Differential Diagnosis for a Baby with a Neck Mass
- Single most likely diagnosis
- First branchial cyst: This is a congenital anomaly that typically presents as a neck mass, often in the upper neck, and can become infected, leading to swelling and pain. The location and nature of the mass, along with the age of the patient, make this a strong consideration.
- Other Likely diagnoses
- Cat scratch disease (Bartonellosis): Given the mention of "cat" in the question, cat scratch disease is a plausible diagnosis. It can cause lymphadenopathy, which might be mistaken for a neck mass, especially if the lymph nodes are significantly enlarged.
- Tuberculosis (TB): TB can cause cervical lymphadenopathy, which might present as a neck mass. Although less common in infants, it's a consideration, especially in areas with high TB prevalence or in immunocompromised patients.
- Do Not Miss diagnoses
- Malignancy (e.g., neuroblastoma, lymphoma): Although rare, malignancies can present with a neck mass and are critical to diagnose early. Missing these diagnoses could have severe consequences, making them essential to rule out.
- Infectious causes (e.g., abscess, cellulitis): Serious infections can cause neck masses and require prompt treatment to avoid complications such as airway obstruction or sepsis.
- Rare diagnoses
- Thyroglossal duct cyst: A congenital anomaly that can present as a midline neck mass. It's less likely given the upper neck location often associated with first branchial cysts but remains a possibility.
- Branchial cleft cysts (second or third): While less common than first branchial cleft anomalies, these can also present as neck masses, typically lower in the neck than first branchial cysts.