Management of giant adrenal pseudocyst in pregnancy – A unique approach and review of literature

Abstract

Pseudocysts of the adrenal gland are rare and in the majority of cases are non- functioning. They become symptomatic only when they are complicated by hormonal excess, rupture, haemorrhage or infection. Described here is a 26-year-old woman who developed an acute abdomen at 28 weeks of gestation due to a left adrenal haemorrhagic pseudocyst. A conservative approach was adopted, which was followed by elective term caesarean delivery with surgical intervention at the same time. The described case is unique in terms of strategizing timing and mode of management and thus minimizing the risk of prematurity and maternal morbidity associated with interval surgery.

Introduction

An adrenal pseudocyst is a cystic lesion which arises within adrenal cortex or medulla, and is enclosed by a fibrous wall, without a recognizable true lining. ¹ These cysts are usually unilateral lesions but can be bilateral in about 10–15% of cases. ² As they are mostly non-functioning, they become symptomatic only when complicated with rupture, hemorrhage or infection. ³ In 1670, Greiselius from Vienna removed the first adrenal cyst and it was first documented by Doran in 1908. ⁴

An adrenal pseudocyst presenting as an acute abdomen in pregnancy offers a diagnostic and therapeutic dilemma. Here we describe a 26-year-old woman who presented with an acute abdomen at 28 weeks of gestation.

A literature review identified 19 further cases of adrenal pseudocyst in pregnancy.

Case

A 26-year-old woman in her first pregnancy presented to the Emergency Department at 28 weeks of gestation with severe left-sided upper abdominal pain. She did not report nausea, vomiting, bowel or bladder disturbances or breathlessness. On examination she had stable vital signs with pulse rate 88bpm, BP 122/78 mm Hg, respiratory rate 18/min, temperature 36.7°C, SpO₂ 98% in room air. A large mass in the left hypochondrium was palpable with left renal angle tenderness. Ultrasound of her abdomen demonstrated a well-defined, complex heterogenous left suprarenal lesion of (9.7 × 7.7 × 8.7 cm) with a peripheral hyperechoic rim. It had a central anechoic area with hyperechoic regions and no significant internal vascularity. Features were suggestive of a left adrenal adenoma with hemorrhage. Multidisciplinary team (MDT) input was sought. Laboratory tests including full blood count, renal function and liver function were done and were normal. A morning serum cortisol was normal at 1103 nmol/L (third trimester specific reference range 331–1380 nmol/L),⁵ as were 24 h urine vanillylmandelic acid and urinary metanephrine. Other investigations including adrenocorticotropic hormone, testosterone, DHEAS and aldosterone were not performed as the she did not have clinical features of a functional adrenal tumour and the imaging studies were suggestive of a cystic adrenal lesion. A fetal ultrasound showed normal fetal growth, liquor, and Doppler parameters with effective cervical length of 2.1 cm.

MRI (Figure 1) demonstrated a well-defined 10 × 9 × 8 cm suprarenal complex cystic lesion with intralesional altered signal. There was evidence of mass effect on the left kidney and distal pancreatic body. Inflammatory fat stranding in the left perinephric space with mildly thickened perirenal fascia was noted. There was no infiltration to adjacent structures and the features were suggestive of a left adrenal hemorrhagic pseudocyst.

Figure 1.

(a): Coronal section of abdomen on T2W MRI TRUFI image showing the complex heterogenous lesion (arrow) in left supra-renal region with hyperechoic rim and central anechoic and hyperechoic tissue. (b) MRI T2W HASTE sequence image of axial section of abdomen showing adrenal cyst (star).

The patient was in severe pain which was not relieved with oral analgesics (paracetamol). A trial of conservative management with parenteral analgesics was initiated, with emergency surgical intervention as a plan if conservative management was unsuccessful. She was monitored in the high dependency unit. Her pain improved with parenteral analgesics and supportive management. She was discharged on oral paracetamol on day 5.

