Stuti Shroff

Beyond the GIST: Mesenchymal Tumors of the Stomach

Intramural gastric masses arise in the wall of the stomach (generally within the submucosa or muscularis propria), often with intact overlying mucosa. These tumors are typically mesenchymal in origin and have overlapping radiologic appearances. A combination of features such as location, attenuation, enhancement, and growth pattern may suggest one diagnosis over another. Gastrointestinal stromal tumors (GISTs) account for the majority of intramural tumors and can vary widely in appearance, from small intraluminal lesions to exophytic masses that protrude into the peritoneal cavity, commonly with areas of hemorrhage or necrosis. A well-circumscribed mass measuring -70 to -120 HU is a lipoma. Leiomyomas usually manifest as low-attenuation masses at the gastric cardia. Homogeneous attenuation is a noteworthy characteristic of schwannomas, particularly for larger lesions that might otherwise be mistaken for GISTs. A hypervascular mass in the antrum is a common manifestation of glomus tumors. Hemangiomas are also hypervascular but often manifest in childhood. Inflammatory fibroid polyps usually arise as a polypoid mass in the antrum. Inflammatory myofibroblastic tumors are infiltrative neoplasms with a propensity for local recurrence. Plexiform fibromyxomas are rare, usually antral tumors. Carcinoid tumors are epithelial in origin, but often submucosal in location, and therefore should be distinguished from other intramural lesions. Multiple carcinoid tumors are associated with hypergastrinemia, either in the setting of chronic atrophic gastritis or Zollinger-Ellison syndrome. Sporadic solitary carcinoid tumors not associated with hypergastrinemia have a higher rate of metastasis. Histopathologic analysis, including immunohistochemistry, is usually required for diagnosis of intramural masses.

SOX9: a useful marker for pancreatic ductal lineage of pancreatic neoplasms

Previous studies showed that SOX9 plays a critical role in pancreatic ductal development. The aim of this study was to evaluate SOX9 as a marker for pancreatic ductal lineage. SOX9 expression was evaluated by immunohistochemistry in 146 benign pancreas (BP), 136 pancreatic ductal adenocarcinomas, 47 pancreatic intraepithelial neoplasia (PanIN), 21 intraductal papillary mucinous neoplasms (IPMNs), 14 mucinous cystic neoplasms, 10 serous cystadenomas, 39 pancreatic neuroendocrine tumors, 9 acinar cell carcinomas, and 23 solid pseudopapillary neoplasms. Nuclear expression of SOX9 was detected in the centroacinar cells and ductal cells, but not in acinar or endocrine cells in 100% BP. Focal or diffuse SOX9 expression was detected in 100% PanINs, 100% IPMNs, 100% mucinous cystic neoplasms, 100% serous cystadenomas, 89.0% pancreatic ductal adenocarcinomas, 2.6% pancreatic neuroendocrine tumors, 11.1% acinar cell carcinomas, and 0% solid pseudopapillary neoplasms. SOX9 expression was lower in PanIN2 and PanIN3 than in PanIN1 lesions (P < .01). Compared with BP, IPMN had lower SOX9 expression (P < .05). No correlation between SOX9 expression and other clinicopathologic parameters was identified. Our study showed that SOX9 is expressed in centroacinar and ductal epithelial cells of BP and is a useful marker for pancreatic ductal lineage of pancreatic neoplasms.

Differential Delta expression underlies the diversity of sensory organ patterns among the legs of the Drosophila adult

Many studies have shown that morphological diversity among homologous animal structures is generated by the homeotic (Hox) genes. However, the mechanisms through which Hox genes specify particular morphological features are not fully understood. We have addressed this issue by investigating how diverse sensory organ patterns are formed among the legs of the Drosophila melanogaster adult. The Drosophila adult has one pair of legs on each of its three thoracic segments (the T1-T3 segments). Although homologous, legs from different segments have distinct morphological features. Our focus is on the formation of diverse patterns of small mechanosensory bristles or microchaetae (mCs) among the legs. On T2 legs, the mCs are organized into a series of longitudinal rows (L-rows) precisely positioned along the leg circumference. The L-rows are observed on all three pairs of legs, but additional and novel pattern elements are found on T1 and T3 legs. For example, at specific positions on T1 and T3 legs, some mCs are organized into transverse rows (T-rows). Our studies indicate that the T-rows on T1 and T3 legs are established as a result of Hox gene modulation of the pathway for patterning the L-row mC bristles. Our findings suggest that the Hox genes, Sex combs reduced (Scr) and Ultrabithorax (Ubx), establish differential expression of the proneural gene achaete (ac) by modifying expression of the ac prepattern regulator, Delta (Dl), in T1 and T3 legs, respectively. This study identifies Dl as a potential link between Hox genes and the sensory organ patterning hierarchy, providing insight into the connection between Hox gene function and the formation of specific morphological features.

