The histomorphological and molecular landscape of colorectal adenomas and serrated lesions.

The 2019 WHO classification of digestive system tumors significantly reformed the classificatory definition of serrated lesions of the colorectal mucosa and added new essential diagnostic criteria for both conventional adenomas and hereditary gastrointestinal polyposis syndromes. Histopathological examination of colorectal adenocarcinoma precursors lesions represents an important segment of daily clinical practice in a pathology department and is essential for the implementation of current colorectal adenocarcinoma secondary prevention strategies. This overview will focus on a schematic histopathological and molecular classification of precursor lesions arising within colorectal mucosa.

Malignant epithelial/exocrine tumors of the pancreas.

Pancreatic malignant exocrine tumors represent the most important cause of cancer-related death for pancreatic neoplasms. The most common tumor type in this category is represented by pancreatic ductal adenocarcinoma (PDAC), an ill defined, stroma-rich, scirrhous neoplasm with glandular differentiation. Here we present the relevant characteristics of the most important PDAC variants, namely adenosquamous carcinoma, colloid carcinoma, undifferentiated carcinoma, undifferentiated carcinoma with osteoclast-like giant cells, signet ring carcinoma, medullary carcinoma and hepatoid carcinoma. The other categories of malignant exocrine tumors, characterized by fleshy, stroma-poor, circumscribed neoplasms, include acinar cell carcinoma (pure and mixed), pancreatoblastoma, and solid pseudopapillary neoplasms. The most important macroscopic, histologic, immunohistochemical and molecular hallmarks of all these tumors, highlighting their key diagnostic/pathological features are presented. Lastly, standardized indications regarding gross sampling and how to compile a formal pathology report for pancreatic malignant exocrine tumors will be provided.

Evolving concepts and use of immunohistochemical biomarkers in flat non-neoplastic urothelial lesions: WHO 2016 classification update with diagnostic algorithm.

CONTEXT: The classification of flat non-neoplastic urothelial lesions has been evolved through the years in the attempt to better define a spectrum of morphologic entities with somewhat overlapping features. Differentiating these lesions is important because of differences in patient management and clinical outcome. Materials and methods and objective: A systematic review of the literature has been carried out in order to (1) assess the most striking clinical features of each lesion and (2) identify those morphological traits and immunophenotypical markers which may aid in the differential diagnosis. RESULTS AND CONCLUSION: Our results point out the importance of a proper definition of flat non-neoplastic urothelial lesions in order to predict clinical behaviour and allow tailored patient management; therefore, we attempted to construct a novel and "easy to use" algorithm for a clear, standardized and evidence-based pathological diagnosis.

The novel family of Warbicin® compounds inhibits glucose uptake both in yeast and human cells and restrains cancer cell proliferation.

Many cancer cells share with yeast a preference for fermentation over respiration, which is associated with overactive glucose uptake and breakdown, a phenomenon called the Warburg effect in cancer cells. The yeast tps1Δ mutant shows even more pronounced hyperactive glucose uptake and phosphorylation causing glycolysis to stall at GAPDH, initiation of apoptosis through overactivation of Ras and absence of growth on glucose. The goal of the present work was to use the yeast tps1Δ strain to screen for novel compounds that would preferentially inhibit overactive glucose influx into glycolysis, while maintaining basal glucose catabolism. This is based on the assumption that the overactive glucose catabolism of the tps1Δ strain might have a similar molecular cause as the Warburg effect in cancer cells. We have isolated Warbicin ® A as a compound restoring growth on glucose of the yeast tps1Δ mutant, showed that it inhibits the proliferation of cancer cells and isolated structural analogs by screening directly for cancer cell inhibition. The Warbicin ® compounds are the first drugs that inhibit glucose uptake by both yeast Hxt and mammalian GLUT carriers. Specific concentrations did not evoke any major toxicity in mice but increase the amount of adipose tissue likely due to reduced systemic glucose uptake. Surprisingly, Warbicin ® A inhibition of yeast sugar uptake depends on sugar phosphorylation, suggesting transport-associated phosphorylation as a target. In vivo and in vitro evidence confirms physical interaction between yeast Hxt7 and hexokinase. We suggest that reversible transport-associated phosphorylation by hexokinase controls the rate of glucose uptake through hydrolysis of the inhibitory ATP molecule in the cytosolic domain of glucose carriers and that in yeast tps1Δ cells and cancer cells reversibility is compromised, causing constitutively hyperactive glucose uptake and phosphorylation. Based on their chemical structure and properties, we suggest that Warbicin ® compounds replace the inhibitory ATP molecule in the cytosolic domain of the glucose carriers, preventing hexokinase to cause hyperactive glucose uptake and catabolism.

