Right adrenal giant cystic pheochromocytoma: A case report

Abstract

A 78-year-old woman was referred to our institution for evaluation and treatment of a mass on her right adrenal gland measuring 12 × 11 × 10 cm. Twenty-four–hour urine analysis revealed a total metanephrine level over 3 times the upper limit of normal. Scintigraphy using ¹²³I-metaiodobenzylguanidine was positive. The mass was resected en bloc by laparotomy after a laparoscopic attempt was unsuccessful. Histopathologic examination revealed a pheochromocytoma of the right adrenal gland, weighing 576 g. The Grading System for Adrenal Pheochromocytoma and Paraganglioma score was 6, and the histology of the tumor was a moderately differentiated type.

Highlights

• •A giant pheochromocytoma is a rare entity.
• •All pheochromocytoma need to be treated as a malignant tumor.
• •Histopathological findings should be evaluated by GAPP score.

1. Introduction

Pheochromocytoma is a neuroendocrine tumor of the adrenal medulla, involving cells that produce catecholamines. It is a rare entity. Some authors report that approximately 10 individuals in 1 million are diagnosed with pheochromocytoma each year,^1,2 and it is thought that only 0.5% of hypertension is caused by pheochromocytoma.³ Considering the rarity of this tumor, a large pheochromocytoma with a cystic lesion is even more rare. Cystic variants of pheochromocytoma are believed to manifest when hemorrhage, degeneration, or necrosis occurs within the solid mass of the tumor.³ Although clinicians have to consider all pheochromocytomas as potentially malignant, the incidence of malignancy for all adrenal cysts is reportedly only 7%.⁴ Although there is no definition of a “large” or “giant” pheochromocytoma, we searched PubMed for descriptions of lesions with a diameter of 10 cm or more and found approximately 100 cases as of December 2022. We present our experience with a patient who presented with a right adrenal giant cystic pheochromocytoma, treated safely using laparotomy after conversion from laparoscopic surgery.

2. Case presentation

A 78-year-old woman visited an outside hospital with a 1-week history of mild left back pain. Contrast-enhanced computed tomography revealed a giant mass with solid and cystic components involving the right adrenal gland and measuring 12 × 11 × 10 cm (Fig. 1A and B). The patient was referred to our institution for further evaluation and treatment.

Fig. 1.

A, B: Contrast enhanced computed tomography showing a mass with a cystic lesion in the right adrenal gland measuring 12 × 11 × 10 cm; contrast effect is observed in the solid component of the lesion C, D: ¹²³I- metaiodobenzylguanidine scintigraphy shows uptake only in the solid portion of the mass.

The patient had a history of hypertension for more than 20 years, but there was no family history of pheochromocytoma or paraganglioma. Her blood pressure was 130/60 mm Hg and was well controlled on amlodipine. We initially suspected a pheochromocytoma or adrenocortical carcinoma. Her serum adrenaline and noradrenaline levels were high, and her dehydroepiandrosterone sulfate (DHEAS) level was normal (21 ng/mL). Biochemical testing on a 24-h urine sample revealed elevated total metanephrines (10.3 mg/day), metanephrine (1.58 mg/day), and normetanephrine (8.72 mg/day); these values were more than 3 times the upper limit of normal. Scintigraphy using ¹²³I- metaiodobenzylguanidine was positive in the solid portion of the mass and there were no other positive lesions (Fig. 1C and D).

The patient underwent 10 days of preoperative treatment with cardenaline (≤9 mg/day) and administered saline (1.5 L/day) one day before surgery. We attempted to remove the mass by a laparoscopic approach, but it was difficult to separate the tumor from the inferior vena cava. We converted to open surgery via a vertical midline incision. The right liver lobe needed to be pushed to the midline to access the tumor (Fig. 2), but the procedure went well with no complications. The operative time was 7 hours, and the estimated blood loss was 510 mL. There were no postoperative complications, and the patient was discharged on postoperative day 10. Histopathologic examination revealed a pheochromocytoma of the right adrenal gland, weighing 576 g (Fig. 3A and B). Hematoxylin and eosin staining revealed a Zellballen pattern, and immunostaining was positive for chromogranin A (Fig. 3C and D). The Grading System for Adrenal Pheochromocytoma and Paraganglioma (GAPP) score was 6 (total maximum score, 10), and the histologic type was moderately differentiated. Genetic screening was not performed. One year after surgery, the patient has shown no evidence of recurrence.

Fig. 2.

2: Intraoperative photograph taken after removing the giant pheochromocytoma shows displacement of the right liver lobe to the midline.

Fig. 3.

A, B: The resected tumor measures 11 × 10 × 8.5 cm; the cut specimen reveals necrosis, liquidation, and blood in the cystic portion of the lesion C: Hematoxylin and eosin staining shows a Zellballen pattern D: Immunostaining is positive for chromogranin A throughout the mass.

3. Discussion

Giant pheochromocytoma is a very rare entity. A PubMed search filtered by the words “pheochromocytoma” and “giant or large” in the title or abstract yielded a total of 452 results as of 2022. However, since the use of the “large” dose not provide a clear definition of size, and there are many cases less than 10 cm, we have diceded to use only the “giant” for our search. Then, we excluded reports that did not describe tumor size in abstract, and we included those that described pheochromocytomas larger than 10 cm. A total of 42 reports (describing 43 patients) were eligible for inclusion in our review. Each year, there are approximately 1–5 case reports describing this entity. In the last 3 years (2019–2021), 5 patients were reported.3 This result reinforces the rarity of giant pheochromocytoma. Although pheochromocytomas of the right adrenal gland reportedly tend to be larger than those of the left adrenal gland, our literature review of large pheochromocytomas found 19 patients with right-sided lesions and 24 with left-sided lesions. We therefore purport that it remains unknown whether the side of the pheochromocytoma makes a difference in its size.

In general, large adrenal tumors raise concern for the possibility of malignancy; the same holds true for pheochromocytomas. Patients with recurrent pheochromocytomas typically have larger lesions at diagnosis than those who do not experience recurrence. As adequate resection margins are essential for potentially malignant tumors, we used a simulation of surgery to prepare for our patient's procedure, and we considered the possibility of performing a combined resection with other organs—including the liver, kidney, and inferior vena cava—in case of tumor invasion. Although this was not ultimately necessary for our patient, it is crucial to consult with other surgeons before beginning surgery.

Because pheochromocytomas need to be treated as potentially malignant tumors, assessment using GAPP and lifetime follow up are needed for our patient.⁵ Her GAPP score was 6 points, corresponding to a moderately differentiated group of lesions; these tumors tend to recur more often than those in the well-differentiated group. To our knowledge, there are no case reports of giant pheochromocytoma that include the GAPP score.

Institutional review board approval

N/A.

Informed consent

Informed consent was obtained from the patient.

Study/trial registration

N/A.

Declaration of competing interest

The authors have no conflicts of interest to declare.