Cytogenetic Profile of Unknown Primary Tumors: Clues for Their Pathogenesis and Clinical Management

Unknown primary tumors (UPTs) represent an entity of great clinical and biological interest, whose origin cannot be determined even after medical workup. To better understand their pathogenesis by outlining their genetic composition, 20 UPTs were investigated by G-banding, supplemented with Fluorescence In Situ Hybridization and Comparative Genomic Hybridization analyses. The data obtained were sufficient to reach a diagnosis in five cases — four lymphomas and one Ewing sarcoma — demonstrating that in a subset of UPTs, cytogenetics can be an adjunct for differential diagnosis. In the remaining 15 UPTs, an aggressive cytogenetic pattern was revealed. The most frequently rearranged chromosome regions were 1q21, 3p13, 6q15-23, 7q22, 11p12-5, and 11q14-24, pinpointing gene loci probably associated with the peculiar pathogenesis of UPTs. The preferential involvement of 4q31, 6q15, 10q25, and 13q22 in adenocarcinomas (whereas 11q22 is involved in the rest of the carcinomas) — in addition to the marked divergence in the mean average of chromosomal changes, 16 and 3, respectively — demonstrates genotypic differences between the two histologic subgroups. Furthermore, the significantly shorter survival in cases displaying massive chromosome changes compared with those having a few changes indicates that the cytogenetic pattern might be used as a tool to assess prognosis in UPTs, even without the detection of their primary site

Successful en bloc resection of primary hepatocellular carcinoma directly invading the stomach and pancreas

Multivisceral surgical resection for cure was successfully performed in a 70-year-old man suffering from a primary hepatocellular carcinoma (HCC) associated with direct invasion to the stomach and pancreas. The patient presented with gastric outlet obstruction, upper abdominal pain and a history of chronic liver disease due to hepatitis B virus (HBV) infection. Upper gastrointestinal (GI) endoscopy revealed an infiltrating tumor protruding through the gastric wall and obliterating the lumen. Computer tomograghy (CT) and magnetic resonance imaging (MRI) scan demonstrated a 15-cm tumor in the left lateral segment of the liver with invasion to the stomach and pancreas. Alpha-foetoprotein (AFP) levels and liver function tests were normal. The patient underwent an en bloc left hepatectomy, total gastrectomy, distal pancreatectomy with splenectomy and radical lymphadenectomy. Pathology revealed a poorly differentiated, giant cell HCC involving the stomach and pancreas. Disease-free margins of resection were achieved. The patient’s postoperative course was uneventful. Sixteen months after surgery, he has no recurrence or distal metastasis. Direct invasion of HCC into the GI tract is rarely encountered. Complete surgical resection should be considered in selected patients with an appropriate hepatic functional reserve

Clinicopathologic characteristics of triple-negative breast cancer and relationship to basal markers

e11519 Background: Triple negative breast cancers are immunohistochemical surrogates of basal-like breast cancers. There is no complete overlap between triple negative and basal-like tumors and as gene expression studies evolve, further subclassification bearing clinical relevance is underway. Our purpose was to correlate clinicopathologic characteristics of triple negative breast cancer tumors with expression of basal markers in an effort to define immunohistochemically subgroups of this heterogenous disease Methods: Data were retrieved and analysed using our electronic databank. Patient samples were reviewed by an expert breast cancer pathologist and stained additionally for EGFR and CK 5/6 antibodies. Results: Sixty-five women with triple negative breast cancer were identified. Mean age was 58.3±12.9 years. Most tumors (86%) were of ductal histology, 53% grade 3, 48% having high Ki-67 index (>14%). 10% of patients presented with Stage IV, 25% with Stage III, 38% with stage II and 27% with stage I disease. 63% of patients were postmenopausal. EGFR staining was present in 43% of tumor samples, whereas CK 5/6 in 38.5%. Both EGFR and CK 5/6 expression was found in 18.5%, whereas 37% of tumors expressed neither EGFR or CK 5/6. No difference was observed between tumors expressing any of these 2 basal markers as compared to EGFR and CK 5/6 negative tumors in terms of Ki-67 index, grade, tumor size and nodal involvement. Lymphovascular invasion and non-ductal histology tended to occur more frequently (p=ns) in non-basal tumors. Additionally, patients with expression of any of the basal markers tended to be more obese than the non-basal triple negative breast cancer patients (p=ns). Conclusions: Further immunohistochemical markers apart from EGFR and CK 5/6 are needed in order to further define clinically meaningful subgroups of triple negative breast cancer