Sternocleidomastoid Enlargement

In humans, sternocleidomastoid muscles are responsible for neck flexion, rotation and extension.

The Association of American Family Physicians states that family doctors commonly find sternocleidomastoid enlargement (neck masses) in adults. While variations in neck anatomy do occur, these are usually diagnosed during childhood. Variations in neck muscles caused by disease can often be identified and diagnosed by a family practitioner.

In Adults

People of all ages can display sternocleidomastoid enlargement.

For doctors, the patient's age is an important factor for diagnosis. Sternocleidomastoid enlargement in young adults is often caused by inflammatory or infectious disease. In older adults, sternocleidomastoid enlargement can be a symptom of both benign and malignant tumors.

In Infants

In newborns, sternocleidomastoid enlargement is associated with torticollis, or "twisted neck." In newborns, a mass or enlargement of the sternocleidomastoid muscle may at first grow rapidly. However, these masses often stabilize and regress over time. In many cases, no sternocleidomastoid enlargement is detectable after age two. Enlargements may be due to birthing trauma or fetal position.

Lymph Nodes

Sternocleidomastoid muscles are attached to the jugular lymph nodes. These lymph nodes are located both above and below the SCMs, on both sides of the neck. Lymphatic draining in this area can cause sternocleidomastoid enlargement and a tender neck. Enlarged jugular lymph nodes are commonly caused by pharyngitis and rubella.

References

• ExRx.com: Sternocleidomastoid
• AAFP: The Adult Neck Mass
• Medcyclopedia: Fibromatosis colli
• Torticollis Kids
• DoctorsLounge: Neck Lymph Node Enlargement