkey and human SgII promoters were similarly activated by GnRH in luciferase reporter gene assays in LßT2 cells. Double immunofluorescence microscopy demonstrated close association of SgII and CG in gonadotrophs of squirrel monkey pituitary gland. These results suggest that CG and SgII have a similar intercellular distribution and are coregulated in squirrel monkey pituitary gland.

Primary renal zygomycotic infarction mimicking renal neoplasia in an immunocompetent patient.

Isolated renal infections with fungal organisms of the class Zygomycetes are rare, but these infections are most frequently seen in patients who are immunocompromised. We report the case of a 45-year-old African American man who presented with symptoms of right-sided pyelonephritis, including fever, dysuria, and flank pain. The patient's history was significant only for sickle cell trait, and no evidence of immunosuppression was identified. Renal ultrasound imaging revealed a hypoechoic lesion in the superior pole of the right kidney, and the radiologic differential diagnoses included neoplasm, abscess, and infarct. Urine cultures were negative, but urinalysis showed white blood cells, which were too numerous to count. A computed tomography scan of the abdomen and pelvis performed 2 weeks after the initial presentation showed a slight increase in the renal mass, despite antimicrobial therapy, and a right nephrectomy was subsequently performed. On gross sectioning, an 8.5-cm well-circumscribed lesion was identified in the upper pole of the kidney. Microscopic sections showed extensive necrosis of the renal parenchyma, and, in areas of both infarcted and viable renal tissue, large, broad, aseptate fungal hyphae with irregular branching. Angioinvasion with associated thrombosis was seen in the renal tissue. The morphologic features of the organism were most compatible with that of a zygomycete. No evidence of disseminated fungal disease was identified on imaging studies. This case represents a successful outcome of a rarely reported isolated renal zygomycosis in a patient with no known underlying risk factors for the infection and illustrates the wide range of clinical presentations with which zygomycotic infections may present.

Tricuspid valve and pacemaker endocarditis due to Pseudallescheria boydii (Scedosporium apiospermum).

We report a case of native valve and pacemaker endocarditis in a 78-year-old male with diabetes mellitus who died after cardiac surgery. At autopsy, tricuspid valve vegetations and lung abscesses containing thick, hyaline, septate, and branching hyphae were present. The culture identified Scedosporium apiospermum, an infrequent cause of opportunistic infections in immunocompromised hosts.

A case of bone metaplasia of the gallbladder epithelium.

The case of a 53-year-old female with abdominal pain is presented. Abdominal ultrasound was unremarkable, a HIDA scan demonstrated biliary dyskinesia, and a computed tomography scan of the abdomen and pelvis revealed an intraluminal gallbladder hyperdensity suspicious for a gallstone. A laparoscopic cholecystectomy was performed and, on pathologic examination, no gallstones were present. Microscopically, a focus of bone metaplasia of the gallbladder mucosa was noted. No other lesions were identified. Bone metaplasia of the gallbladder is a rare event of unknown clinical significance that may be clinically confused with cholelithiasis affecting treatment options.

Sentinel node in melanoma patients: triple negativity with routine techniques and PCR as positive prognostic factor for survival.

Lymph node mapping and sentinel lymph node biopsy are currently used to stage patients with cutaneous malignant melanoma. Immunohistochemical stains contribute to the detection of micrometastases; however, molecular biology techniques are associated with better diagnostic sensitivity. Sixty sentinel lymph nodes were included in this study. The primary lesions were malignant melanoma stage I or II, with a follow-up of longer than 2 years. Sentinel lymph nodes were studied with hematoxylin-eosin, immunohistochemistry for S-100 and HMB-45, and molecular biology techniques (reverse transcription (RT)-PCR) for the detection of tyrosinase messenger RNA. In 15 of 60 cases (25%), tyrosinase was detected by RT-PCR; three of these cases were also positive by immunohistochemistry. The population was divided into three groups: (i) hematoxylin-eosin-/immunohistochemistry+/molecular biology techniques+ (3 cases); (ii) hematoxylin-eosin-/immunohistochemistry-/molecular biology techniques+ (12 cases); (iii) hematoxylin-eosin-/immunohistochemistry-/molecular biology techniques- (45 cases). Correlation of the groups with overall survival showed the following: (i) 2 of 3 patients died (67%); (ii) 5 of 12 died (42%), and (iii) all 45 patients are alive, with no lymphadenectomy and a median follow-up of 84 months. The inclusion of molecular biology techniques appears to be of great value for the detection of sentinel lymph node micrometastases in patients with cutaneous malignant melanoma. In our series, those patients who showed negativity with all the three methods had a null recurrence rate. Therefore, this triple negativity could be a positive prognostic factor for overall survival. Our findings suggest the possibility of molecular oncological staging, which would allow the selection of patients with submicroscopic metastases for a complete treatment.

Pseudofungi in pericolic lymph nodes.

