An Unusual Mimicry

Abstract

A previously healthy 29-year old Hispanic woman, presented with progressive worsening abdominal pain and distension for 3 months. This was associated with fatigue, lower extremity edema, and unintentional weight loss. There was no family history of polycystic kidney or liver disease. Physical exam was positive for massive hepatomegaly. Initial laboratory work was significant for hypoalbuminemia (2.0 g/dL) and elevated alkaline phosphatase (278 IU/L). MRI of the abdomen revealed massive hepatomegaly with multiple cystic lesions (Fig 1a & b). Additional investigations that included testing for Echinococcus granulosus and Entamoeba histolytica serology, Alpha-Fetoprotein, and PRKCSH and SEC63 gene testing for polycystic liver disease were negative. Interestingly, she had a normal imaging of the abdomen 6-years prior to this presentation (Fig 1c). IR guided biopsy of the liver cyst was consistent with simple cyst and negative for infection or malignancy. She was diagnosed with polycystic liver disease. Hospital course was complicated by progressively worsening liver failure, alongside renal and respiratory failure secondary to massive hepatomegaly causing compression on vital organs. After a long discussion, a joint decision was made by multidisiplinary teams to send patient for liver transplantation due to her rapid decompensation. Unfortunately, she succumbed to cardiac arrest during the procedure. Autopsy showed 12.3 kilos massive liver (Fig 2). Histology and immuno-chemistry confirmed the diagnosis of primary peripheral neuro-endocrine tumor of liver with metastases to vertebral bone marrow, bilateral lungs, and brain duramater (Fig 3). Neuro-endocrine tumors develop in tissues that contain peptide- and amine-producing cells (gastroenteropancreatic system-57% and bronchopulmonary system-27%). There are fewer than 150 cases of primary liver neuro-endocrine tumor reported in current literature. Rarely, they present as multiple cystic lesions of the liver. Our case is unique in that our patient presented with massive hepatomegaly with innumerable cystic lesions, mimicking autosomal dominant polycystic liver disease, which unfortunately, led to confusion and delay in diagnosis. Primary neuro-endocrine tumor of the liver is a very rare entity. This case highlights the importance of considering other differential diagnosis during the evaluation of cystic lesions of the liver especially when family history, kidney involvement, and gene testing are negative.Figure 1Figure 2Figure 3