Amyloidosis of the gastrointestinal tract and the liver: clinical context, diagnosis and management.

Amyloidosis is a group of disorders that can manifest in virtually any organ system in the body and is thought to be secondary to misfolding of extracellular proteins with subsequent deposition in tissues. The precursor protein that is produced in excess defines the specific amyloid type. This requires histopathological confirmation using Congo red dye with its characteristic demonstration of green birefringence under cross-polarized light. Gastrointestinal (GI) manifestations are common and the degree of organ involvement dictates the symptoms that a patient will experience. The small intestine usually has the most amyloid deposition within the GI tract. Patients generally have nonspecific findings such as abdominal pain, nausea, diarrhea, and dysphagia that can often delay the proper diagnosis. Liver involvement is seen in a majority of patients, although symptoms typically are not appreciated unless there is significant hepatic amyloid deposition. Pancreatic involvement is usually from local amyloid deposition that can lead to type 2 diabetes mellitus. In addition, patients may undergo either endoscopic or radiological evaluation; however, these findings are usually nonspecific. Management of GI amyloidosis primarily aims to treat the underlying amyloid type with supportive measures to alleviate specific GI symptoms. Liver transplant is found to have positive outcomes, especially in patients with specific variants of hereditary amyloidosis.

Hepatic sarcoidosis: pathogenesis, clinical context, and treatment options.

Sarcoidosis is typically characterized as a non-caseating granulomatous disease that has the ability to affect multiple different organ systems. Although extra-thoracic sarcoidosis can occur in the presence and also without lung involvement, isolated extra-pulmonary disease is rare. The liver is the third most commonly affected organ system after the lungs and lymph nodes. When discussing hepatic sarcoidosis it is important to keep in mind that many patients in this population may not present as one would typically expect since most of the patients are asymptomatic or have mild presentations. Therefore, the diagnosis can be difficult at times since no single laboratory or imaging study can definitively diagnose this systemic disease. In the rare case of some patients where there is difficulty in discerning between different pathologies, the use of image-guided tissue biopsy may be necessary to establish a diagnosis. At the current time, there are no clear guidelines for the management of hepatic sarcoidosis and are mostly dependent on a patient's clinical status at time of presentation. The current body of research in regard to treatment suggests steroids to be the mainstay of therapy. However, there is a role for additional immunosuppressive therapy in cases where the initial treatment is refractory to steroids. In this manuscript, we discussed the pathogenesis of liver sarcoidosis and context of its presentation. In addition, the differential diagnosis and imaging evaluation in this population is discussed. Finally, treatment options are reviewed in setting of previous studies for liver sarcoidosis.