A rare case of an enlarged celiac lymph node diagnosed as an epidermal inclusion cyst

A 65-year-old man was admitted for treatment of necrotizing pneumonia in the right upper lung field and consulted to gastrointestinal department for evaluation of a hypoechoic mass in the celiac region. Vital signs were stable. Initial laboratory findings included hemoglobin 10.6 g/dL, aspartate aminotransferase 64 IU/L, alanine aminotransferase 83 IU/L, and C-reactive protein 4.58 mg/dL. Abdominal ultrasonography for elevated liver function tests showed a 3.5-cm hypoechoic mass in the porta hepatis (Fig. 1A) and multiple gallstones. Abdominal computed tomography revealed a 3.5-cm low-density, multi-lobulated mass at the celiac axis suggestive of tuberculous lymphadenopathy (Fig. 1B). Endoscopic ultrasound showed a 27-mm hypoechoic mass in the celiac region (Fig. 1C) and fine needle aspiration showed benign epithelial cells with lymphocytes and histiocytes. Polymerase chain reaction for tuberculosis and acid-fast staining of the aspirate were negative. Laparoscopic excisional biopsy of an enlarged celiac lymph node was performed. Histologic examination of the specimen showed a squamous epithelium-lined cyst containing keratin material, confirming the diagnosis of an epidermal inclusion cyst (EIC) within a lymph node (Fig. 2).

Figure 1.

Imaging. (A) Abdominal ultrasound examination shows a 3.5-cm hypoechoic mass in the porta hepatis. (B) Abdominal computed tomography revealed a 3.5-cm low-density mass at the celiac axis (white arrow). (C) Endoscopic ultrasound showed a 27-mm hypoechoic mass in the celiac region.

Figure 2.

Histologic examination of excisional biopsy specimen from a celiac lymph node showed a squamous epithelium-lined cyst containing keratin material, confirming the diagnosis of epidermal inclusion cyst (H&E, ×40).

EICs are rare and benign and characterized by nodules with layered walls of squamous epithelium. EICs usually occur in the scalp, face, neck, trunk, and extremities. The pathogenesis of EICs is uncertain. The relationship between previous surgery or trauma and EIC development has been reported. The most common sonographic finding of an EIC is a hypoechoic mass with variable echogenic foci. Although most cases are benign, rare cases of malignancies such as squamous cell carcinoma arising in EICs have been reported. There have been no previous reports of EIC arising in the celiac region. We report a rare case of enlarged celiac lymph node diagnosed as EIC.

This study was approved by Institutional Review Board (2018-11-025) and written informed consent was obtained from the patient.