Gastric cancer in the remnant stomach after pancreaticoduodenectomy: A case series.

BACKGROUND: Gastric cancer (GC) occasionally develops in the remnant stomach following pancreaticoduodenectomy (PD). In those who have undergone PD for adenocarcinoma, however, the interval and frequency of anastomotic GC are unknown. METHODS: We searched our institutional database for patients who had undergone PD for adenocarcinoma and subsequently developed GC between 1994 and 2018 and found six patients. We summarized the clinicopathologic features and prognosis of these patients with anastomotic GC. RESULTS: The median interval from PD to development of GC was 111.5 months. Four patients underwent curative resection of gastrojejunal anastomosis. Pathologic analysis showed signet ring cell carcinoma in four patients. The median overall survival after developing GC was 61 months. CONCLUSION: Our findings indicate that GC in the remnant stomach after PD is rare but can occur at gastrojejunostomy anastomosis after a prolonged period. Periodic and long-term follow-up +/- surveillance endoscopy to facilitate early detection of GC in the remnant stomach is recommended, particularly for symptomatic patients. Recognition of the anastomotic tumor as a second primary and not a pancreatic ductal adenocarcinoma recurrence/metastasis is crucial in the optimal treatment of these patients, as curative resection of early-stage GC may prolong survival.

Loss of Menin Expression by Immunohistochemistry in Pancreatic Neuroendocrine Tumors: Comparison Between Primary and Metastatic Tumors.

OBJECTIVES: Molecular characterization of sporadic pancreatic neuroendocrine tumors (PanNETs) demonstrates frequent alterations in MEN1. As the role of menin immunohistochemistry as a potential biomarker is being developed, knowledge of whether the pattern of menin expression is the same in primary tumors and distant metastases may help in patient care. Therefore, we compared patterns of menin expression in matched primary tumors and metastases. METHODS: We evaluated loss of menin nuclear expression by immunohistochemistry in 44 matched samples of primary and metastatic PanNETs and concordance in staining pattern between primary and metastatic tumors. RESULTS: Menin nuclear expression was lost in 18 (41%) of 44 primary tumors and 17 (39%) of 44 metastases. Concordant loss of menin expression was observed in 41 cases (93%); discordance was observed in 3 cases (7%; 95% confidence interval, 1.4%-18.7%), including 2 with loss in the primary tumor but not the metastasis. CONCLUSIONS: The concordance of menin staining between primary tumor and metastasis in most cases suggests that menin loss is an early event in PanNET tumorigenesis. The discordant expression observed in a small subset may be a source of menin-directed therapy failure; thus, repeat assessment of metastases may be helpful for treatment selection.

Index report of cutaneous angiosarcomas with strong positivity for tyrosinase mimicking melanoma with further evaluation of melanocytic markers in a large angiosarcoma series.

Cutaneous angiosarcoma can be challenging to diagnose particularly when poorly vasoformative and studied on biopsies. We report a case of a cutaneous angiosarcoma with strong positivity for tyrosinase, the first to our knowledge, initially misdiagnosed as melanoma. We subsequently evaluated the reactivity of panmelanocytic cocktail (tyrosinase, HMB-45 and Melan-A), SOX10, tyrosinase and MITF in a large tissue microarray (TMA) of angiosarcoma. The TMA included 142 cases of angiosarcomas (29 cutaneous, 22 primary breast, 41 post-radiation breast, 15 visceral, 26 deep soft tissue and bone, 5 chronic lymphedema-associated and 4 angiosarcomas arising in other sarcomas). Immunohistochemical studies were performed with anti-panmelanocytic cocktail, anti-SOX10, anti-MITF and anti-tyrosinase antibodies. TMA staining results were scored on intensity and percentage of tumoral labeling. Aside from the index case, no cases (0 of 133) showed positivity for tyrosinase including 28 cutaneous angiosarcomas. One breast angiosarcoma (1 of 131) was positive for MITF. All cases were negative for SOX10 and panmelanocytic cocktail (0 of 132). Angiosarcomas can rarely be positive for tyrosinase and MITF. Pathologists should be cognizant of these rare exceptions to prevent confusion with melanoma. Additional immunohistochemical markers for vascular and melanocytic differentiation, thorough histological examination for vasoformative and in situ areas as well as clinical impression are helpful in these exceptionally problematic cases.

EBV-associated lymphoepithelioma-like carcinoma of the pancreas: Case report with targeted sequencing analysis.

Lymphoepithelioma-like carcinomas are distinctive epithelial derived malignant neoplasms that have a syncytial growth pattern and lymphoid stroma. The majority of tumors with this appearance are Epstein Barr virus (EBV)-associated. We report a patient with a clinical presentation concerning for lymphoma who was diagnosed with an EBV-associated pancreatic carcinoma with a lymphoepithelioma-like pattern. Targeted sequencing analysis showed a molecular profile distinct from conventional ductal adenocarcinoma of the pancreas.