Exulceration of the neck skin is common finding in patients with anaplastic thyroid cancer, it may also occur in certain aggressive neglected poorly differentiated variants of papillary carcinoma like tall cell and hobnail variant.

We present a 73-years old woman with large exulcerated tall-cell thyroid tumor. Patient had multinodular goiter for 20 years, not wanting to operate. In the last three months patient noticed rapid growth of goiter, followed by exulceration.

Papillary carcinoma was diagnosed on aspiration biopsy. Total thyroidectomy with en-block resection of the infrahyoid muscles and skin was performed. Pathologically, goiter and tall-cell carcinoma were present. Postoperative radioiodine therapy was done, than suppressive therapy, patient refused radiotherapy. Thyroglobulin was 0.15 ng/ml. For the next three years patient didn't come at routinely check up and after 3 years she came with tracheostomy and local recurrence of disease. Thyroglobulin was 9 ng/ml. Aspiration biopsy finding was papillary cancer, again. Second surgery was performed - tumor reduction, the defect was reconstructed with fasciocutaneous transpositional flap. Pathologically finding confirmed tall-cell carcinoma with regional lymph node metastases. Patient refused radioiodine and transcutaneous radiotherapy and died 4 years after first operation. We also report neglected hobnail cancer, one in 5 cases operated on since 2018.

The reliability of aspiration biopsy of tall cell and hobnail papillary cancer is questionable. The expression of thyroglobulin is very weak which diminishes its significant role in the evaluation of the radicality and postoperative monitoring. Neglected tall cell and hobnail cancer can be unpredictable even in radically performed operation.