Encapsulated noninvasive tumor of follicular cell origin with extensive necrosis treated by lobectomy alone without radioactive iodine therapy. The patient did not recur after a follow-up of 13 years. A, Low power of hypercellular tumor (T) with its capsule (cap) free of invasion. B, Medium power showing extensive necrosis (N) surrounded by a tumor with a solid/nesting growth pattern. C, Tumor necrosis (N) was defined by a “comedo-like” appearance composed of degenerating cytoplasm and punctuate, karyorrhectic nuclear debris. D, High-power view showing round normochromatic tumor nuclei (resembling follicular adenoma/carcinoma nuclei) adjacent to necrosis (N).