Hashimoto’s disease is the most common cause of hypothyroidism in the United States. This autoimmune disorder, also known as chronic lymphocytic thyroiditis, occurs when the body’s immune system mistakenly attacks the thyroid gland. This chronic attack causes inflammation and damage, impairing the gland’s ability to produce sufficient thyroid hormones. To understand the origins of this widespread condition, one must look back to the Japanese surgeon who first identified its unique characteristics.
Hakaru Hashimoto: The Man Behind the Name
Hakaru Hashimoto was born in 1881 in the village of Iga, Japan, into a family with a long-standing tradition of practicing medicine. He pursued his medical education at the Third High School in Kyoto before enrolling in the Fukuoka Medical College, which later became part of Kyushu University. Hashimoto was among the first class to graduate from the college in 1907, after which he began his surgical training under the mentorship of Professor Hayari Miyake.
During his four years in the First Surgical Bureau, he developed the observational skills that would lead to his famous discovery. Following his surgical training, Hashimoto traveled to Europe in 1912 to further his studies, a common practice for ambitious Japanese physicians at the time. He specifically went to the University of Göttingen in Germany to study pathology under the esteemed Professor Eduard Kaufmann.
His time in Germany was cut short by the outbreak of the First World War, forcing him to return to Japan in 1915. Upon his return, he briefly worked at his alma mater before settling in his hometown to take over his family’s private practice as a surgeon and general practitioner. Hashimoto treated patients until his untimely death from typhoid fever in 1934 at the age of 52.
The Seminal 1912 Discovery
The scientific contribution that secured Hashimoto’s place in medical history occurred during his surgical residency, while he was preparing his medical thesis. He examined the thyroid tissue specimens of four middle-aged female patients who had undergone surgery for goiters, or enlarged thyroid glands. He noticed a distinct pathological pattern that had never been documented in medical literature before this time.
Hashimoto published his findings in 1912 in the German surgical journal Archiv für Klinische Chirurgie, titling his paper Zur Kenntnis der lymphomatösen Veränderung der Schilddrüse (Struma lymphomatosa). The Latin term struma lymphomatosa was the name he gave to the disease, emphasizing the heavy presence of white blood cells within the gland. Hashimoto noted four specific histological features that marked this new condition:
- Extensive infiltration of the thyroid tissue by lymphocytes, often organized into distinct lymphoid follicles complete with germinal centers.
- Significant changes in the thyroid epithelial cells, which had transformed into large, eosinophilic cells.
- Destruction and atrophy of the normal thyroid follicles.
- An increase in the connective tissue, which caused fibrosis within the gland.
Global Recognition and Naming
Despite the publication of his detailed paper, Hashimoto’s discovery received little attention from the global medical community for several decades. The paper’s publication in German and its origin from a relatively isolated medical center in Japan meant the work was largely overlooked. Many European pathologists mistakenly categorized struma lymphomatosa as an early or variant form of the already known Riedel’s thyroiditis.
The findings were “re-discovered” in the 1930s, primarily in the United States, as more cases matching Hashimoto’s description began to appear. The true significance of the condition was not fully understood until the mid-1950s. In 1956, two independent groups of researchers demonstrated the presence of specific antibodies against thyroid components in the blood of patients with the disease. This finding confirmed that Hashimoto’s condition was an autoimmune disorder, marking it as the first organ-specific autoimmune disease ever identified. Following this validation, the medical community posthumously renamed struma lymphomatosa to “Hashimoto’s disease” or “Hashimoto’s thyroiditis.”