Congenital goiter with areas of signet ring cell differentiation in a juvenile giraffe: a very rare entity

A young giraffe stopped growing normally without a visible lump in her neck. Lulu began life at an apparently ordinary size, but developed a poor appetite, excessive salivation and slow growth. At eight months, she was only as tall as the report's typical four-month-old giraffe. The explanation emerged after her death.

Jinling Wang and colleagues examined the seventeen-month-old female from Ordos Zoo in China. They combined her clinical history and blood results with a postmortem examination, microscopic tissue sections and stains that identify thyroid proteins. The decisive task was to distinguish a developmental thyroid disorder from a tumour: some abnormal cells had swollen interiors that pushed their nuclei to the edge, an appearance sometimes associated with cancer.

Much of the thyroid had lost its normal structure, but the team found no convincing pattern of an invasive tumour. They diagnosed congenital goiter, a disorder involving abnormal thyroid development and growth. Thyroid hormones had not been measured during life, so the proposed hormone failure and iodine deficiency remained unconfirmed. The case shows why a giraffe's poor growth can warrant attention to the thyroid even when no neck swelling is obvious.