Primary isolated hepatic tuberculosis mimicking small hepatocellular carcinoma: A case report

Abstract

Rationale: Mycobacterium tuberculosis (TB) remains a serious threat in developing countries. Primary isolated hepatic tuberculosis is extremely rare. Because of its non-specific imaging features, noninvasive preoperative imaging diagnosis of isolated hepatic tuberculoma remains challenging.

Patient concerns: A 48-year-old man was admitted to our hospital due for suspected liver neoplasm during health examination.

Diagnoses: The tests for blood, liver function, and tumor markers were within normal range. Preoperative ultrasonography (US) showed a hypoechoic lesion with a longitudinal diameter of 2.5 cm in segment six of liver. It exhibited early arterial phase hyperenhancement and late arterial phase rapid washout in contrast-enhanced US. It demonstrated hyperintensity in T2-weighted magnetic resonance imaging and partly restricted diffusion in diffusion-weighted imaging. For this nodule, the preoperative diagnosis was small hepatocellular carcinoma (HCC).

Interventions: Laparoscopic hepatectomy was performed. Intraoperative extensive adhesion in the abdominal cavity and liver was found. The lesion had undergone expansive growth.

Outcomes: Microscopically, a granuloma with some necrosis was detected. With both acid-fast staining and TB fragment polymerase chain reaction showing positive results, TB was the final histology diagnosis. After surgery, the patient declined any anti-TB medication. During the follow-up, he had no symptoms. In the sixth month after surgery, he underwent an upper abdominal US. It showed no lesions in the liver.

Lessons: Because of non-specific imaging findings and non-specific symptoms, a diagnosis of isolated hepatic TB is difficult to make, especially for small lesions. A diagnosis of HCC should be made cautiously when small isolated lesions in the liver are encountered, especially in patients without a history of hepatitis and with negative tumor markers.

Figure 1

A: A hypo echoic lesion with a size of 2.5 cm x 1.8 cm located in the sixth segment of liver was detected on the transabdominal US. B: The lesion showed hyper enhancement on early arterial phase (white arrow) and quickly wash-out on late arterial phase (red arrow) after intravenous injection of sulfur hexafluoride-filled micro bubble contrast agent. C: A hyper intensity lesion with a size of 2.1 cm x 1.7 cm on T2-weight image of MRI was presented. D: The hyper intensity lesion was partly diffusion restricted on diffusion-weighted MR images.

Figure 2

The lesion was fish like and irregular in the general pathology after surgical excision.

Figure 3

A: Histological examination detected granuloma with some necrosis (HE × 200). B: TB fragment polymerase chain reaction showed positive results.