**Core Concept**
Malignant ameloblastoma is a rare, aggressive variant of ameloblastoma, a type of odontogenic tumor that arises from the epithelial cells of the tooth germ. The malignant transformation is characterized by the presence of cellular atypia, increased mitotic activity, and invasion of surrounding bone.

**Why the Correct Answer is Right**
Malignant ameloblastomas exhibit histological features of malignancy, including pleomorphic cells, increased nuclear-to-cytoplasmic ratio, and the presence of mitotic figures. The tumor cells may also produce mucin, leading to a characteristic "mucoid" or "myxoid" appearance. The malignant transformation is thought to be related to mutations in the TP53 gene, which is a tumor suppressor gene that regulates cell growth and division.

**Why Each Wrong Option is Incorrect**
**Option A:** Malignant ameloblastomas are typically found in the posterior mandible, but they can also occur in the maxilla or other bones of the skull. This statement is incorrect because it implies a specific location that is not universally true.

**Option B:** While some ameloblastomas may exhibit bony expansion, this is not a characteristic feature of malignant ameloblastomas. Malignant ameloblastomas tend to be more aggressive and destructive, with a higher likelihood of cortical perforation and invasion of surrounding soft tissues.

**Option C:** This statement is incorrect because it implies that malignant ameloblastomas are always associated with a specific clinical presentation, such as a painful swelling or a draining sinus tract. In reality, the clinical presentation of malignant ameloblastomas can be variable and may not always be distinctive.

**Option D:** This statement is incorrect because it implies that malignant ameloblastomas are always curable with surgery. While surgical excision is often the primary treatment for malignant ameloblastomas, the prognosis is often guarded due to the potential for recurrence and metastasis.

**Clinical Pearl / High-Yield Fact**
Malignant ameloblastomas are rare, but they should be suspected in any case of an aggressive odontogenic tumor with features of cellular atypia and invasion. A high index of suspicion and a thorough histopathological evaluation are essential for making an accurate diagnosis.

**Correct Answer: B.**

✓ Correct Answer: D. Metastasizing tumor that is cytopathologically similar to its benign counterparts in both primary and metastatic deposits.