[1305] The Variable Pathologic Presentations of Medullary & Micro-Medullary Thyroid Carcinoma: An Institutional Experience

Teresa D Samulski, Virginia LiVolsi, Kathleen Montone, Zubair Baloch. Hospital of the University of Pennsylvania, Philadelphia, PA

Background: Medullary thyroid carcinoma (MTC) is a rare tumor which can present in both sporadic and familial forms. The pathologic diagnosis of MTC can be difficult due to variability in its clinical presentation, size and morphology. In this study, we report our institutional experience with 45 cases of medullary thyroid carcinoma diagnosed between 2000-2007.
Design: Forty-five cases of MTC diagnosed between 2000-2007 were retrieved from electronic pathology files at University of Pennsylvania Medical Center employing the search terms of “medullary”, “carcinoma” and “thyroid”. The data points recorded for this study included patient's age, sex, family history, size of tumor, method of diagnosis (fine needle aspiration (FNA) vs. biopsy vs. resection), pre- and post-operative calcitonin and CEA levels, presence of concomitant follicular derived thyroid carcinoma, lymph node status at time of resection, and clinical follow-up.
Results: The cohort included 17 males and 28 females (average age 53 yrs, median 51 yrs); of these, 6 had a history of multiple endocrine neoplasia II. Pre-operative FNA was performed in 33/45 cases (33%); 15 were diagnosed as consistent with MTC, 8 as suspicious for MTC and 10 as follicular neoplasm. Pre-operative calcitonin was available in 17 (range 4.1-1709 mg/L and CEA in 2 cases (range 3.4-20.9 mg/L) Based on size, 20 tumors were classified as micro-MTC (average size 0.35 cm) and 25 as macro-MTC (average size 2.8 cm); of these, 15 MTC (9 micro and 6 macro-MTC) occurred with other thyroid malignancies (papillary carcinoma 12, follicular carcinoma 2, and anaplastic carcinoma 1 case). Bilateral MTC were noted in 11 cases, including 4 cases of MENIIB. Lymph node metastases were present at primary resection in 18 (18/45 40%) cases; of these, 6 were from micro-MTC and 2 showed metastases only from concomitant papillary thyroid carcinoma. Clinical follow-up was available in 21 (21/45 47%) cases (range 1-146 months). In 4 patients the calcitonin levels rose or remained elevated postoperatively; of these, 2 had regional lymph node recurrence and 1 developed distant metastases to lung and liver and subsequently died of disease. No tumor recurrence or distant metastases were seen in cases of micro-MTC.
Conclusions: In our experience, MTC is a heterogeneous disease due to its clinical presentation, pathology, and follow-up. Its preoperative diagnosis can be accomplished by FNA. Sporadic micro-MTC carcinoma is an indolent tumor and can occur with other malignant tumors of the thyroid gland.
Category: Head & Neck

Tuesday, March 5, 2013 9:30 AM

Poster Session III # 143, Tuesday Morning


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