Introduction

Adrenal myolipoma is an exceptionally rare benign mesenchymal tumor composed of mature adipose tissue and smooth muscle elements. Although most adrenal tumors encountered in clinical practice are adenomas, pheochromocytomas, or adrenal cortical carcinomas, myolipoma remains an uncommon pathological entity that can present diagnostic and therapeutic challenges. The increasing use of advanced imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) has led to a higher incidence of incidental detection of adrenal masses, including rare tumors like adrenal myolipoma.

Laparoscopic resection has emerged as the gold standard for the management of most benign adrenal lesions. The minimally invasive approach offers excellent visualization, reduced postoperative pain, shorter hospital stay, faster recovery, and superior cosmetic outcomes compared to conventional open surgery.

Understanding Adrenal Myolipoma

Myolipoma is a benign soft tissue tumor characterized by an admixture of mature fat cells and well-differentiated smooth muscle fibers. While myolipomas are more commonly found in the retroperitoneum, pelvis, and abdominal cavity, occurrence within the adrenal gland is exceedingly rare.

Most adrenal myolipomas are non-functioning tumors and are often discovered incidentally during imaging studies performed for unrelated conditions. Histologically, these tumors demonstrate no cellular atypia or malignant potential, making complete surgical excision curative in the majority of cases.

Clinical Presentation

Patients with adrenal myolipoma may remain asymptomatic for years. Symptomatic presentations are generally related to tumor size and mass effect on surrounding structures.

Common symptoms include:

• Dull flank pain
• Upper abdominal discomfort
• Back pain
• Sensation of abdominal fullness
• Nausea
• Incidental adrenal mass detected on imaging

Large tumors may occasionally compress adjacent organs, resulting in gastrointestinal or urinary symptoms. Functional endocrine abnormalities are uncommon but should always be excluded during preoperative evaluation.

Diagnostic Evaluation

Hormonal Assessment

Every patient presenting with an adrenal mass should undergo a thorough endocrine workup to rule out hormonally active lesions.

Investigations may include:

• Serum cortisol levels
• Dexamethasone suppression test
• Plasma metanephrines
• Catecholamine levels
• Serum aldosterone
• Plasma renin activity

Radiological Imaging

Computed Tomography (CT Scan)

CT imaging often demonstrates a well-circumscribed adrenal mass containing significant fatty components. The presence of mixed-density areas corresponding to adipose and smooth muscle tissue may suggest the diagnosis.

Magnetic Resonance Imaging (MRI)

MRI provides superior soft tissue characterization and helps differentiate myolipoma from other fat-containing adrenal lesions.

Differential Diagnosis

The differential diagnosis includes:

• Adrenal myelolipoma
• Lipoma
• Liposarcoma
• Angiomyolipoma
• Adrenal adenoma with fatty degeneration
• Retroperitoneal sarcoma

Definitive diagnosis is usually established through histopathological examination after surgical excision.

Indications for Surgical Resection

Although adrenal myolipomas are benign, surgical intervention may be recommended in the following situations:

• Tumor size greater than 4–6 cm
• Progressive enlargement on serial imaging
• Symptomatic lesions
• Uncertain diagnosis
• Suspicion of malignancy
• Compression of adjacent structures

Laparoscopic adrenalectomy is particularly advantageous for benign and moderately sized tumors.

Laparoscopic Surgical Technique

Patient Positioning

The patient is positioned in a lateral decubitus position with the affected side elevated. This allows gravity-assisted retraction of abdominal organs and optimal exposure of the adrenal gland.

Port Placement

Typically, three to four laparoscopic ports are inserted strategically to provide access for the camera and operating instruments.

Exposure of the Adrenal Gland

The procedure begins with careful mobilization of adjacent structures:

For right-sided lesions:

• Mobilization of the liver
• Exposure of the inferior vena cava

For left-sided lesions:

• Mobilization of the splenic flexure
• Reflection of the spleen and pancreatic tail

Identification of Adrenal Vein

Early identification and secure control of the adrenal vein are crucial steps that minimize intraoperative blood loss and facilitate safe dissection.

Tumor Dissection

Meticulous dissection is performed using advanced energy devices. The tumor is separated from surrounding tissues while preserving adjacent vital structures.

Specimen Retrieval

The resected specimen is placed inside an endoscopic retrieval bag and extracted through a slightly enlarged port site, preventing tumor spillage and maintaining oncological principles.

Advantages of Laparoscopic Resection

Compared to open surgery, laparoscopic adrenalectomy offers numerous benefits:

• Smaller incisions
• Reduced postoperative pain
• Minimal blood loss
• Lower wound complication rates
• Shorter hospitalization
• Faster return to daily activities
• Improved cosmetic results
• Enhanced visualization of retroperitoneal anatomy

These advantages have made laparoscopy the preferred treatment modality for benign adrenal tumors worldwide.

Histopathological Findings

Microscopic examination typically reveals:

• Mature adipocytes
• Interlacing bundles of smooth muscle fibers
• Absence of cellular atypia
• No evidence of necrosis
• No malignant transformation

Immunohistochemical studies may demonstrate positivity for smooth muscle markers such as smooth muscle actin (SMA) and desmin, confirming the diagnosis.

Postoperative Care

Postoperative management includes:

• Early ambulation
• Pain control
• Monitoring of vital signs
• Assessment of adrenal function when indicated
• Gradual resumption of oral diet

Most patients can be discharged within 24 to 72 hours following uncomplicated laparoscopic surgery.

Prognosis

The prognosis following complete laparoscopic excision of adrenal myolipoma is excellent. Recurrence is extremely rare, and malignant transformation has not been documented in the literature. Patients generally experience complete resolution of symptoms with long-term disease-free survival.

Conclusion

Laparoscopic resection of adrenal myolipoma represents a safe, effective, and minimally invasive treatment strategy for this rare benign adrenal neoplasm. Accurate preoperative assessment, careful surgical planning, and adherence to advanced laparoscopic principles enable successful management with minimal morbidity. As surgical expertise and imaging technologies continue to evolve, laparoscopy remains the preferred approach for the treatment of most benign adrenal tumors, providing outstanding clinical outcomes and enhanced patient recovery.