Pathology Residents Comprise Inspection Team for a CAP Self-Inspection

We report our experience at the University of Florida in which residents and fellows served as the inspection team for a College of American Pathologists (CAP) self-inspection. We aimed to determine whether the CAP self-inspection could serve as a learning opportunity for pathology residents and fellows. To prepare for the inspection, we provided a series of 4 lunchtime seminars covering numerous laboratory management topics relating to inspections and laboratory quality. Preparation for the inspection began approximately 4 months prior to the date of the inspection. The intent was to simulate a CAP peer inspection, with the exception that the date was announced. The associate residency program director served as the team leader. All residents and fellows completed inspector training provided by CAP, and the team leader completed the team leader training. A 20 question pre- and posttest was administered; additionally, an anonymous survey was given after the inspection. The residents’ and fellows’ posttest scores were an average of 15% higher than on the pretest ( P < .01). The surveys as well as subjective comments were overwhelmingly positive. In conclusion, the resident’s and fellow’s experience as an inspector during a CAP self-inspection was a useful tool to learn accreditation and laboratory management

Duodenal gangliocytic paraganglioma: A case report and literature review

Introduction: Gangliocytic paraganglioma is a rare tumor that is most commonly located in the duodenum. At presentation, it may be confused with a gastrointestinal stromal tumor (GIST), but distinguishing between these tumors is critical because the natural history and treatment of these two tumors differs markedly. Duodenal gangliocytic paraganglioma typically exhibits benign behavior with occasional regional lymph node metastasis and no reports of tumor associated deaths. Recurrence after resection is rare. Presentation of case: A 50 year-old male presented with melena and hemoglobin concentration of 4.6 g/dl. Esophagogastroduodenoscopy demonstrated a submucosal mass in the third portion of the duodenum with no active bleeding. CT scan identified no regional lymphadenopathy or distant metastasis. The tumor was resected through a longitudinal duodenotomy with negative margins. Discussion: Endoscopic resection of duodenal gangliocytic paraganglioma appears to be safe and effective when tumor may be removed in its entirety by this method. If the tumor is not suspended by a stalk or there is suspicion for regional lymph node disease then surgical management is preferred. Radiation oncologists at high volume centers have endorsed utilization of adjuvant radiotherapy to the postsurgical bed in cases involving lymph node metastasis. Utilization of chemotherapy for management of this disease has not been reported. Conclusion: Localized duodenal gangliocytic paragangliomas are best managed by resection with negative margins. In cases in which the tumor is resected with negative margins, it appears to be safe to embark on a course of surveillance and forego adjuvant therapy

Gastric Plexiform Fibromyxoma: A Great Mimic of Gastrointestinal Stromal Tumor (GIST) and Diagnostic Pitfalls.

Through a multicenter study, we collected seven cases of gastric plexiform fibromyxoma including four females and three males, 21 to 79 y old (46.1&nbsp;±&nbsp;10.1). All cases showed a unilocular lesion measuring 0.3 to 17 cm (5.3&nbsp;±&nbsp;2.4), arising from antrum (5/7) or body (2/7). Six of the seven cases had intraoperative frozen sections and/or endoscopic ultrasound fine needle aspiration (EUS-FNA), and all of them were preoperatively or intraoperatively diagnosed as gastrointestinal stromal tumor (GIST). EUS-FNA material showed markedly elongated spindle cells with streaming oval to elongated nuclei with rounded ends. Histologically, the tumors exhibited a plexiform growth pattern and were composed of a rich myxoid stroma and cytologically bland uniform spindle cells without mitotic figures, with the exception of one case which displayed nuclear pleomorphism and increased mitosis. Immunostains showed the tumor cells to be focally positive for SMA (6/6), focally and weakly positive for desmin (3/6) and caldesmon (2/3), negative for CD117 (0/7), CD34 (0/7), DOG1 (0/4), and S100 (0/5). No mutations were identified on Next-Generation Sequencing test, and no loss of SDHB immunoreactivity was identified in the tumor with nuclear pleomorphism. One case was treated with Gleevec because of the initial diagnosis of GIST. All patients had a follow-up for up to 11&nbsp;y, with no tumor recurrence or metastasis reported. Our results suggest that gastric plexiform fibromyxoma is rare and may be underrecognized and misinterpreted as GIST during intraoperative frozen section or preoperative EUS-FNA diagnosis without immunostains leading to inappropriate treatment

Association of Suppressive Myeloid Cell Enrichment with Aggressive Oropharynx Squamous Cell Carcinoma

