doi: 10.5146/tjpath.2013.01164 Olgu Sunumu/Case Report 134 (Turk Patoloji Derg 2013, 29:134-137) Received : 22.02.2012 Accepted : 19.04.2012 Signet Ring Lobular Carcinoma in Situ as a Part of the “Rosen Triad” (Tubular Carcinoma, Columnar Cell Hyperplasia, and Lobular Carcinoma in Situ) Rosen Triadı’ nın (Tübüler Karsinom, Kolumnar Hücre Hiperplazi ve Lobüler Karsinoma in Situ) Bir Parçası Olarak Taşlı Yüzük Lobüler Karsinoma in Situ Josko BEZIC, Dijana GUGIC Clinical Hospital Split, Institute of Pathology, Split, CROATIA Correspondence: Josko BEZİC Clinical Hospital Split, Institute of Pathology, Split, CROATIA E-mail: jbezic@mefst.hr Phone: +38 521 556 512 ABSTRACT Objective: he association of tubular carcinoma, columnar cell lesions and lobular carcinoma in situ, also known as the “Rosen Triad”, may be encountered in breast biopsies performed for evaluation of mammographically detected microcalcifications. Case Report: A case in which tubular carcinoma and columnar cell hyperplasia were associated with a histologically unusual form of signet ring lobular carcinoma in situ is presented. Signet ring non-invasive lobular carcinoma is classified as high-grade lobular carcinoma in situ, but herein is associated with changes that belong to the molecular pathway of low-grade mammary neoplasia. Conclusion: We reported the case of lobular carcinoma in situ associated with columnar cell hyperplasia and tubular carcinoma, in which the lobular carcinoma in situ was presented in a histologically unexpected form comprised predominantly of signet ring cells. Key Words: Breast, Carcinoma, Signet ring cell, Carcinoma in situ ÖZ Amaç: “Rosen Triadı” olarak da bilinen tübüler karsinom, kolumnar hücre lezyonları ve lobüler karsinoma in situ birlikteliği, mamografik olarak saptanmış mikrokalsifikasyonların değerlendirilmesi için yapılan meme biopsilerinde görülebilir. Olgu Sunumu: Tübüler karsinom ve kolumnar hücre hiperplazisi ile ilişkili, histolojik olarak olağan dışı bir taşlı yüzük lobüler karsinoma in situ vakası sunulmaktadır. Taşlı yüzük noninvaziv lobüler karsinom, yüksek dereceli lobüler karsinoma in situ olarak sınılandırılmaktadır ancak burada düşük dereceli meme neoplazisinin moleküler yolağına ait değişikliklerle ilişkilidir. Sonuç: Kolumnar hücre hiperplazisi ve tübüler karsinom ile ilişkili, histolojik olarak beklenmeyen bir şekilde baskın olarak taşlı yüzük hücrelerinden oluşan, bir lobüler karsinoma in situ vakası sunduk. Anahtar Sözcükler: Meme, Karsinom, Taşlı yüzük hücreli, Karsinoma in situ INTRODUCTION he widespread use of mammographic screening has called attention to columnar cell lesions, a histological inding commonly encountered in breast biopsies performed for evaluation of detected microcalciications. Columnar cell lesions are histologically characterized by dilated terminal duct lobular units lined by epithelium showing columnar cell morphology, ranging from one or two layers of benign epithelium to stratiied epithelium with or without atypia (1,2). In the past, many investigators recognized these morphological changes under a variety of terms. Nowadays a practical classiication system, which divides columnar cell lesions in three broad categories as columnar cell change (CCC), columnar cell hyperplasia (CCH), and columnar cell change/hyperplasia with cytological atypia has been adopted. he World Health Organization has proposed the term lat epithelial atypia (FEA) for columnar cell change/ hyperplasia with atypia, with alternative designation of ductal intraepithelial neoplasia grade 1A (DIN 1A) (1,3). Rosen irst observed frequent histological coexistence of tubular carcinoma (TC) and CCH, with occasional association of lobular carcinoma in situ (LCIS) (4). he histological triad of TC, columnar cell lesions and LCIS is also known as the “Rosen Triad”. Here we portray a case of “Rosen Triad” in which TC is associated with CCH and signet ring LCIS.