Bilateral Primary Ovarian Amelanotic Malignant Melanoma Arising in a Mature Teratoma in Pediatric Age Group


Hiral. A. Shah, Kalpana Chandra, Ankit. A. Shah, Pranab. K. Verma    11 July 2018


Amelanotic melanoma, ovarian teratoma.


Metastatic malignant melanomas are more common than primary malignant melanomas of the ovaries. If primary malignant melanomas occur they always manifest in a background of teratomas, as ovaries normally do not contain melanin producing cells [1]. Amelanotic melanomas are a rare subtype of melanoma which is devoid of pigments and constitutes about 2% to 8% of all malignant melanoma cases [2].Here we are reporting an extremely rare case of bilateral ovarian mature teratoma transformed in to primary amelanotic malignant melanoma with multiple metastatic lesions in a 13 year old female child.

About the Authors

Senior Resident, Dept. of Pathology, Mahavir Cancer Sansthan, Patna

Assistant Professor, Dept. of Pathology, IGIMS, Patna

Third year DNB trainee, Dept. of Surgery Oncology, Mahavir Cancer Sansthan, Patna.

Consultant Pathologist, Dept. of Pathology, Mahavir Cancer Sansthan, Patna


A 13 year old female patient presented to our hospital with the complaints of lump and pain abdomen for three months. She had attained menarche six months back with regular cycles. Past and family history were unremarkable. On abdominal examination, she was having a hard mobile lump in the periumbilical and hypogastric region with evidence of free fluid. CT scan showed a large heterogeneously enhancing solid cystic mass in the lower abdomen and pelvis with foci of calcification and fat density lobule. Multiple enhancing deposits were seen in the pelvis with multiple retroperitoneal nodes and moderate ascites. Features were suggestive of malignant ovarian teratoma with peritoneal deposits. Laboratory investigations included tumor marker tests (AFP, HCG, CEA) which were within normal limits with exceptionally raised CA 125 >1000U/ml. So cytoreduction surgery was done which included bilateral salpingo-oophorectomy, bilateral pelvic lymphnode dissection, para aortic lymph node dissection with supracolic omentectomy and preservation of uterus and cervix.

On gross examination right and left ovaries were well encapsulated and measured 6.5*4*3 cm3 and 23*13*9 cm3 respectively. On cut, both ovaries were partly cystic containing sebum like pultaceous material and bunch of hair follicles. Solid area was firm on cut, tan white. Both fallopian tubes were unremarkable. Microscopically, sections from solid area showed sheets and lobules of epitheloid cells. Many of the tumor cells show multinucleation, bizarre nuclear pleomorphism and brisk atypical mitosis. The nucleoli were prominent. The cytoplasm was abundant, eosinophilic and foamy at places. No brown pigment was observed in the cytoplasm of tumor cells. Apart from this moderate amount of lymphocytic infiltrates were present on the lobular septa. Cystic area was partially covered by squamous epithelium with many hair follicles, sebaceous glands and adipose tissue present in the underlying stroma. No other structures were identified which could lead to the diagnosis of epithelial malignancy as suspected by raised CA125 level. The microscopic cytomorphology, bilaterality and pediatric age group led to the histological diagnosis of anaplastic dysgerminoma with syncytiotrophoblastic giant cells and component of mature dermoid cyst. As there was discrepancy in the histopathology report and clinical diagnosis, IHC was performed at our centre as well as slide was sent for second opinion.

Based on IHC studies a final diagnosis of bilateral primary amelanotic malignant melanoma with component of mature cystic teratoma was rendered.


Mature cystic teratomas are the most common benign germ cell tumors of the ovary, and constitute 15-25% of ovarian tumors overall [3]. Malignant changes in dermoid cysts of the ovaries are rare; occurring in 0.2-2% of the cases and squamous cell carcinoma are the commonest, accounting for 88% of all malignancies [4]. In the present case it was very challenging to label it as a primary tumor as bilaterality strongly favored metastatic tumor as per the criterion laid by Brought et al. and Croje &Woodruff [5, 6]. Secondly, our patient was in pediatric age group whereas youngest female presented with primary malignant melanoma of ovary reported in literature by Carlson JA Jr, Wheeler JE. et al. was 20 years old female.[7] Our patient was re-evaluated further and the possibility of melanoma at any other site, mainly skin, central nervous system, eye, vagina , vulva and gastrointestinal tract was ruled out. There was no clinical evidence or previous history of malignant melanoma. As no primary site was identified only one possibility was left behind as either regression of a cutaneous melanoma or non cutaneous melanoma which was not picked up on CT scan.

However, the teratomatous component was so well developed in both the ovaries with microscopic breach in the capsule of left ovary, the pathogenesis which we could understand is that initially both the ovaries developed dermoid cyst. Probably the left ovary developed the dermoid cyst first as evidenced by its size and then gradually due to some unexplained reason the malignant change occurred followed by capsular breach and its metastasis to the contralateral ovary as well as sigmoid colon, pouch of douglas and peritoneum. Amelanotic form of melanoma is very difficult to diagnose on conventional histopathology techniques as cytomorphology resembles many primary tumors of ovary. IHC plays a vital diagnostic tool for this ovarian neoplasm.

In anaplastic dysgerminoma with syncytiotrophoblastic giant cells, polygonal tumor cells are arranged in lobules or sheets having distinct cell membrane, abundant cytoplasm, round to oval central nuclei with prominent nucleoli. Numerous mitotic figures with syncytiotrophoblastic giant cells are present in the background. CA 125 was raised significantly which raised the possibility of epithelial malignancy. In both the above differentials IHC markers were against the diagnosis.


Primary malignant melanoma of ovary in pediatric age especially amelanotic subtype is extremely rare and presents a diagnosis challenge simulating primary ovarian malignancy. IHC is a valuable diagnostic tool in establishing the definite diagnosis for this type of rare tumors.


  1. Hermann W Humes J. A Compound Nevus in a Benign Cystic Teratoma of the Ovary. American Journal of Clinical Pathology. 1976; 66(1):54-58.
  2. Huvos AG, Shah JP, Goldsmith HS. A clinicopathologic study of amelanotic melanoma. Surg Gynecol Obstet. 1972 Dec; 135(6):917–920.
  3. Lee S, Kim J, Chon G, Kim A, Kim B. Primary Malignant Melanoma Arising in an Ovarian Mature Cystic Teratoma - A Case Report and Literature Review -. Korean J Pathol. 2011; 45(6):659.
  4. Borup K, Rasmussen K, Schierup L, Møller J. Amelanotic malignant melanoma arising in an ovarian dermoid cyst. Acta Obstetricia et Gynecologica Scandinavica. 1992; 71(3):242-244.
  5. Boughton R, Hughmanick S, Marin-Padilla M. Malignant melanoma arising in an ovarian cystic teratoma in pregnancy. Journal of the American Academy of Dermatology. 1987; 17(5):871-875.
  6. Cronje H Woodruff J. Primary ovarian malignant melanoma arising in cystic teratoma. Gynecologic Oncology. 1981;12(3):379-383.
  7. Carlson J Wheeler J. Primary Ovarian Melanoma Arising in a Dermoid Stage IIIc: Long-Term Disease-Free Survival with Aggressive Surgery and Platinum Therapy. Gynecologic Oncology. 1993; 48(3):397-401.

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