Background: While immune-cell infiltrated tumors, such as human papillomavirus positive (HPV+) ororpharyngeal squamous cell carcinomas (OPSCC) have been associated with an improved clinical prognosis, there is evidence to suggest that OPSCCs are also subjected to increased immunoregulatory influence. The objective of this study was to assess whether patients with clinically aggressive OPSCC have a distinct immunosuppressive immune signature in the primary tumor. Methods: This retrospective case-control study analyzed 37 pre-treatment tissue samples from HPV+ and HPV-negative OPSCC patients treated at a single institution. The cases were patients with known disease recurrence and the controls were patients without disease recurrence. An mRNA-expression immune-pathway profiling was performed, and correlated to clinical outcomes. The TCGA head and neck cancer database was utilized to make comparisons with the institutional cohort. Results: In our cohort, HPV-negative and HPV+ patients with known disease recurrence both had significantly increased suppressive monoctyte/macrophage and granulocyte cell-expression-profile enrichment. Similar findings were found in the TCGA cohort when comparing HPV-negative to positive patients. Conclusions: our study demonstrates that patients with recurrent HPV+ OPSCC had suppressive monocyte/macrophage and granulocyte immune-cell enrichment, similar to those seen in the more aggressive HPV-negative OPSCC

KR158 Spheres Harboring Slow-Cycling Cells Recapitulate High-Grade Glioma Features in an Immunocompetent System

Glioblastoma (GBM) poses a significant challenge in clinical oncology due to its aggressive nature, heterogeneity, and resistance to therapies. Cancer stem cells (CSCs) play a critical role in GBM, particularly in treatment resistance and tumor relapse, emphasizing the need to comprehend the mechanisms regulating these cells. Also, their multifaceted contributions to the tumor microenvironment (TME) underline their significance, driven by their unique properties. This study aimed to characterize glioblastoma stem cells (GSCs), specifically slow-cycling cells (SCCs), in an immunocompetent murine GBM model to explore their similarities with their human counterparts. Using the KR158 mouse model, we confirmed that SCCs isolated from this model exhibited key traits and functional properties akin to human SCCs. KR158 murine SCCs, expanded in the gliomasphere assay, demonstrated sphere forming ability, self-renewing capacity, positive tumorigenicity, enhanced stemness and resistance to chemotherapy. Together, our findings validate the KR158 murine model as a framework to investigate GSCs and SCCs in GBM pathology, and explore specifically the SCC–immune system communications, understand their role in disease progression, and evaluate the effect of therapeutic strategies targeting these specific connections

Low Frequency of Lymph Node Metastases in Patients in the United States With Early-stage Gastric Cancers That Fulfill Japanese Endoscopic Resection Criteria

In the West, early gastric cancer is increasingly managed with endoscopic resection (ER). This is, however, based on the assumption that the low prevalence and risk of lymph node metastases observed in Asian patients is applicable to patients in the United States. We sought to evaluate the frequency of and factors associated with metastasis of early gastric cancers to lymph nodes, and whether the Japanese ER criteria are applicable to patients in the US. We performed a retrospective study of 176 patients (mean age 68.5 years; 59.1% male; 58.5% white) who underwent surgical resection with lymph node dissection of T1 and Tis gastric adenocarcinomas, staged by pathologists, at 7 tertiary care centers in the US from January 1, 1999, through December 31, 2016. The frequency of lymph node metastases and associated risk factors were determined. The mean size of gastric adenocarcinomas was 23.0 ± 16.6 mm—most were located in the lower-third of the stomach (67.0%), invading the submucosa (55.1%), and moderately differentiated (31.3%). Lymphovascular invasion was observed in 18.2% of lesions. Overall, 20.5% of patients had lymph node metastases. Submucosal invasion (odds ratio, 3.9; 95% CI, 1.4–10.7) and lymphovascular invasion (odds ratio, 4.6; 95% CI, 1.8–12.0) were independently associated with increased risk of metastasis to lymph nodes. The frequency of lymph node metastases among patients fulfilling standard and expanded Japanese criteria for ER were 0 and 7.5%, respectively. The frequency of lymph node metastases among patients with early gastric cancer in a US population is higher than that of published Asian series. However, early gastric cancer lesions that meet the Japanese standard criteria for ER are associated with negligible risk of metastasis to lymph nodes, so ER can be recommended for definitive therapy. Expanded criteria cancers appear to have a higher risk of metastasis to lymph nodes, so ER may be considered for select cases