Endocrine Abstracts

Distant metastasis in papillary thyroid microcarcinoma (PTMC) is rare but fatal; We report two cases of PTMC with skull and sellar region metastasis

Case 1: 16-year-old M.A presents with a swelling in the parietal region of the skull. She consults for cephalgias, sensation of intracranial hypertention and right parietal hump appeared six months rather. The spinal IRM concludes a solidokystic osteolytic process of the right parietal worm with endocranial development and a local pachy meningeal reaction\. The patient underwent total exeresis of the tumor with cranioplasty. Histological examination revealed the diagnosis of a bone metastasis of vesicular carcinoma of the thyroid. With positive staining for thyroid transcription factor -1 (TTF-1) and thyroglobulin (TG). The thyroid echography found two suspicious nodules TIRADS5. The patient was operated on and underwent a total thyroidectomy with recural lymph node dissection and bilateral jugulocarotidien. The histological study of the piece is in favor of a bilateral papillary microcarcinoma of 4 mm at left and of 3 mm on the right classified PT1m N0 M1. Totalized isotopically by 100mCi I131 and suppressive treatment with thyroxine.

Case 2: A 62-year-old woman presented with non-secretory pituitary macroadenoma. MRI of the brain revealed a tumor of4.x5,3.x1,3 cm, extension into the cavernous sinuse. Underwent a simple biopsy in view of the haemorrhagic nature of the tumor. Histopathology revealed a tumor with diffuse papillary architecture. On immunohistochemistry: positive for TTF1, PAX8, thyroglobulin, TPO;Ki67 (10–15%) and negative for GH, LH, FSH, ACTH, TSH. A diagnosis of metastatic papillary carcinoma was made. Thyroid ultrasound revealed two micro nodules. After thyroidectomy the histopathology was papillary micro- carcinoma thyroid-follicular variant of 05 mm. She received radioiodine therapy.

Discussion: Lymph node metastasis or extraglandular extension has been reported in the few published cases of metastatic PTMC, the majority occurring within 5 years of the initial diagnosis. There have been case reports of PTMC with metastasis at unusual sites like the breast and cavernous sinus. All these cases were associated with a missed diagnosis of thyroid carcinoma, like our cases

Conclusion: There is no consensus for the treatment of PTMC with cavernous sinus metastasis or skull metastasis The treatment of children and adolescents with differentiated thyroid carcinoma is more controversial than the treatment of adults. Primarily because of the rarity of skull metastasis with thyroid carcinoma, the role of standard postoperative therapy for this situation has not been definitively established.

Key word: MPTC, skull metastasis, pituitary metastasis