Acute acalculous cholecystitis as an early manifestation of COVID-19: case report and literature review.

Background: The novel coronavirus disease 2019 (COVID-19) has rapidly spread worldwide since the outbreak in Wuhan, China, in 2019, becoming a major threat to public health. The most common symptoms are fever, dry cough, shortness of breath, but subjects with COVID-19 may also manifest gastrointestinal symptoms, and in a few cases an involvement of the gallbladder has been observed. Case report: Here we present a case of 50-year-old male with SARS-CoV-2 infection who had abdominal pain, vomiting and diarrhea without respiratory symptoms and was finally diagnosed as acute acalculous cholecystitis (AAC). Laparoscopic cholecystectomy was performed and found a gangrenous gallbladder; the real-time reverse transcription polymerase chain reaction SARS-CoV-2 nucleic acid assay of the bile was negative. We also made a review of the literature and try to understand the hypothetic role of SARS-CoV-2 in the pathogenesis of AAC. Conclusions: We highlighted that it is noteworthy to look at gastrointestinal symptoms in patients with SARS-CoV-2 infection and take into account AAC as a possible complication of COVID-19. Although more evidence is needed to better elucidate the role of the pathogenic mechanisms of the SARS-CoV-2 in AAC, it is conceivable that the hepatobiliary system could be a potential target of SARS-CoV-2.

COVID-19 pandemic impact on cytopathology practice in the post-lockdown period: An international, multicenter study.

BACKGROUND: In a previous worldwide survey, the authors showed a drastic reduction in the number of cytological specimens processed during the coronavirus disease 2019 "lockdown" period along with an increase in malignancy rates. To assess the continued impact of the pandemic on cytological practices around the world, they undertook a second follow-up worldwide survey collecting data from the post-lockdown period (2020). METHODS: Participants were asked to provide data regarding their cytopathology activity during the first 12 weeks of their respective national post-lockdown period (2020), which ranged from April 4 to October 31. Differences between the post-lockdown period and the corresponding 2019 period were evaluated, and the authors specifically focused on rates of malignant diagnoses. RESULTS: A total of 29 respondents from 17 countries worldwide joined the survey. Overall, a lower number of cytological specimens (n = 236,352) were processed in comparison with the same period in 2019 (n = 321,466) for a relative reduction of 26.5%. The overall malignancy rate showed a statistically significant increase (12,442 [5.26%] vs 12,882 [4.01%]; P < .001) during the same time period. Similar results were obtained if both malignancy and suspicious for malignancy rates were considered together (15,759 [6.58%] vs 16,011 [4.98%]; P < .001). CONCLUSIONS: The data showed a persistent reduction in the cytological specimen volume during the post-lockdown period (2020). However, the relative increase in the cytological workload in the late part of the post-lockdown is a promising finding of a slow return to normality.

Global impact of the COVID-19 pandemic on cytopathology practice: Results from an international survey of laboratories in 23 countries.

