L72.3

Sebaceous cyst

A sebaceous cyst (L72.3) is a benign, slow-growing encapsulated lesion located within the dermis or subcutaneous layers of the skin. In clinical nomenclature, the term 'sebaceous cyst' is frequently applied to any cutaneous cyst, but it strictly refers to a cyst originating from the sebaceous glands, usually caused by the obstruction of a sebaceous duct. These cysts are typically filled with sebum, a fatty, yellowish substance, and are often associated with the pilosebaceous unit. While commonly found on the face, neck, trunk, and scalp, they can occur anywhere on the body where hair follicles and sebaceous glands are present. They are generally asymptomatic unless they rupture—leading to a sterile inflammatory response—or become secondarily infected by cutaneous flora, resulting in abscess formation. Though not cancerous, they require clinical management if they cause significant discomfort, become infected, or for cosmetic reasons.

Clinical Symptoms

  • Small, round, firm lump under the skin
  • Central punctum (a tiny blackhead-like opening in the center of the cyst)
  • Thick, yellow, foul-smelling cheesy discharge (if expressed or ruptured)
  • Redness and localized warmth if inflamed
  • Tenderness or pain upon palpation if infected
  • Restricted movement if the cyst is located near a joint
  • Fluctuant mass that moves slightly under the skin
  • Localized edema following a rupture

Common Causes

  • Blockage or obstruction of the sebaceous gland duct
  • Trauma or injury to the skin (e.g., scratches, surgical wounds)
  • Excessive production of sebum due to hormonal fluctuations
  • Deformed or damaged hair follicles
  • History of acne vulgaris
  • Genetic syndromes such as Steatocystoma multiplex
  • Gardner syndrome (associated with multiple cutaneous cysts and polyposis)
  • Exposure to certain chemicals or environmental pollutants

Documentation & Coding Tips

Distinguish between sebaceous, epidermal, and pilar cysts to ensure the most specific ICD-10-CM code assignment.

Example: Clinical evaluation of a 2.0 cm nodule on the mid-back reveals a sebaceous cyst rather than an epidermal inclusion cyst. The patient has a history of cystic acne which contributes to the development of these sebaceous lesions. Billed as L72.3 with CPT 11402 for excision of a benign lesion on the trunk.

Billing Focus: Anatomical site and pathological origin.

Document the size of the lesion including the narrowest margins if an excision is performed to support CPT code selection.

Example: Sebaceous cyst on the scalp measures 1.5 cm in diameter. After including 0.25 cm margins on each side, the total excised diameter is 2.0 cm. Procedure documented for CPT 11422. Patient's chronic tobacco use is noted as a factor impacting wound healing risk.

Billing Focus: Lesion size and margin measurements.

Clearly document signs of inflammation or infection, as this may shift the primary diagnosis to an abscess if drainage is required.

Example: Sebaceous cyst on the right shoulder is erythematous, warm, and fluctuant, indicating secondary infection. Incision and drainage performed (CPT 10060). Primary code L72.3 with secondary code L02.411 for cutaneous abscess of right upper limb.

Billing Focus: Presence of infection and laterality.

Note the presence of a central punctum or discharge of sebum, which are key clinical indicators of a sebaceous cyst.

Example: Exam of the neck shows a 1.0 cm sebaceous cyst with a visible central punctum and expression of thick, foul-smelling sebum. No signs of cellulitis. Patient is immunocompromised due to active chemotherapy, increasing risk for post-procedural infection.

Billing Focus: Clinical morphology supporting diagnosis.

Specify the exact anatomical location and laterality for all lesions to comply with ICD-10-CM specificity requirements.

Example: Multiple sebaceous cysts noted on the left scrotum. No evidence of malignancy or torsion. Patient scheduled for elective excision. Condition is chronic and recurrent, impacting the patient's quality of life.

Billing Focus: Laterality and specific anatomical sub-site.

Relevant CPT Codes