COMPUTED TOMOGRAPHIC APPEARANCE OF MELANOMAS IN THE EQUINE HEAD: 13 CASES.

The research study focuses on the use of Computed Tomography (CT) to observe the characteristics of melanomas, a common type of tumor, in horses’ heads. The study investigates the physical properties of these tumors using CT images obtained from thirteen horses and explores the locations where the tumors are most often found.

Methodology

• For the study, the researchers examined the previous case records from two referral hospitals.
• They selected 13 horses that had undergone CT scans of the head and had been diagnosed with melanoma based on cytology, histopathology, or direct visual identification of black tissue (indicative of melanotic melanoma).
• During the course of the study, they recorded the number of melanomas in each horse, noting a median of 11 tumors per horse (with a range of 3 to 60). The total number of tumors found among the 13 horses was 216.

Findings

• The researchers found that the melanomas were commonly located in the parotid salivary gland, guttural pouches, around the larynx and pharynx, and next to the hyoid apparatus.
• When examining the non-contrast CT images, they found that the melanomas were hyperattenuating, meaning they appear brighter on the images compared to the surrounding masseter musculature.
• They also found that a large portion (25.9%) of the tumors were partially mineralized, and a significant number (19.4%) included hypoattenuating areas, indicating uneven density within those tumors.
• Upon histopathological assessment, the researchers determined that the strong attenuation observed in the images was likely due to large amounts of melanin pigment within the tumor cells.

Conclusions

• The study concludes that melanomas in the head of horses exhibit consistent features on CT scans that can assist in identifying these tumors and determining their locations.
• However, the researchers also emphasized the importance of confirmatory histopathological analysis or direct visual identification for a definitive diagnosis of melanoma.