**Core Concept**
The adrenal glands are a common site for metastasis from various primary tumors due to their rich blood supply and anatomical location near major vessels. This phenomenon is a result of the body's tendency to spread cancer cells through the bloodstream.

**Why the Correct Answer is Right**
Metastasis to the adrenal glands is a relatively common occurrence, especially in patients with a history of solid organ cancers such as lung, breast, colon, or melanoma. This is because cancer cells from these primary sites can easily disseminate through the bloodstream and lodge in the adrenal glands due to their high vascularity. The adrenal glands' proximity to major vessels, including the inferior vena cava and aorta, also contributes to their susceptibility to metastasis.

**Why Each Wrong Option is Incorrect**
**Option A:** Adrenocortical carcinoma is a primary adrenal tumor, but it is much rarer than metastasis to the adrenal glands. While it can be malignant, it is not the most common cause of a malignant adrenal mass.
**Option B:** Malignant phaeochromocytoma is a primary adrenal tumor that can be malignant, but it is relatively rare compared to metastasis to the adrenal glands.
**Option C:** Lymphoma can involve the adrenal glands, but it is not the most common cause of a malignant adrenal mass. Lymphoma typically involves the lymph nodes and other lymphoid tissues first.

**Clinical Pearl / High-Yield Fact**
When evaluating a patient with a malignant adrenal mass, it is essential to consider the possibility of metastasis from another solid organ tumor, particularly if the patient has a history of cancer. A thorough review of the patient's medical history and imaging studies is crucial in determining the primary site of the malignancy.

**✓ Correct Answer: D. Metastasis from another solid tissue tumor**