Malignant Thyroid Teratoma with Neuroectodermal Component: A Case Report

Keywords

Thyroid; Teratoma; Neuroectodermal; Tumor; Ecuador.

Introduction

Teratomas is defined by the presence of tissue from any of the three primordial germ layers and are mainly found in the gonads; and when it develops extragonadal it is often found in the midline [1].

The majority of malignant teratomas that involve the thyroid are relatively rare in adults, being more frequent its presentation in children and of these the great majorities are benign [2].

To our knowledge, this is the first case of malignant thyroid teratoma with a neuroectodermal tumor component reported in Ecuador.

Case Report

A 38-year-old male patient that presented a history of 2-month of a rapid growth of tumor mass dependent on the right side of the neck, measuring at a physical examination of 6.5 x 3.5 cm; no significant family or personal pathological background.

He underwent total thyroidectomy finding a tumor mass corresponding to the right lobe of 9.5 x 7 x 6cm, lymphovascular and perineural invasion absent, 4 nodes were isolated, all absent of tumor activity; the malignant germinal neoplasm is constituted by extensive neuroectodermal areas with glia, neural structures (more than 3 fields), which are demonstrated with stains for PGFA (glial fibrillary acidic protein); areas of mesenchyme, immature muscle and focal areas with differentiation to Saco of Yolk (alpha fetus protein positive), concluding as malignant thyroid teratoma with neuroectodermal component.

Immunohistochemistry: glial fibrillary acidic protein: positive, enolase, s100, AFP, myod1: positive ki-67: 50%.

Body tomography was requested 15 days after surgery, reporting negative for tumor activity, AFP: negative.

One month after having undergone surgery, chemotherapy treatment was started with a BEP scheme (bleomycin 30mg day 1 with reinforcement on days 8 and 15, cisplatin 20mg/m2 day 1 to 5, etoposide 100mg/m2 day 1 to 5) completing this scheme four cycles every 28 days.

After having concluded the chemotherapy sessions, the patient received intensity-modulated radiotherapy (IMRT) of 46 Gys and treated volume included the thyroid bed and cervical lymph nodes.

There was no need for dose reduction during chemotherapy and colony stimulating factors were used during the treatment, at the end of the radiotherapy presented grade 2 mucositis.

The patient remains in a disease-free period for 12 months.

Discussion

Malignant thyroid teratoma is an aggressive tumor with a median survival of 8 months with surgical treatment only and an approximate report of 30 cases worldwide [1, 2] being Jarayam who describes a case of survival 15 months after surgery only; It should be emphasized that, since the BEP scheme is the one most used for those who have documented this treatment, we have opted as the most favorable option for our patient [3, 4].

Chen J. describes his experience in 1998 reporting a case of malignant thyroid teratoma treated with a BEP scheme, presenting a disease-free survival of 6.5 years, without the use of radiotherapy [5-8].

Richard W. describes as an aggressive treatment using cisplatin in the BEP scheme, immediately after surgery, based on similar studies in Afro descendant women in the studies of Kimler, Muth and Ueno [2, 3, 9].

The role of Radiotherapy has often been discussed by entering into a line between whether or not there is a benefit according to several experiences, we have chosen to use IMRT radiotherapy because there was no correct lymph node emptying [10].

At the moment, the patient present an ECOG 0, remains in quarterly controls and was considered as a possible second line of treatment the P6 scheme described by Kushner in which cyclophosphamide, doxorubicin and vincristine were used, with patients with a complete response of up to 36 months [2, 11].

Conclusion

We consider that surgery should be a primary treatment accompanied by lymph node emptying as described in most of the literature of this disease and the use of Radiotherapy should be considered in the absence of surgical lymph node emptying, more studies of case reviews should be carried out in order to determine the best first line treatment scheme in this disease, however in this patient the BEP scheme has been well tolerated, presenting a clinical response.