Occipital Scalp Nodule in a Newborn

A 4-week-old male infant was referred to dermatology for evaluation of a nodule on the occipital protuberance of 2 weeks' duration.The patient was born at 36 weeks and 6 days' gestation via an emergency cesarean delivery due to fetal distress.He later was found to have hypoxic-ischemic encephalopathy, pulmonary hypertension, and hypertrophic cardiomyopathy.He underwent therapeutic hypothermia protocol treatment starting at less than 6 hours after birth.At the current presentation, physical examination showed a 2.5-cm, erythematous, firm, mobile nodule on the occipital scalp with some overlying crusting and minimal surrounding erythema.No other cutaneous features or lesions were present.Initial laboratory findings were remarkable for hypercalcemia at 11 mg/dL (reference range, 8.5-10.5 mg/dL).Magnetic resonance imaging showed a faint abnormality in the subcutaneous tissue in this region without a noted connection to the underlying brain/meningeal matter.A punch biopsy was performed. WHAT'S THE DIAGNOSIS?a. cephalohematoma b. cold panniculitis c.