Adenocarcinoma arising in an extralobar sequestration: A case report and review of the literature

Extralobar sequestration is a type of bronchopulmonary foregut malformation defined as an isolated portion of lung tissue with a systemic arterial supply, its own pleural investment, and no bronchial communication. While it may be recognized in utero or in the neonatal period, depending on its location and associated anomalies, it can also go unrecognized until later in life when it may present as a mass. We report the first case of adenocarcinoma arising in an extralobar sequestration. The patient was a 70-year old man with a 55 pack year smoking history who presented with chest discomfort and was found to have a 6.5. cm right lower lobe mass. Percutaneous biopsy of the mass was positive for adenocarcinoma. At surgery, the mass was noted to have a separate arterial connection, no bronchial communication, and its own pleural investment, consistent with an extralobar sequestration. Malignancy arising in pulmonary sequestrations is rare and the few reported cases have been in intralobar types. Carcinoma arising in this setting adds to the dilemma of whether or not these developmental anomalies should be excised or followed. Our tumor, while small, did have vascular invasion. © 2014 Elsevier Ireland Ltd

Clinicopathologic Study of Calcifying Fibrous Tumor of the Gastrointestinal Tract: A Case Series.

Calcifying fibrous tumor (CFT) is a rare benign mesenchymal lesion known to arise at multiple body sites that may clinically mimic other more aggressive lesions in the gastrointestinal (GI) tract. In this study we describe the clinicopathologic findings of 28 GI tract CFTs. Tumors predominantly arose in middle-aged adults with a slight female predominance. The most commonly involved sites were small bowel and colon, followed by stomach and appendix. Tumors ranged from 0.3 to 9.3 cm (median 1.4 cm), and submucosa was the most commonly involved layer. All tumors were well circumscribed and unencapsulated. Microscopically, tumors were hypocellular and composed of spindle cells with abundant, haphazardly arranged hyalinized collagen. No necrosis and less than one mitosis per 10 HPF were identified in all cases. Calcification was present in most (81%) of the cases. All cases had lymphoplasmacytic inflammatory infiltrates either scattered throughout the lesion with occasional perivascular conglomeration or in the form of lymphoid aggregates. A lymphoplasmacytic cuff was usually present (81%). Immunostains showed variable CD34 immunoreactivity and variable numbers of IgG4-positive plasma cells. The lesional cells were negative for DOG-1, ALK-1, S100, C-kit, Sox10, Melan A, HMB45, desmin, CK7, and CK20, and showed cytoplasmic staining for β-catenin. Follow-up information was available in 5 cases with no recurrences reported to date (mean follow-up, 3 years). CFT is a rare benign tumor that can occur in part of the GI tract and should be distinguished from other mesenchymal tumors due to its low risk of recurrence

Mutational spectrum of intraepithelial neoplasia in pancreatic heterotopia

Heterotopic pancreatic parenchyma recapitulates the normal pancreas in extra-pancreatic locations and on rare occasions can even give rise to pancreatic adenocarcinoma. The genetic signatures of pancreatic adenocarcinoma and its precursor lesions are well characterized. We explored the genetic alterations in precursor lesions (intraductal papillary mucinous neoplasms [IPMN], pancreatic intraepithelial neoplasia [PanIN]) in patients with pancreatic heterotopias but without concomitant pancreatic ductal adenocarcinomas. This allowed us to determine whether the stereotypical dysplasia—infiltrating carcinoma sequence also occurs in these extra-pancreatic foci. Seven cases of heterotopic pancreas with ductal precursor lesions were identified. These included two IPMNs with focal high grade dysplasia and five PanINs with low to moderate grade dysplasia (PanIN grades 1–2). Neoplastic epithelium was micro-dissected and genomic DNA was extracted. Sequencing of commonly mutated hotspots (KRAS, TP53, CDKN2A, SMAD4, BRAF, and GNAS) in pancreatic ductal adenocarcinoma and its precursor lesions was performed. Both IPMNs were found to have KRAS codon 12 mutations. The identification of KRAS mutations suggests a genetic pathway shared with IPMN of the pancreas. No mutations were identified in our heterotopic PanINs. One of the possible mechanisms for the development of dysplasia in these lesions is field effect. At the time of these resections there was no clinical or pathologic evidence of a prior or concomitant pancreatic lesion. However, a clinically undetectable lesion is theoretically possible. Therefore, while a field effect cannot be excluded, there was no evidence for it in this study