Simple Liver Cyst as A Differential Diagnosis of Right Adrenal Cyst

SH is a rare entity, with an estimated prevalence of 10-20%. It is more common in women, especially those over 40 years of age. In general, they are usually incidental findings during surgical interventions, autopsies or imaging studies. The most common presentation is small-sized SH (<5 cm), characterized by thin walls and an asymptomatic course. However, when the size of the SHQ exceeds 5 cm, they can generate gastrointestinal symptoms such as abdominal pain or distension, palpable mass, postprandial fullness and secondary to infection, rupture or bleeding (1).

In the study of SHQ, laboratory tests are usually normal, and the diagnosis is based on clinical and imaging studies. Among the radiological tests, ultrasound, CT and MRI stand out (2). Although these lesions do not present radiological pathognomonic characteristics. Radiological criteria include: rounded mass, smooth edges, thin and regular walls, without internal structures (1).

The differential diagnosis of SHQ can be complex, especially when faced with premalignant liver lesions such as mucinous cystic neoplasia (MCN) and biliary intraductal papillary neoplasia (IBPN). It is also essential to rule out the presence of focal nodular hyperplasia, cystadenoma and cystadenocarcinoma.

In particular, hydatid cysts should be considered, the exclusion of which requires serological studies (2,3).

Likewise, among the possible entities to be taken into account is the adrenal incidentaloma, specifically the right adrenal cyst. Regarding adrenal incidentalomas, they are lesions of the adrenal gland larger than 1 cm, diagnosed incidentally (4). Cystic adrenal masses, mainly simple adrenal cysts (SACs), share important similarities with SHCs. SHCs are rare or infrequent lesions, with an incidence of 1-2% (5). They usually appear in young women, between the third and sixth decades of life, and generally, unilaterally. Clinically, these lesions are asymptomatic in most cases. However, when they are associated with symptoms, these include abdominal pain, gastrointestinal discomfort or palpable masses, similar to SHCs. The diagnostic approach should include the evaluation of hormonal function and the risk of malignancy (4,6).

At the radiological level, both in CT and MRI, SSQs are characterized by being rounded, well-defined and thin-walled images. They show hyperintensity in T2 sequences, without contrast enhancement. Histologically, they are classified into four types: endothelial cysts (45%), pseudocysts (39%), epithelial cysts (9%) and parasitic cysts (7%) (5,7–9).

Treatment of SSQs is indicated in the presence of symptoms or suspicion of malignancy. Drainage or aspiration of the cyst is not recommended due to the high recurrence rate, with minimally invasive surgery being the treatment of choice. In the absence of suspicion of malignancy, and with surgical indication due to symptoms, laparoscopic fenestration is preferred. On the contrary, when malignancy is suspected, complete excision of the cyst is recommended (10).

In the case of SSQ, management remains a controversial issue. The most accepted criteria for surgical intervention include the presence of symptoms, tumor size (>5 cm) and suspicion of functionality or malignancy. Although there is no consensus on the ideal surgical technique, which may include enucleation, decortication, marsupialization or adrenalectomy (7). Laparoscopy is considered the approach of choice whenever feasible. Therefore, hepatic and adrenal cysts are rare entities that share similar clinical and radiological characteristics, which raises the

need to perform an accurate differential diagnosis. Both conditions have a low prevalence and are more common in women, generally 6 around the fifth decade of life. They usually occur asymptomatically, although in some cases they may be associated with gastrointestinal symptoms. The diagnosis of these lesions requires the use of various imaging tests, such as ultrasound, CT or MRI. However, the anatomical proximity between the liver and the right adrenal gland can make it difficult to distinguish between the two pathologies, increasing the risk of erroneous diagnoses.

A thorough anamnesis, complemented by appropriate analytical studies and imaging tests, is essential to guide the diagnosis. However, in the majority of cases, the definitive diagnosis can only be established after the removal of the lesion and its subsequent anatomopathological study. Surgical treatment is mainly indicated for large cysts that present symptoms or when there is suspicion of malignancy.