Unexpected placental tumor: A case report

Placental non-trophoblastic tumors (PNTT) are uncommon, consisting mainly of chorangiomas, placental teratomas (PT) and haemangiomas. PT are exceedingly rare, with less than 40 cases reported in the literature. We, herein, present a case of mature PT arising within the membranes, and we aim to discuss the clinico-pathological characteristics of this rare entity.

A 30-year-old female patient, gravida 1, para 1, with no medical history, was admitted at 40 weeks' gestational age. Ultrasound in the third trimester of pregnancy revealed agenesis of the left fetal kidney and a fundal placenta with increased uterine artery resistance. A cesarean section was performed for failure of labor's induction. Gross examination of the placenta revealed a solid polypoid mass, measuring 4 × 2 cm, attached to the membranes and covered by a smooth cutaneous coating. The cut surface was soft, yellowish, and focally heterogenous, with areas of adipose tissue and cartilage. Microscopic examination revealed that the mass was made up of a mature keratinized squamous layer, with skin appendages, adipose and cartilaginous tissues. The diagnosis of PT was established.

PT are rarely suspected on prenatal ultrasonography and the diagnosis is made after delivery. Only pathological examination allows the diagnosis of certainty. Their histogenesis is still poorly understood.

We presented a rare case of mature PT arising within the membranes. PT are extremely uncommon tumors. Usually, they are benign, and no fetal or maternal complications. A better knowledge of these uncommon tumors is mandatory to not miss the diagnosis.