I believe they mean that the random variables have a common support. For example, if X ~ Unif[0,2] and Y ~ Unif[1,3], then their respective PDF's overlap in the interval [1,2], meaning the only interval where both X and Y can have common values is [1,2]. To illustrate, below is a representation of the supports of X and Y, below which is a representation of the real line.
1 Thyroid cancer is a malignant tumor of the thyroid gland. 2  Symptoms of thyroid cancer include swelling in the neck (goiter), neck pain, hoarseness, swallowing and breathing problem, swollen lymph gland in the neck.
Sometimes, a cancerous thyroid nodule can't be seen or felt by you or your doctor. In those cases, you may notice a swollen lymph node instead. Lymph nodes fight infection and are located throughout your body. If thyroid cancer spreads to the lymph nodes in your neck, then the lymph nodes will become swollen. Lymph nodes can become enlarged for a variety of reasonsâmany of them not related to thyroid cancer. When you have a severe sore throat, for instance, the lymph nodes in your neck may swell.