The Expression of PTEN Is Associated With Improved Prognosis in Patients With Ampullary Adenocarcinoma After Pancreaticoduodenectomy

CONTEXT Phosphatase and tensin homolog (PTEN) is one of the most frequently inactivated tumor suppressor genes in sporadic cancers. Somatic mutations of PTEN occur in many tumors including those of the gastrointestinal and hepatobiliary tracts. Loss of PTEN expression is associated with poor prognosis in patients with metastatic colonic adenocarcinoma, gastroesophageal junction adenocarcinoma, gastric adenocarcinoma, and pancreatic ductal adenocarcinoma. OBJECTIVE To study the expression of PTEN and its significance in ampullary adenocarcinoma (AA). DESIGN We constructed tissue microarrays by using archival tissue from 92 patients (55 males, 37 females; median age, 63 years; age range, 37 to 87 years) with previously untreated AA who underwent pancreaticoduodenectomy at our institution. PTEN expression was evaluated by immunohistochemistry, scored semiquantitatively (based on staining intensity and percentage positive tumor cells), and correlated with clinicopathologic features and survival. RESULTS Of 92 cases, 23 (25.0%) were PTEN negative. Loss of PTEN expression correlated with lymph node metastasis (P = .004), advanced American Joint Committee on Cancer (AJCC) stage (P = .02), and higher frequency of recurrence (P = .03). Patients with PTEN-negative tumors had shorter disease-free survival (DFS, mean: 89.0 ± 20.8 months) and overall survival (OS, mean: 93.1 ± 19.1 months) than those with PTEN-positive tumors (DFS, mean: 161.4 ± 11.7 months, P = .01; OS, mean: 175.4 ± 11.0 months, P = .001). In multivariate analyses, PTEN expression was a prognostic factor for both DFS and OS, independent of AJCC stage, lymph node status, pathologic tumor (pT) stage, and differentiation. CONCLUSIONS Loss of PTEN expression is associated with poor DFS and OS in patients with AA after curative surgery. PTEN expression may be used as a prognostic marker for patients with resected AA.

Aberrant expression of p53, p21, cyclin D1, and Bcl2 and their clinicopathological correlation in ampullary adenocarcinoma ☆

Previous studies on the molecular alterations in ampullary adenocarcinoma (AA) are limited, and little is known about their clinical implications. The objective of this study is to examine the expression of p53, p21, cyclin D1, and Bcl2 and their clinical significance in patients with AA. Tissue microarrays were constructed using archival tissue from 92 patients with AA who underwent pancreaticoduodenectomy at our institution. Each tumor was sampled in triplicate with a 1.0-mm punch from representative areas. The expression of p53, p21, cyclin D1, and Bcl2 was evaluated by immunohistochemistry, and the staining results were correlated with clinicopathological features and survival. Among 92 cases studied, overexpression of p53, p21, cyclin D1, and Bcl2 was observed in 58.7%, 39.2%, 71.7%, and 5.4% of tumors, respectively. Patients whose tumor showed high level of cyclin D1 expression had higher risk of disease recurrence (P = .02) and worse recurrence-free and overall survivals after pancreaticoduodenectomy than did those with no or low cyclin D1 expression (P = .027 and P = .02, respectively). In multivariate analysis, cyclin D1 expression was an independent prognostic factor for both recurrence-free and overall survival (P < .05). However, there was no significant correlation between p53, p21, or Bcl2 expression and survival (P > .05). Our study showed that p53, p21, and cyclin D1, but not Bcl2, are frequently overexpressed in AAs. Cyclin D1 overexpression is associated with increased risk of disease recurrence and worse survival in patients with AA after resection.

KDR Mutation as a Novel Predictive Biomarker of Exceptional Response to Regorafenib in Metastatic Colorectal Cancer.

