Obstetrics & Gynaecology Forum Volume 29 | Issue 2 | 2019

O&G Forum 2019; 29: 27 - 29 CASE REPORT Prognosis There is very little data to predict the prognosis for STUMPs, mainly because of varying diagnostic criteria and different terminology used. Overall survival rates of 92% at five years have been reported. 18 Age at diagnosis is not a poor prognostic factor, although one study did show that women diagnosed with recurrence after STUMP are younger than those with uneventful follow-up. 3 Most of these tumours have a benign clinical course. 18 Recurrence Recurrence can be local or metastatic and the tumour can recur as a STUMP or as leiomyosarcoma (10 – 25%). 1,2,3 Recurrence can be either early or late, with late recurrence occurring more than five years after initial diagnosis. 6 Uterine STUMPs usually have delayed recurrence, occurring years after initial diagnosis. 16 In some studies recurrence was reported to be between 8.7 and 11%, whereas in another retrospective study 40.7% (11 of 27 patients) had disease recurrence after a median follow up of 33.5 months. 1,2 Another study showed a recurrence rate of 11%, with more than half of them recurring as leiomyosarcoma and the average time to recurrence was 51 months. 6 The varying numbers in risk of recurrence are influenced by the diagnostic criteria for STUMPs. 6 The risk of recurrence does not appear to be influenced by the type of surgery and preservation of ovaries.1 However, laparoscopy and morcellation of leiyomyosarcoma is associated with peritoneal implants and thus may theoretically increase the risk of recurrence. 8 STUMPs have the highest median survival following recurrence, compared to other malignant uterine cancers. 16 P16 and p53 positive tumours are associated with a higher risk of recurrence, with p16 positive tumours experiencing earlier recurrence1. Other factors that increase the risk of recurrence are extensive tumour cell necrosis and incomplete excision of the tumour at myomectomy. 1,6 The suggested treatment for recurrence is surgical excision, which can be followed by adjuvant therapy. This can be pelvic radiotherapy, chemotherapy with doxorubicin and cisplatin, hormonal therapy such as medroxyprogesterone and gonadotropin- releasing hormone analogue. 2,8,16 Conclusion The definition of STUMPs is evolving, with their classification still controversial. Their clinical behaviour is unpredictable, with the risk of malignant behaviour unknown. They are characterised by delayed recurrence which makes long term follow up very important. Patients need to be counselled about risk of malignancy and recurrence following diagnosis. Surgical management of choice is hysterectomy, although fertility-sparring myomectomy should be offered to those still desiring fertility. There is still many aspects to study with regards to these tumours, and standardisation of the diagnostic criteria may provide important data to understand them better. References 1. Maltese G, Fontanella C, Lepori S, et al. Atypical uterine smooth muscle tumors: A retrospective evaluation of clinical and pathologic features. Oncology. 2018;94(1):1-6. 2. Prewett s, Horan G, Hatcher H, et al. Borderline Sarcomas and Smooth Muscle Tumours of Uncertain Malignant Potential. Clin Onc. 2017;29:528-537 3. Kalogiannidis I, Stavrakis T, Dagklis T, et al. A clinicopathological study of atypical leiomyomas: Benign variant leiomyoma or smooth muscle tumor of uncertain malignant potential. Oncol lett. 2015;11(2006):1425- 1428. 4. Stewart EA, Quade BA, Laughlin-Tomasso S. Variants of uterine leiomyomas. In: UpToDate, Barbieri RL (Ed), UpToDate, Waltham, MA, 2017. 5. Haa HI, Choia MC, Heob JH, et al. A clinicopathologic review and obstetric outcome of uterine smooth muscle tumor of uncertain malignant potential (STUMP) in a single institution. Eur J Obstet Gynecol Reprod Biol. 2018;228:1-5. 6. Campbell JE, Knudtson JF, Valente PT, et al. Successful pregnancy following myomectomy for uterine smooth muscle tumor of uncertain malignant potential: A case report and review of the literature. Gynecol oncol rep. 2015;15(2016):1-3. 7. Mohlala BKF. Uterine leiomyomas: a review. Obstet Gynaecol Forum. 2005;15:5-11. 8. Joseph D, Chitrathara K. ‘‘The Uncertain and Unpredictable’’: Uterine Smooth Muscle Tumor of Uncertain Malignant Potential (STUMP)— Three Cases. Int J Gynaecol Obstet. 2018;16(40):1-5. 9. Bacanakgil BH, Deveci M, Karabük E, et al. Uterine smooth muscle tumor of uncertain malignant potential (STUMP): Clinicopathologic- sonographic characteristics, follow-up and recurrence. World J Oncol. 2017;8(3):76-80. 10. Babacan A, Kizilaslan C, Gun I, et al. CA 125 and other tumor markers in uterine leiomyomas and their association with lesion characteristics. Int J Clin Exp Med. 2014;7(4):1078-1083. 11. Macciò A, Chiappe G, Kotsonis P, et al. Abdominal leiomyosarcomatosis after surgery with external morcellation for occult smooth muscle tumors of uncertain malignant potential: A case report. Int J Surg Case Rep. 2017;38:107-110. 12. Gupta M, Laury AL, Nucci MR, et al. Predictors of adverse outcome in uterine smooth muscle tumours of uncertain malignant potential (STUMP): a clinicopathological analysis of 22 cases with a proposal for the inclusion of additional histological parameters. Histopathology. 2018;73:284-298. 13. Lim D, Alvarez T, Nucci MR, et al. Interobserver variability in the interpretation of tumor cell necrosis in uterine leiomyosarcoma. Am J Surg Pathol. 2013;37(5):650-658. 14. Kanayama S, Oi H, Kawaguchi R, et al. Immunohistochemical analysis of p16 expression in uterine smooth muscle tumors. Open J Obstet Gynecol. 2015;5:688-697. 15. Zhang Y, Jin M, Huang S, et al. Uterine smooth muscle tumor of uncertain malignant potential (STUMP) with coagulative necrosis: a comprehensive clinicopathologic study of 10 cases with long-term follow up. Int J Clin Exp Pathol. 2016;9(11):11065-11073. 16. Dall’Asta A, Gizzo S, Musarò A, et al. Uterine smooth muscle tumors of uncertain malignant potential (STUMP): pathology, follow-up and recurrence. Int J Clin Exp Pathol. 2014;7(11):8136-8142. 17. Mowers EL, Skinner B, McLean K, et al. Effects of morcellation of uterine smooth muscle tumor of uncertain malignant potential and endometrial stromal sarcoma: Case series and recommendations for clinical practice. J Minim Invasive Gynecol. 2015;22(4):601-606. 18. Başaran D, Özg l N, Selçuk I, et al. Uterine smooth muscle tumors of Unknown Malignant Potential (STUMP): A dilemma for gynecologists and pathologists. Gynecol Obstet Reprod Med. 2013;19:55-57. OBSTETRICS & GYNAECOLOGY FORUM 2019 | ISSUE 2 | 29 Obstetrics & Gynaecology Forum Visit our website: www.ihpublishing.co.za O&G FORUM