Which type of carcinoma is characterized as more aggressive than papillary carcinoma and spreads through the bloodstream?

The type of carcinoma that is characterized as more aggressive than papillary carcinoma and has a propensity to spread through the bloodstream is anaplastic carcinoma. Anaplastic carcinoma is known for its aggressive clinical behavior, including rapid growth and widespread metastasis, which often occurs via the bloodstream rather than lymphatic channels. This high level of aggressiveness and tendency for hematogenous spread distinguishes it from other forms, such as papillary and follicular carcinoma, which typically have a more indolent course and less aggressive metastatic potential.

While medullary carcinoma is also aggressive, it primarily tends to spread locally rather than through hematogenous routes. Understanding the distinct biological behavior and metastatic patterns of these carcinomas is crucial for prognosis and therapeutic decision-making. Anaplastic carcinoma's characteristics represent a significant concern in oncology due to its aggressive nature and challenging management.