[P-19] Endocervical fibroblastic malignant peripheral nerve sheath tumour (MPNST) in a young woman – a diagnostic challenge

Jithmal Meegoda1, Lalani De Silva1, Vidusha Ranathunga1, Harshima Wijesinghe1, Gayani Ranaweera1, Priyangi Pathirana2, Kanishka Karunaratne3 and Chandu De Silva1

  1. Department of Pathology, Faculty of Medicine, University of Colombo, Sri Lanka
  2. Department of Pathology, District General Hospital, Chilaw, Sri Lanka
  3. University Gynaecology and Obstetrics Unit, National Hospital of Sri Lanka

 

Background: Primary cervical sarcomas are extremely rare, representing < 1% of all cervical malignancies. Malignant peripheral nerve sheath tumours (MPNST) are rarer with only 17 reported cases. Here we report a 20-year-old female with endocervical MPNST, being the youngest in the literature.

Case Presentation: She presented with chronic urinary retention and lower abdominal pain. Radiology revealed a bicornuate uterus with a well-defined, mixed-echogenic endocervical mass measuring 10.7 x 9.6 x 9.4 cm. Initial incisional biopsy was compatible with a high-grade sarcoma and a debulking surgery was performed to preserve fertility. Histopathological examination revealed a malignant spindle cell tumour with hyper/hypocellular areas. The hypercellular areas showed long fascicles of spindle cells with a haemangiopericytomatous vascular pattern. The constituent cells contained enlarged, plump, pleomorphic nuclei with coarse chromatin. A myxoid stroma was noted in the hypocellular areas. There were frequent mitoses (20/mm2) and foci of geographic necrosis involving 30% of the tumour. Multiple foci of lymphovascular and perineural invasion were noted. The spindle cells were positive for S100 and CD34. The possibility of leiomyosarcoma, rhabdomyosarcoma, Ewing sarcoma, synovial sarcoma and carcinosarcoma were excluded by negative SMA, desmin, MyoD1, Bcl-2, CD-99, EMA and Pan-CK. She underwent radical hysterectomy, six months after the initial diagnosis which showed extensive tumour involving lower-uterine segment and right parametrium with single lymph node deposit. Currently she is being followed up at an oncology unit.

Discussion and Conclusion: Endocervical fibroblastic MPNST is different to other MPNST types since it is thought to arise from endocervical stromal fibroblasts. It is an aggressive malignancy with high recurrence rate, distant metastasis and poor response to chemoradiation.