We report a case of extensive pseudofungi in the pericolic lymph nodes. A 45-year-old man presented with lower abdominal discomfort, and large solid and cystic masses were discovered in the pelvic cavity by computed tomography. Debulking of the masses (by means of a Hartmann operation) was performed under the clinical impression of a pelvic sarcoma, and histologically the masses demonstrated features of a malignant gastrointestinal stromal tumor. All pericolic lymph nodes demonstrated multiple septate hyphae-like structures with pigmentation, particularly in the subcapsular sinuses. These structures showed positive staining with periodic acid-Schiff, but Gomori methenamine silver staining was negative. The structures appeared to be composed of iron, phosphorus, and calcium by Perls iron and von Kossa stains and revealed deposition of electron-dense granules on electron microscopic examination. Energy-dispersive radiographic micro-analysis showed the structures to contain phosphorus, sulfur, potassium, calcium, and iron. Pseudofungi can be misinterpreted as true fungi with septate hyphae; therefore, a careful morphologic examination with appropriate special stains is mandatory.

Sentinel lymph node: detection of micrometastases of melanoma in a molecular study.

INTRODUCTION: Lymph node status in patients with cutaneous malignant melanoma is the most important prognostic factor. Patients with clinically positive nodes (stage III) should undergo therapeutic lymphadenectomy; however, the surgical approach to the regional disease in patients with negative clinical examination (stage I and II) is still controversial. Selective lymphadenectomy consists of the intraoperative identification of the first node in the nodal basin, the sentinel lymph node (SLN). Routine examination, serial sectioning, and immunohistochemistry may underestimate the presence of tumor cells. PCR is a molecular biology technique that may be useful for the detection of malignant melanoma nodal metastases in the SLN. AIM: The aim of this study was to use tyrosinase messenger RNA (mRNA) amplification for the detection of micrometastases in fresh frozen SLNs. METHODS: 46 hematoxylin-eosin (HE)-negative sentinel node samples from 42 patients with malignant melanoma were included in this study. Formalin-fixed paraffin-embedded sections were immunostained with S-100 protein and HMB-45. A central portion of the node was submitted for PCR. This method was accomplished with a combination of reverse transcription and amplification of the tyrosinase complementary DNA and double- round PCR (nested reverse transcriptase [RT]-PCR). RESULTS: In 1 of the 42 SLN-negative patients, immunohistochemistry stains allowed the detection of micrometastases. With molecular biology, 14 of the 42 SLN patients were positive (33%); in another 12 (29%), only the nested RT-PCR was positive. Of the 42 patients, 24 were put into 3 groups and followed for a 5-year period with 1, 7, and 16 patients, respectively, in the groups. The first group involved 1 patient who had provided 2 SLN samples that were found to be SLN-positive using both techniques, immunohistochemistry stains and nested RT-PCR (he had hepatic metastasis and died 24 months after diagnosis). The second group, with only nested RT-PCR positive SLN samples, included 7 of 12 patients who were followed and had a median survival of 37 months; 4 died of widespread metastatic disease, the other 3 patients had event-free survival, but 1 consented to undergo a therapeutic lymphadenectomy as a result of a positive test. The last group consisting of 16 of 32 patients, with complete 5-year survival, who were SLN-negative with both techniques, immunohistochemistry stains and nested RT-PCR. Fourteen of the 16 (88%) were event-free survival during the follow-up, and 2 had local relapse. CONCLUSION: Tyrosinase mRNA amplification may be a negative prognostic factor for the detection of micrometastases in fresh frozen SLNs using molecular biology techniques.

Ganglio centinela: detección de micrometástasis de melanoma maligno / Sentinel lymph node: detection of micrometastases of malignant melanoma

El estudio del ganglio centinela (GC) es esencial en pacientes con melanoma maligno cutáneo estadio I y II ya que provee información indispensable para la correcta estadificación y tratamiento cuando se detectan micrometástasis (linfadenectomía selectiva). Los protocolos para el manejo de los GC deben incluir métodos complementarios que permitan aumentar al máximo la sensibilidad para la detección de micrometástasis, teniendo en cuenta que esta demostrado que con el estudio rutinario se obtiene un número importante de falsos negativos. Estudiamos 240 GC pertenecientes a 162 pacientes con melanoma maligno cutáneo estadios I y II. Los mismos fueron hemiseccionados intraoperatoriamente seleccionándose una lonja central para el estudio de biología molecular, la que fue consevada a -70ºC. El resto del material fue procesado rutinariamente obteniéndose cortes seriados para hematoxilina-eosina (HE) e inmunohistoquímica (IHQ). Los anticuerpos utilizados fueron HMB-45 (DAKO, 1:50) y proteína S-100 (Biogenex, 1:400). 39 GC negativos con HE fueron estudiados con el método de reacción en cadena de polimerasa-transcriptasa reversa (RT-PCR) para la detección del ARNm de la tirosinasa. Se realizaron los controles negativos, positivos y de la integridad del ARN. La presencia de micrometástasis fue correlacionada con el grosor del melanoma cutáneo menor o mayor de 1,5 mm... (TRUNCADO)