BACKGROUND: To the authors' knowledge, the impact of the coronavirus disease 2019 (COVID-19) pandemic on cytopathology practices worldwide has not been investigated formally. In the current study, data from 41 respondents from 23 countries were reported. METHODS: Data regarding the activity of each cytopathology laboratory during 4 weeks of COVID-19 lockdown were collected and compared with those obtained during the corresponding period in 2019. The overall number and percentage of exfoliative and fine-needle aspiration cytology samples from each anatomic site were recorded. Differences in the malignancy and suspicious rates between the 2 periods were analyzed using a meta-analytical approach. RESULTS: Overall, the sample volume was lower compared with 2019 (104,319 samples vs 190,225 samples), with an average volume reduction of 45.3% (range, 0.1%-98.0%). The percentage of samples from the cervicovaginal tract, thyroid, and anorectal region was significantly reduced (P < .05). Conversely, the percentage of samples from the urinary tract, serous cavities, breast, lymph nodes, respiratory tract, salivary glands, central nervous system, gastrointestinal tract, pancreas, liver, and biliary tract increased (P < .05). An overall increase of 5.56% (95% CI, 3.77%-7.35%) in the malignancy rate in nongynecological samples during the COVID-19 pandemic was observed. When the suspicious category was included, the overall increase was 6.95% (95% CI, 4.63%-9.27%). CONCLUSIONS: The COVID-19 pandemic resulted in a drastic reduction in the total number of cytology specimens regardless of anatomic site or specimen type. The rate of malignancy increased, reflecting the prioritization of patients with cancer who were considered to be at high risk. Prospective monitoring of the effect of delays in access to health services during the lockdown period is warranted.

Very Rare Liver Neoplasm: Lymphoepithelioma-Like (LEL) Hepatocellular Carcinoma.

A case of lymphoepithelioma-like (LEL) hepatobiliary carcinoma is reported. To date, only 89 cases of this rare neoplasm have been reported, with both hepatocellular and cholangiocellular histotype. The case reported here could be classified as LEL mixed hepatobiliary carcinoma (Hepato-Cholangio), a histotype not reported so far in the LEL variant.

The Tumor Entity Denominated "clear cell-papillary renal cell carcinoma" According to the WHO 2016 new Classification, have the Clinical Characters of a Renal Cell Adenoma as does Harbor a Benign Outcome.

The new WHO 2016 classification of renal neoplasia encounters the new entity called "clear cell papillary renal cell carcinoma" (ccpRCC). The ccpRCC has been long included as a subtype of clear cell RCC histotype and it actually ranges from 2 to 9% in different routinely available cohort of renal carcinomas. Of important note, ccpRCC does not show any recurrences or metastases or lymph-node invasion and the outcome is always good. We reviewed twenty-four publications with available follow-up for patients (no. 362) affected by clear cell papillary RCCs/renal adenomatoid tumours and notably ccpRCC harbors an indolent clinical behavior after a mean of 38 months (3,5 years) of follow-up. This paper reviews the histological, molecular and clinical features characterizing ccpRCC, with the goal of focusing the knowledge of the benign fashion of this new tumour entity, supporting the idea of a new renal cell adenoma recruited morphologically from ex conventional clear cell RCC tumours.

On a Rare Cutaneous Metastasis from a Sacrococcygeal Chordoma.

Chordomas are rare malignant tumors of notochordal origin and are rare locally aggressive ones with a metastatic potential. The skin rarely is seen as metastatic site. We describe a case of an adult woman with cutaneous metastasis of a primary sacral chordoma excised ten years before, which appeared as a painless cutaneous mass located in the dorsal region. Once removed, the surgical specimen was formalin fixed and in paraffin embedded. Sections were stained with haematoxylin-eosin, and histochemical and immunohistochemical investigations were performed. Histologically, the neoplasia was characterized by cords or single tumor cells with an abundant myxoid stroma, conspicuous pale vacuolated cytoplasm (the classic "physaliphorous cells"), and mild nuclear atypia. Mitotic activity was scanty. At immunohistochemistry, the tumor cells were diffusely positive for S-100 protein, pan-keratins, EMA, and vimentin. A diagnosis of cutaneous metastasis of chordoma was performed. This case illustrates a diagnostic challenge because of the unusual presentation of an already rare tumor.