This is the case of an 84-year-old woman diagnosed with Stage IVb colon adenocarcinoma (CRC) metastatic to the liver, retroperitoneum, anastomotic site, and distal rectal sigmoid colon. She experienced intolerable side effects to systemic chemotherapy with 5-fluorouracil and bevacizumab, as well as disease progression. Next generation sequencing of her tumor was ordered, and further discussion of her malignancy’s genomic information took place at a multidisciplinary molecular tumor board. The patient had mutations in KRAS (Kirsten rat sarcoma viral oncogene homolog) which made her ineligible for epidermal growth factor receptor (EGFR) inhibitors; however, a KDR p.R961W c.2881C>T mutation was noted as a variant of unknown significance (VUS). KDR (kinase insert domain receptor) is the human gene encoding for vascular endothelial growth factor receptor 2 (VEGFR-2). She was then considered a suitable candidate for regorafenib, which she could only tolerate at a low dose of 40 mg daily, with the intent of prolonging her survival and to optimize her quality of life. We report her excellent tolerance and exceptional response to low dose regorafenib, including symptomatic, tumor marker, and sustained partial metabolic radiological improvement. In the largest Phase III trial of regorafenib in CRC, only five patients (1%) of 760 experienced a partial response (versus one patient, 0.4%, receiving placebo). KDR R961W mutation has been described but no functional data has been reported. This mutation occurs in the tyrosine kinase domain of the VEGFR-2. Regorafenib targets VEGFR-2 (KDR). Hereby we hypothesize KDR mutation as a novel predictive biomarker to exceptional response to regorafenib in metastatic colorectal cancer. To our knowledge, this is the first reported case of the potential correlation between KDR mutation and regorafenib use for the successful management of a patient with advanced CRC, leading to what is considered an exceptional response. Further studies based on this preliminary data are warranted.

Malignant mixed müllerian tumor of primary peritoneal origin

The aim of this study was to describe 2 cases of primary peritoneal malignant mixed müllerian tumor (MMMT). Two patients with primary peritoneal MMMT were examined for their clinical and pathologic features. We describe 2 cases of primary peritoneal MMMT in which the carcinomatous and mesenchymal components were readily identifiable, predominantly involving the peritoneum, with no ovarian involvement. The peritoneum and ovaries, with their common embryologic origin, likely account for the peritoneums ability to undergo a similar malignant transformation, with the resultant genesis of an MMMT of peritoneal origin.

Aldolase mRNA expression in endometrial cancer and the role of clotrimazole in endometrial cancer cell viability and morphology

