PMC5511680_01
Leiomyosarcoma in mature cystic teratoma of ovary. (a) The cyst lined by keratinized squamous epithelium. Note the intramural sarcomatous component beneath the cyst lining (H&E, 1.25x). (b) Leiomyosarcoma showed intersecting fascicles of malignant spindle cells (H&E, 10x). (c) Leiomyosarcoma exhibited moderate to markedly atypical spindle cells with blunt-ended (or cigar-shaped) nuclei and eosinophilic fibrillar cytoplasm. Note numerous mitotic figures (H&E, 40x). (d) Leiomyosarcoma showed strong and diffuse positivity for smooth muscle actin (IHC stain, 40x).
CRIPA2017-7907359.001.jpg
PMC5511680_01_CRIPA2017-7907359.001.jpg
fig1
Microscopically, the cystic part showed a cutaneous lining composed of keratinized squamous epithelium (Figure 1(a)) with associated cutaneous appendages, associated with underneath mature fat tissue and cartilage, typical of a dermoid cyst. The neoplastic cells showed blunt-ended (cigar-shaped) nuclei with eosinophilic fibrillar cytoplasm (Figures 1(b) and 1(c)). Immunohistochemically, the malignant spindle component showed a diffusely positive reaction for smooth muscle actin (Figure 1(d)) and focal positivity for desmin and muscle-specific actin (HHF-35).
Leiomyosarcoma and squamous cell carcinoma. (a) Squamous cell carcinoma at the upper part of leiomyosarcoma. Note an abrupt demarcation between two components (H&E, 4x). (b) Squamous cell carcinoma was highlighted by positive staining for AE1/AE3, whereas leiomyosarcoma was completely negative (IHC stain, 4x). (c) Infiltrative nests of squamous cell carcinoma surrounded by desmoplastic stromal reaction (H&E, 10x).
CRIPA2017-7907359.002.jpg
PMC5511680_01_CRIPA2017-7907359.002.jpg
fig2
Nests of squamous cell carcinoma (13 mm in depth) infiltrated into the malignant spindle cell component, but both components were distinctive to each other, without a merging or transitional area of transformation from carcinoma into spindle cells (Figures 2(a) and 2(b)). The infiltrative carcinomatous component was focally surrounded by desmoplastic stroma (Figure 2(c)).