Caput succedaneum: A common condition in newborns, characterized by a soft, puffy swelling of the scalp, often caused by pressure exerted during a head-first delivery. It typically appears on the occipital region and resolves spontaneously.

Cephalohematoma: A collection of blood between the skull and its covering, often resulting from birth trauma. It presents as a well-defined, firm mass on the scalp, usually on one side of the head, and may take weeks to resolve.
Subgaleal hemorrhage: Bleeding into the space between the skull and the scalp, which can be life-threatening if large. It may present as a soft, fluctuant mass that can cross suture lines.
Congenital dermal sinus: A rare congenital anomaly that can present as a midline scalp mass, often in the occipital region. It may be associated with spinal dysraphism.

Meningocele or Myelomeningocele: Congenital defects of the spine and spinal cord that can present as a mass in the occipital region, especially if the defect is high in the spine. These conditions require urgent surgical intervention.
Teratoma: A type of tumor that can occur in the scalp, including the occipital region. While rare, teratomas can be large and may have significant implications for the infant's health.

Encephalocele: A rare congenital anomaly where the brain and meninges herniate through a defect in the skull, which can present as an occipital mass.
Lipoma: A benign tumor composed of fat tissue, which can rarely occur in the scalp, including the occipital region.
Neurofibroma: A benign tumor of the nerve tissue, which can present as a scalp mass, including in the occipital region, especially in the context of neurofibromatosis type 1.