Sir: Endometrial cancer (EC) is the most common gynecologic malignancy in developed countries. Recently, glycolytic enzymes have gained considerable attention in human cancers where glucose is the primary source of energy, and a high rate of glycolysis, which is the hallmark of cancer cells, provides the tumor with metabolic and survival advantages. Aldolase is an enzyme that is critical for the glycolytic pathway. Furthermore, an increased aldolase expression was found in various tumor types including cervical, endometrial, kidney, lung cancers and most recently in EC. An important regulator of glycolysis, namely clotrimazole (antifungal azole and calmodulin antagonist), was found to manipulate the binding of glycolytic enzymes to the cytoskeleton, which in turn modulates cell function, proliferation and differentiation. Herein, we evaluated cases of EC for aldolase mRNA expression and the effect of clotrimazole on EC cell lines. RNA was extracted from 70 patients with the diagnosis of endometrial adenocarcinoma. The expression of aldolaseC was determined using Taqman. qRTPCR gene expression Assay On Demand Probe ⁄ Primers (Applied Biosystems, Foster City, CA), with housekeeping gene GAPDH as an endogenous control. Samples were run, with three replicate assays for each gene in each sample. For each assay, the average GAPDH Ct (Cycle threshold) value in the TaqMan qPCR assay was subtracted from the Ct aldolaseC to obtain a DCt value (aldolaseC – GAPDH). Endometrial cancer cell lines including HEC1 and RL95 and colon cancer cell line (CT-26) (chosen as a control) were purchased from the American Tissue Culture Collection (ATCC, Manassas, VA) and they were cultivated according to the supplier’s recommendations. The cells were incubated in 5% CO2 at 37C in PBS containing 5 mM glucose in the absence and presence of 50uM clotrimazole (Sigma, St-Louis, Missouri). Clotrimazole was added to the cultures at different time points (1 h, 4 h, 8 h, 12 h, 18 h and 24 h). Untreated and clotrimazole treated cells were done in triplicate and washed one time with PBS and then harvested with trypsin. The cells were counted in a hemocytometer. Cell viability was determined by trypan blue dye exclusion. Transmission electron microscopy was done on the treated ⁄ and non-treated cells as described previously. For each assay, the average GAPDH Ct (Cycle threshold) value in the TaqMan qPCR assay was subtracted from the Ct of Aldolase to obtain a delta Ct value (Aldolase – GAPDH). Linear regression analyses were used to examine the association between the aldolaseC qRT-PCR levels and the patients’ clinicopathologic characteristics. Cox regression analyses were used to examine the relation of aldolaseC expression on survival. All statistical analysis was performed using the computing environment R (http://www.r-project.org/). The clinical and pathology data of the 70 patients with the qRT-PCR measurement are summarized in Table 1. High aldolaseC mRNA levels were positively associated with high nuclear and FIGO grades (P = 0.0566 each). Aldolase mRNA levels were not associated with tumor subtypes (P = 0.1057). We found that aldolaseC overexpression showed a potential predictive value for shorter overall survival. However, statistical significance threshold was not reached (P = 0.285), probably due to the relatively small sample size (70 in total). We found no evidence that aldolaseC mRNA levels to be associated with other patient outcomes such as recurrence. HEC1 and CT26 were successfully treated with clotrimazole resulting in detachment of cancer cells from the culture plates. Tryptan blue dye showed that clotrimazole induced time-dependent reduction in cell viability in CT26 cell line and HEC1 cell lines (Figure 1). Treatment of cells with clotrimazole affected the morphology of the cells as seen with examination by TEM. These same cells at the 4 h time point showed a greatly enlarged and highly vacuolated subcellular compartment and enlarged and swollen mitochondria with loss of cristae (Figure 2C–D). At the 24 h time point, cell death has occurred, which was evidenced by loss of integrity of the plasma membrane which resulted in cell rupture (Figure 2E,F). Our work showed that aldolaseC was overexpressed in a subset of human samples and in endometrial cancer cell lines. The overexpression of aldolaseC by tumor cells is an indication that human endometrial cancer, like other tumor types, depends on glycolysis for its energy supply to ensure its survival. Binding glycolytic enzymes to the cytoskeleton provides local ATP and it also affects cell structure which has led to the hypothesis that inhibition of glycolysis may severely abolish ATP generation in cancer cells leading to their death. Clotrimazole is an antifungal azole derivate that has been recognized as a calmodulin antagonist which induces inhibition of cell proliferation. Recent studies on melanoma, lung, and colon cancer cell lines showed that clotrimazole induces a significant dose-and time dependent reduction in aldolase levels, ATP and cell viability. Our Correspondence 1015

Massive gastric juvenile-type polyposis: a clinicopathological analysis of 22 cases

Massive gastric polyposis is a rare entity that is often associated with juvenile polyposis syndrome (JPS). The aim of this study was to evaluate the clinicopathological features of 22 patients with abundant gastric juvenile‐type or hyperplastic‐like polyps.

Iatrogenic Kaposi’s Sarcoma in an HIV-Negative Young Male With Crohn’s Disease and IgA Nephropathy: A Case Report and Brief Review of the Literature:

Background. Kaposi’s sarcoma (KS) is a vascular tumor arising in association with human herpesvirus–8 (HHV-8) infection, and different variants show different clinical presentations. Isolated intestinal KS in the background of Crohn’s disease (CD) is exceedingly rare with only 3 cases reported in the English literature (from 1966 to 2016). Case Presentation. Herein, we report a case of intestinal KS in a 21-year-old HIV-negative Ethiopian male with a long-standing history of steroid therapy for his underlying IgA nephropathy. Recent gastrointestinal biopsies confirmed an additional diagnosis of CD. Despite the addition of Infliximab to his therapy, his CD remained refractory, and a laparoscopic-assisted ileocolectomy was performed to alleviate a partial small bowel obstruction. Examination of his terminal ileum demonstrated a polypoid mass with adjacent incidental ileal submucosal nodules. These nodules were composed of plump spindle cells with scattered mitoses and vascular channels with extravasated red blood cells. Intratumoral hyaline globules were also noted. Immunohistochemistry revealed HHV-8 positivity, confirming the histologic impression of KS. Conclusions. Here we report the fourth case of KS in CD in an HIV-negative patient and only the third case of isolated intestinal KS in the setting of CD. A review of the literature suggests that attenuation of immunosuppressive therapy may be adequate management of iatrogenic KS in the absence of a systemic HHV-8 infection.