{Reference Type}: Review
{Title}: Breast Carcinoma with a Special Histological Pattern of Sebaceous Differentiation and High-Frequency Microsatellite Instability: A Case Report and Review of the Literature.
{Author}: Luo L;Hu Y;Liu F;Yang J;Bai Y;Meng Y;Ding R;Hu M;Wu L;
{Journal}: Ann Clin Lab Sci
{Volume}: 52
{Issue}: 5
{Year}: Sep 2022
{Factor}: 1.18
{Abstract}: The World Health Organization in its 2019 Classification of Breast Tumors termed breast sebaceous carcinoma as invasive breast carcinoma of no special type (IBC-NST), with a sebaceous pattern. Approximately 30 cases of IBC-NST with a sebaceous pattern have been reported in the literature, and in all cases the expression of mismatch repair proteins in tumors was normal. Here, we report a case of IBC-NST with a sebaceous pattern and high-frequency microsatellite instability (MSI-H). This case was a sporadic sebaceous pattern of IBC-NST with MSI-H and was unrelated to Muir-Torre syndrome. Its histopathological characteristics were similar to those of MSI-H-associated triple-negative breast carcinoma (TNBC) with a high histological grade but were without tumor-infiltrating lymphocytes (TILs). The tumor did not recur after 20 months of follow-up.