Cathepsin K expression in castration-resistant prostate carcinoma: a therapeutical target for patients at risk for bone metastases.

BACKGROUND: The lysosomal cysteine protease cathepsin K is involved in bone remodeling and is also expressed in the peritumoral stroma of carcinomas arising from different organs. A new generation of cathepsin K inhibitors blocking the RANKL/RANK pathway are being developed. We sought to investigate cathepsin K expression in a cohort of castration-resistant prostate carcinomas. METHODS: Sixteen cases of castration-resistant disease with at least 5 years of follow-up were selected from a cohort of 280 patients who underwent surgery. Cathepsin K was evaluated on formalin-fixed and paraffin-embedded tissue microarrays with 5 tissue spots per case. These were scored as high 2+ (≥30% of cells), low 1+ (<30% of cells) or zero (absence), distinguishing tumor cells and peritumoral stroma cells. Low (1+) and absence (0) of scoring were interpreted as negative, and high (2+) as positive. RESULTS: The castration-resistant group was composed of 15 acinar adenocarcinomas and 1 neuroendocrine carcinoma, and all showed at least Gleason score 8 at prostatectomy. Two out of 16 cases (12%) scored positive for cathepsin K in tumor cells; and 5 of 16 cases (31%) scored positive in peritumoral stroma cells. The neuroendocrine and acinar subtypes of carcinoma with positive immunoexpression in neoplastic cells developed bone metastases after 4 and 5 years, respectively, and subsequently died. CONCLUSIONS: Patients affected by castration-resistant prostate carcinoma may be tested for cathepsin K, and a positive strong expression (2+) could be a useful predictive biomarker of response to targeted agents, aiding in the selection of patients eligible for these treatments.

Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8 infection in reactive lymphoid tissues: a model for KSHV/HHV-8-related lymphomas?

We set out to analyze the presence of Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus 8 (HHV-8) in different neoplasms occurring in East Africa, a region characterized by a high KSHV/HHV-8 seroprevalence rate and endemic Kaposi's sarcoma (KS). Our results suggest that, in endemic regions of Africa, KSHV/HHV-8 is predominantly associated with KS, independently of HIV status. During the course of this study, other important information came to light. We found the presence of KSHV/HHV-8 in 2 cases of lymph nodes partially involved by Burkitt's lymphoma and KS and in 1 case of multicentric Castleman disease. Our immunophenotypic and molecular data seem to suggest 2 different mechanisms of viral infection are at work in lymphoid cells. On one hand, when B cells show a latent phase infection with KSHV/HHV-8, after the germinal center reaction, naive B cells become resting memory B cells, similarly to Epstein-Barr virus-infected B cells. On the other hand, when lytic genes such as vIL6 are expressed in naive B cells, they may be driven to differentiate into plasmablasts without undergoing germinal center reaction. Interestingly, among KSHV/HHV-8-positive cases, in those in which there was also lymphoma, the neoplastic cells were negative for KSHV/HHV-8. This further confirms that KSHV/HHV-8 is involved in the neoplastic transformation of only certain types of lymphoma, probably in relation to their precursor infected cell. In conclusion, the maturation stage of KSHV/HHV-8-positive B cells as well as the type of viral infection may well determine the morphological, phenotypic, and clinical characteristics of KSHV/HHV-8-associated lymphomas.

Overlapping morphologic and immunophenotypic profiles in small B-cell lymphoma. A report of two cases.

