Characterization of leiomyomatoid angiomatous neuroendocrine tumour (LANT)-like tumour of the myometrium with histopathological examination.

Takuma Hayashi

Volume : V, Issue : XII, December - 2016

Characterization of leiomyomatoid angiomatous neuroendocrine tumour (LANT)-like tumour of the myometrium with histopathological examination.

Takuma Hayashi

Abstract :

Leiomyomatoid angiomatous neuroendocrine tumour (LANT) is a possible new disease entity that was described as a dimorphic neurosecretory tumour with a leiomyomatous vascular component; it was found in the pituitary. We describe here uterine LANT-like tumour in a 45-year-old woman with uterine mesenchymal tumour, diagnosed clinically as uterine leiomyoma. She underwent laparoscopic myomectomy. The tumour consisted of hyalinized vasculature, containing factor VIII-positive endothelium and smooth muscle actin-positive vascular smooth muscle cells, and stromal cells, expressing neuroadhesion molecules. Both vascular and stromal components diffusely expressed chromogranin A. Histopathological examinations of uterine LANT-like tumour revealed the common characteristic abnormalities of uterine mesenchymal malignant tumours, i.e. leiomyosarcomas. Our research findings show that defective expression of CALPONIN h1 and proteasome beta 9 (PSMB9)/b1i is observed in uterine LANT-like tumour such like immune-pathological findings of uterine leiomyosarcoma. These findings meet the definition of uterine LANT-like tumour, and the occurrence of our case suggests that LANT is a special type of neuroendocrine neoplasm and is not organ specific.