Mobile Subcutaneous Nodule in Antecubital Fossa

Case at a Glance

A 21-year-old African American female presented with a newly discovered mobile subcutaneous nodule in the left antecubital fossa, measuring approximately 1cm in diameter with overlying hyperpigmentation.

Patient's Story

The patient noticed a small, smooth, movable lump in the inner aspect of her left elbow after returning from work one day. She described the lesion as marble-sized, mobile, and associated with a darkened area of skin overlying it. The patient reported mild tenderness when pressure was applied, similar to the sensation experienced when manipulating a sebaceous cyst. She denied any trauma to the area, fever, or systemic symptoms.

Initial Assessment

Physical examination revealed a well-circumscribed, mobile subcutaneous nodule approximately 1cm in diameter located in the medial antecubital fossa. The overlying skin showed localized hyperpigmentation with a brownish discoloration. The lesion was non-tender at rest but became mildly uncomfortable with palpation and manipulation. No signs of inflammation, fluctuance, or lymphadenopathy were noted.

The Diagnostic Journey

Given the clinical presentation of a mobile, well-circumscribed subcutaneous nodule with overlying skin changes, differential diagnoses included sebaceous cyst, lipoma, dermatofibroma, or lymph node enlargement. The mobility and smooth texture suggested a benign etiology, most likely a sebaceous cyst or small lipoma.

Final Diagnosis

Sebaceous cyst (epidermoid cyst) with associated post-inflammatory hyperpigmentation

Treatment Plan

Conservative management with observation was recommended initially. Patient education was provided regarding signs of infection or inflammation that would warrant immediate medical attention. Options for surgical excision were discussed should the lesion become symptomatic, infected, or cosmetically bothersome.

Outcome and Follow-up

Patient was advised to follow up in 4-6 weeks or sooner if any changes occurred. Routine monitoring was recommended to ensure stability of the lesion and to address any patient concerns regarding cosmetic appearance or symptoms.