She was reviewed regularly after discharge with monitoring of vital signs, laboratory parameters and fetal growth. She had occasional episodes of mild abdominal pain which responded to oral analgesia. A decision for elective caesarean section at 37 weeks was made after discussion with the patient, in view of breech presentation. This was performed under general anaesthesia, and a healthy female baby of 2.9 kg with normal APGARs was born. This was immediately followed by laparoscopic left adrenalectomy (Figure 2). The patient had an uneventful post-operative period and was discharged after 4 days. Histologic examination showed a hemorrhagic adrenal pseudocyst, components of chronic inflammation and fibrosis in the wall and an attenuated adrenal gland cortex. There was no evidence of malignancy.

Figure 2.

Intraoperative image of the huge adrenal pseudocyst (star). Dissection was extremely difficult as the cyst was densely adhered to the renal capsule.

Discussion

A PubMed search was conducted with the MeSH terms “Adrenal cyst”, “Pseudocyst” and “Pregnancy” which included title and abstract. The language was limited to English. 19 cases of adrenal pseudocysts in pregnancy were identified.

Adrenal pseudocysts

Adrenal pseudocysts are rare in pregnancy and the exact incidence is not known. As per the literature, incidence of adrenal cysts has been between 0.06 and 0.18 % in the 14000 post-mortem studies in the general population.^6–8 Although pregnancy is thought to be a risk factor for adrenal hemorrhage, a causal relationship with pseudocyst formation has not been established. In non-pregnant individuals, adrenal cysts are generally small and 10–15% of cases are bilateral. ⁹ However, in pregnancy, most of the reported adrenal pseudocysts were huge (greater than 10 cm). Four cases were identified in the first trimester^8–11, 13 in the second trimester^3,9,13–22 and one at 28 weeks. ¹⁹ 14 of these were haemorrhagic and 5 were non-haemorrhagic.

The pathogenesis of pseudocysts remains unclear but is usually secondary to repeated insults including trauma, infection, bleeding or hypoxia-mediated cystic degeneration.^23,24 Most adrenal pseudocysts are benign (93%). Malignancy occurs in about 7% and the risk of malignancy has been positively correlated with the size of the pseudocyst, especially if the pseudocyst is more than 6 cm in its greatest dimension. ²⁵

In general, adrenal pseudocysts are asymptomatic, contributing to 5.7% of all newly discovered adrenal incidentalomas. ²⁶ Symptoms are related to the size and position of the lesion, most commonly abdominal pain due to compression of surrounding structures, gastrointestinal disturbance, shortness of breath, hypertension or fever/chills due to superimposed infection. The most common sign is a palpable tender mass in the upper abdomen. Acute abdomen and shock may be present with haemorrhage or rupture of the adrenal cyst.^27,28

It is likely the acute symptoms described in this case were due to intracystic haemorrhage. Papaziogas et al. proposed that cyst rupture and haemorrhage during pregnancy may be due to oestrogen-mediated relaxation of cyst wall and rapid growth of lesions. Pressure from the enlarged uterus may also lead to symptoms. ³

Investigations

Essential investigations when a pseudocyst is identified are to look for hormonal excess and malignancy. Pheochromocytoma should be investigated with plasma or 24-h urine metanephrines. Glucocorticoid excess requires biochemical tests including 24-h urine free cortisol. The preferred imaging modality for adrenal pseudocysts is computed tomography, although ultrasound and MRI can also be used, especially in pregnancy. MRI is superior for tissue characterization and can help in identifying phaeochromocytoma and adrenal cortical carcinoma (ACC) as these have specific features on the T1- and T2-weighted images.^25,29–32 18F-Fluorodeoxyglucose-Positron emission tomography (18F-FDG-PET) is a second-line investigation for ACC but is usually avoided in pregnancy.^33,34

Treatment

Several factors determine and guide the choice of treatment modality, including endocrine function, presentation and size.

