Squamous cell carcinoma of the colon with an elevated serum squamous cell carcinoma antigen responding to combination chemotherapy

Primary squamous cell colorectal carcinomas are uncommon, and their characteristics are not well known. They seem to occur most commonly in the fifth decade of life with a slight predominance for men. The most commonly reported anatomic locations are the rectum and the proximal colon. Clinical features and common diagnostic methods do not easily differentiate squamous cell colorectal carcinomas from adenocarcinomas. Because of their extremely rare occurrence, it is difficult to study their natural course, clinical behavior, and response to therapy. This report presents the case of a pure squamous cell colorectal cancer and provides a brief review of the literature, which includes 60 previously published cases. The case of a patient with T3N2M0 primary squamous cell carcinoma of the rectosigmoid colon, which was initially treated with abdominoperineal resection followed by adjuvant chemotherapy and radiation, is presented. During the follow-up, an elevated squamous cell carcinoma antigen (SCC Ag) level led to restaging computed tomography scans, which confirmed recurrent metastatic disease in the liver. Response to chemotherapy with a decrease in tumor size correlated with a decrease in the serum SCC Ag level. Although SCC Ag has been used as a tumor marker for squamous cell cancers of the lung, head and neck, uterine cervix, and esophagus, this is the first reported case of a squamous cell colon carcinoma presenting with an elevated SCC Ag at the time of recurrence. In addition, this patient showed an objective partial response to combination chemotherapy, with a decrease in the serum level of this tumor marker.

Clinicopathologic differences between diploid and tetraploid complete hydatidiform moles

Complete hydatiform moles (CHM) may be are diploid or tetraploid. The proportions vary in the literature. To date, there has not been a systematic characterization of these two types. This study is a retrospective investigation of clinicopathologic differences between diploid and tetraploid CHMs. Thirteen formalin-fixed, paraffin-embedded CHMs were analyzed for DNA content by flow cytometry (FC). Using standard flow cytometric definitions, histograms were classified as FC-diploid or FC-tetraploid (4N peak > or = 15% of 2N peak and cell cycle events to 8N) and compared with respect to selected clinical and pathologic features. Eight CHMs (61%) met the criteria of tetraploidy by flow cytometry, although all five FC-diploid cases harbored minor (< 15%) tetraploid subpopulations. Patients with tetraploid moles were older (mean age 32.8 years vs. 19.6 years, p < 0.005), presented at lower preevacuation gestational ages (12.7 weeks vs. 15.4 weeks, p < 0.05), had higher mean serum beta-HCG levels (2.82 x 10(5) i.u. vs. 0.99 x 10(5) i.u., p = 0.07), and higher DNA S-phase fractions (17.9% vs. 7.0%, p = 0.002). No significant differences were found in other histological features. No moles recurred. In this small sample of CHMs, tetraploidy was common. Compared with the FC-diploid CHMs, FC-tetraploid CHMs occurred in older patients with lower gestational age, higher serum beta-HCG levels, and higher DNA S-phase fraction by flow cytometry.