We present two cases of small B-cell lymphomas of particular diagnostic interest because the histological patterns were at variance with their immunophenotype. One of these lymphomas, involving the gallbladder and duodenum, showed a marginal zone lymphoma-like (MALT type) pattern of cellular infiltration with CD5 negativity but (unexpectedly) Cyclin D1 positivity. Fluorescence in situ hybridization analysis of this case was performed because of the aberrant expression of Cyclin D1, and was clearly positive for the Cyclin D1 gene translocation. The second case, occurring in a lymph node, showed the typical growth pattern of a follicular lymphoma but it had an atypical immunophenotype, namely, expression of Cyclin D1, CD10, and Bcl2 and focally Bcl6, accompanied by a lack of CD5 and CD23. The Cyclin D1 gene translocation was detected by fluorescence in situ hybridisation (FISH), whereas c-myc and Bcl2 genes translocation were absent. Numerical chromosomal changes, which were visualized for chromosomes 8, 11, and 18 could be correlated to the aberrant immunoprofile. In this context, we discuss the diagnostic value of Cyclin D1, CD5, CD23, CD10, Bcl6 markers revealed by immunohistochemistry, as well as the significance of detection by FISH of chromosomal translocations such as t(11;14) and t(14;18). The question still remains as to whether such cases should be designated as specific lymphoma entities or reported as unclassifiable and the chromosome aberration reported.

Activity of rituximab monotherapy in refractory splenic marginal zone lymphoma complicated with autoimmune hemolytic anemia.

We describe the case of a 61-year-old patient with refractory splenic marginal zone lymphoma and secondary autoimmune hemolytic anemia, both successfully treated with rituximab. This case demonstrates that rituximab monotherapy might also be a valid therapeutic approach in marginal zone lymphoma and autoimmune hemolytic anemia after failure of first-line treatment. Maintenance therapy, although expensive, could be useful to improve event-free survival in patients with unfavorable clinical behavior.

Polypoid Carcinoma of the Oropharynx with Stromal Ossifying Myofibroblastic Proliferation: A Case Report and Literature Review.

A 76-year-old man reported a worsening difficulty in swallowing, leading to the inability to eat. Physical examination and CT scan revealed a polypoid mass on the posterior oropharynx and obstructing the oropharyngeal space. Histologically, the surface was ulcerated. In the underlying necrotic rim, there was active granulation tissue, and a proliferation of voluminous, globoid elements with hyperchromatic and irregular nucleus, sometimes arranged in a alveolar aggregate. The core of the lesion contained spindle-like myoid elements in interwoven bundles, with trabeculae of osteoid matrix maturing into calcified bone. Immunohistochemistry documented positivity for cytokeratins, epithelial membrane antigen, and P63 in the globoid elements beneath the necrotic rim; strong and diffuse expression of vimentin, smooth muscle actin, and CD99 and BCL2 in the spindle elements; and complete negativity for cytokeratin 5/6, high molecular weight cytokeratin (clone 34ßE12), S100, muscle-specific actin, desmin, CD117, and anaplastic lymphoma kinase. The lesion was morphologically and immunophenotypically classified as a polypoid oropharyngeal carcinoma with ossifying myofibroblastic stromal proliferation.

Urine TMPRSS2: ERG Fusion Transcript as a Biomarker for Prostate Cancer: Literature Review.

Prostate cancer (PCa) is one of the most common male malignancies. Serum prostate-specific antigen (PSA) is one of the most valuable biomarkers in tumor biology and remains the standard marker in detecting and monitoring PCa. However, the high number of serum PSA false positive and false negative results make the identification of novel biomarkers extremely welcome to improve our diagnostic accuracy in detecting PCa and distinguishing the aggressive from the indolent ones. In this study, we analyzed the current role of urinary gene fusion transcripts involving v-ets erythroblastosis virus E26 oncogene homolog, commonly known as ERG, and the androgen-regulated gene transmembrane protease, serine 2 (TMPRSS2), as a biomarker for PCa. Used as a single marker, urinary TMPRSS2:ERG has low sensitivity but high specificity. However, its combination with the other urinary marker PCa antigen 3 (PCA3) has been reported to provide high specificity and sensitivity. Finally, a commercially available assay combining serum PSA with urinary PCA3 and TMPRSS2:ERG provides a 90% specificity and 80% sensitivity in diagnosing PCa. Urinary TMPRSS2:ERG also seems to be indicative of PCa aggressiveness upon biopsy. Should these findings be confirmed in larger studies, urinary TMPRSS2:ERG might become a valuable test not only for diagnosing PCa but also for distinguishing the aggressive tumors from the indolent ones.

