Giris ve Amaç:Medüller karsinomlar, tüm kolorektal kanserlerin %1?inden azini olusturan, histolojik olarak genis eozinofilik sitoplazmali, veziküler nükleuslu ve belirgin nükleollü hücrelerle karakterli glandüler diferansiyasyonun gözlenmedigi, solid büyüme paternine sahip nadir tümörler olup, yüksek mikrosatellit instabilite ve Lynch sendromu ile olan iliskisi nedeniyle önemli antitelerdir. Çalismamizda medüller karsinom olgularinin klinikopatolojik özellikleri arastirilmistir. Gereç ve Yöntem: Kolorektal rezeksiyon materyalleri 2002-2011 yillari arasinda degerlendirilen ve odaksal olarak solid büyüme paternine sahip alanlari bulunan 50 az diferansiye adenokarsinom olgusu, 2010 Dünya Saglik Örgütü siniflamasinda tanimlanan kriterlere göre geriye dönük olarak yeniden degerlendirilmis, evrelendirilmis ve medüller karsinom olasili-gi açisindan arastirilmistir. Bulgular az diferansiye adenokarsinomlarda izlenen bulgular ile nonparametrik testlerle karsilastirilmistir. Bulgular: Yedi olgu medüller karsinom olarak degerlendirilmis olup incelenen dönemde degerlendirilen 1128 olgu içerisindeki orani %0,62?dir. Olgularin üçü kadin, yas ortalamasi 62±5,9?dur (Dagilim:41-80). Tümörler sag kolon yerlesimli (5/7) ve ekspansif büyüme paternine sahip olup (6/7), belirgin Crohn-benzeri lenfoid reaksiyon (5/7) ve tümörü infiltre eden lenfositler (7/7) göstermektedir. Az diferansiye adenokarsinom olarak siniflanan 43 olgu ile karsilastirildiginda lenfovasküler invazyon (%28?e karsilik %39,5), pT4 (%14,3?e karsilik %20,9) ve pN2 tümör oraninin (%14,3?e karsilik %30,2) daha düsük oldugu; perinöral invazyon, tümör ?tomurcuklanmasi? ve ?kirli nekroz?un ise hiç olmadigi (p=0,002, ki-kare) dikkati çekmistir.Sonuç: Medüller karsinomlar, siklikla sag kolon yerlesimli, ekspansif büyüyen, göreceli olarak daha erken evrede izlenen ancak özel histolojik görünümleri ve ayirici tani güçlükleri nedeniyle üzerinde durulmasi gereken tümörlerdir. Serimizde izlenen bulgularin literatürle uyumlu oldugu görülmüstür. Çalisma, bu az görülen ancak Lynch sendromu ile iliskisi gibi önemli klinik yansimalari olabilecek antiteye klinik duyarliligin artirilmasi amaciyla sunulmustur.
Background and Aims: Medullary carcinomas are rare tumors, constituting less than 1% of all colorectal cancers, characterized with nongland-forming, solid sheets of malignant cells with vesicular nuclei, prominent nucleoli and abundant pink cytoplasm. They are important tumors due to their relationship with high microsatellite instability and Lynch syndrome. We reviewed the clinicopathological features of medullary carcinomas. Materials and Methods:The resection specimens of 50 poorly differentiated adenocarcinomas, examined between 2002-2011 and showing at least focal areas with a solid growth pattern, were retrospectively reviewed, re-classified, and re-staged according to the World Health Organization 2010 classification for features of medullary carcinoma. The clinicopathological findings were compared statistically with poorly differentiated adenocarcinomas using nonparametric tests.Results: Seven cases were reclassified as medullary carcinoma, constituting 0.62% of 1128 colorectal tumors diagnosed using their resection specimens within the given period. Three of the cases were female, and the mean age was 62± 5.9 years (range: 41-80 years). Tumors were located in right colon (5/7), showed expansive growth pattern (6/7), prominent Crohn?s-like lymphoid reaction (5/7), and tumor-infiltrating lymphocytes (7/7). When compared with 43 poorly differentiated adenocarcinoma cases, the lower incidence of lymphovascular invasion (28% versus 39.5%), pT4 (14.3% versus 20.9%) and pN2 tumors (14.3% versus 30.2%) and absence of perineural invasion, tumor ?budding? and ?dirty necrosis? (p=0.002, chisquare) were noteworthy. Conclusions:Medullary carcinomas are rare tumors located predominantly in the right colon, showing an expansive growth pattern, and respectively, lower tumor and lymph node stages. They deserve special attention due to their special histological features and differential diagnostic pitfalls. The clinicopathological findings in our series are consistent with the previous literature. This study is presented to draw attention to this rare but important entity, which may have significant clinical implications in view of its relationship with Lynch syndrome.