Sang-Hyeob Kim§, Ae-Ri Ji§,
Jin-Kyu Park, Ah-Young Kim, Eun-Mi Lee, Eun-Joo Lee, Chang-Woo Min,
Kyung-Ku Kang, Myeong-Mi Lee, Soo-Eun Sung, Meeyul Hwang, Dong-Mi
Kwak, Tae-Hwan Kim and Kyu-Shik Jeong*
Department of Pathology, College of Veterinary
Medicine, Kyungpook National University, Daegu, Republic of Korea.
*Corresponding author: jeongks@knu.ac.kr
Abstract
Subcutaneous leiomyosarcoma is a malignant tumor
that originates from smooth muscles in the skin. Herein, we report a case of
subcutaneous leiomyosarcoma that occurred in the ear pinna of a 19-month-old
male Smad3+/- mouse. On gross examination, the mass extended to the
whole ear auricle and obscured the ear opening. The tumor was approximately
10x10 mm in size, ill-circumscribed, and firm with superficial hemorrhage. The
cut surface of the mass was grayish-white and solid with focal necrosis and
hemorrhage. Histologically, spindle tumor cells with cigar-like nuclei and plump
cells with round nuclei formed broad interlacing fascicles. Additionally, the
tumor cells invaded adjacent muscles. Immuno- histochemically, the tumor
sections had positive reactions for desmine and a-SMA and were partially
positive for vimentin while negative for S-100 and myogenin. Based on the
results of the examination, we diagnosed this case as subcutaneous
leiomyosarcoma.