Cdk9 regulates neural differentiation and its expression correlates with the differentiation grade of neuroblastoma and PNET tumors.

Cdk9 is a member of the Cdc2-like family of kinases. Its cyclin partners are members of the family of cyclin T (T1, T2a and T2b) and cyclin K. The Cdk9/Cyclin T complex appears to be involved in regulating several physiological processes. Recently, Cdk9 has been identified as a regulator of the differentiation program of several cell types, such as muscle cells, monocytes and lymphocytes, suggesting that it may have a function in controlling specific differentiative pathways. We analyzed whether Cdk9 and Cyclin T1 may be involved in the regulation of neuron and astrocyte differentiation. Cdk9 and Cyclin T1 expression levels were monitored during the differentiation program of neuroblastoma and astrocytoma cell lines. Our results suggest that Cdk9/Cyclin T1 complex may be required for neuron differentiation induced by retinoic acid, because the expression level of the complex varies during differentiation, but no significant changes were observed in its expression in the astrocytoma cell line. In addition, the expression of Cdk9 and Cyclin T1 was evaluated by immunohistochemistry in samples of neuroblastoma, PNET (Primary Neuroectodermal Tumor) and astrocytoma tumors of different grades, in order to assess whether there was a correlation between Cdk9 expression and tumor grading. Our results show that in neuroblastoma and PNET tumor samples Cdk9 is more expressed the more differentiated the tumor is. Conversely, no significant alteration of Cdk9 expression was observed in astrocytoma tumor samples of different grades, thus confirming the results obtained for the cell lines.

Methods to identify molecular expression of mTOR pathway: a rationale approach to stratify patients affected by clear cell renal cell carcinoma for more likely response to mTOR inhibitors.

Since target therapy with mTOR inhibitors plays an important role in the current management of clear cell renal cell carcinoma (RCC), there is an increasing demand for predictive biomarkers, which may help to select patients that are most likely to benefit from personalized treatment. When dealing with formalin-fixed paraffin-embedded (FFPE) cancer tissue specimens, several techniques may be used to identify potential molecular markers, yielding different outcome in terms of accuracy. We sought to investigate and compare the capability of three main techniques to detect molecules performing an active function in mTOR pathway in RCC. Immunohistochemistry (IHC), Western blot (WB) and immunofluorescence (IF) analyses were performed on FFPE RCC tissue specimens from 16 patients by using the following mTOR pathway-related: mTOR (Ser235/236), phospho-mTOR (p-mTOR/Ser2448), phospho-p70S6k (p-p70S6k/Thr389), both monoclonal and polyclonal, phospho-S6Rb (p-S6Rb) and phospho-4EBP1 (p-4EBP1/Thr37/46). No single molecule was simultaneously revealed by all three techniques. Only p-p70S6k was detected by two methods (IHC and IF) using a monoclonal antibody. The other molecules were detected exclusively by one technique, as follows: p-mTOR and polyclonal p-p70S6K by IHC, p70S6K, p-S6Rb and p-4EBP1 by WB, and, finally, mTOR by IF. We found significant differences in detecting mTOR pathway-related active biomarkers by using three common techniques such as IHC, WB and IF on RCC samples. Such results have important implications in terms of predictive biomarker testing, and need to be related to clinical end-points such as responsiveness to targeted drugs by prospective studies.