En bloc excision of the cyst and adrenal gland is indicated for a lesion measuring over 6 cm in diameter, suspicion of malignancy and symptomatic cysts or presence of complications like haemorrhage, infection or rupture. Laparoscopic resection remains the preferred intervention prior to 24 weeks of pregnancy, even for large sized lesions, as this reduces the use of large incisions, minimizes bowel manipulation and decreases postoperative morbidity and hospital stay, thus leading to a rapid functional recovery.^35–37

Laparoscopic surgery is avoided in the presence of a large adrenal cortical carcinoma with local invasion of periadrenal tissue or venous thrombus, in uncorrected coagulopathy, unacceptable cardiopulmonary risk, abdominal sepsis and intestinal obstruction. ¹³ An open surgical approach is to be considered based on expertise, availability of resources and the gestational age. ³⁸

It was felt that a laparoscopic procedure in the patient described here would have been hindered by the pregnant uterus, and increased the chance of precipitating preterm labour. Aspiration of pseudocysts was proposed by Samal et al. as a modality of conservative management for hormonally inactive cysts with clear contents measuring less than 6 cm in diameter and no suspicion of malignancy, ¹⁴ but there remains a theoretical risk of precipitating a pheochromocytoma crisis, or needle tracking of malignant cells if adrenal cortical carcinoma is present.

A variety of management approaches are described in the previous published cases: 3^14,15,21 had percutaneous drainage followed by complete surgical excision, two in the antenatal period and 1 in the postpartum period. In two cases,^3,39 exploratory laparotomy was performed, followed by subsequent surgical excision. Elective antenatal surgical excision was performed in 3 women^3,17,21 and 3 underwent postnatal procedure.^12,14,18 Emergency excision in pregnancy was performed in 12 women. The indications for urgent surgical exploration were acute abdomen, bleeding with severe anemia^9,13 and worsening of symptoms after percutaneous drainage.^15,16 In the majority of above-mentioned cases, a procedure was performed by laparotomy and laparoscopic approach was adopted in 4 cases.^12,14,18,21 We adopted laparoscopic approach for cyst excision with adrenalectomy along with the caesarean section.

Obstetric outcomes are not affected by antenatal operative intervention though theoretical risk of preterm labour persists. Literature review of outcomes after antenatal surgical intervention showed there were 7 term vaginal deliveries,^{10,15,16,19–21,39} 1 caesarean section, ³ 3 terminations of pregnancy,^9,11 1 preterm delivery ¹⁷ and 1 stillbirth with preeclampsia at 34 weeks of gestation. ³ One term delivery ¹² and 2 caesarean^14,18 sections were followed by interval laparoscopic cyst excision and adrenalectomy in the postpartum period. Outcomes were unknown in 3 cases.^13,22,40

Although the optimal surgical approach for haemorrhagic adrenal pseudocyst remains controversial, not all adrenal pseudocysts in pregnancy warrant immediate surgical intervention. A multidisciplinary decision should therefore be made weighing risks of preterm labour against the risks to the mother and fetus from delaying surgical intervention.

Conclusion

Adrenal pseudocyst should be considered in the differential diagnosis of an acute abdomen in a pregnant woman. Assessment for malignancy or metastatic disease is pertinent prior to intervention decisions. As with other abdominal procedures, second trimester remains the ideal period for operative intervention. Antenatal surgical exploration does not seem to affect the mode of delivery, but precipitation of preterm labour remains a concern especially in third trimester. Although adrenal pseudocysts diagnosed during pregnancy usually require urgent surgical management, mainly because of acute haemorrhage, in stable patients with acceptable laboratory parameters and imaging findings, a conservative approach can be adopted as described in this case. Surgical excision can be planned along with delivery if the patient undergoes caesarean section or in the postpartum period (6–12 weeks) after a normal delivery. A multidisciplinary approach is essential in such pregnancies to optimize outcomes for both mother and baby.