Presentation
Newly diagnosed hypertensive with long-standing epigastric pain associated with nausea & vomiting. There is also a history of generalized fatigability, palpitations and headache.
Patient Data
Large heterogeneous mass in the left hypochondrium with mixed solid and cystic components and mild internal vascularity, measuring about 13 x 11 cm.
Large non-calcified heterogeneous left hypochondrial mass having enhancing solid and cystic components, some with fluid-fluid levels. It is inseparable from the pancreas and is displacing the spleen anteriorly and left kidney inferiorly. Left adrenal is not confidently identified. Multiple small calcified gallstones without any CT features of acute cholecystitis.
Complex left upper quadrant lesion measuring about 14 x 11 x 10.5 cm, showing peripheral solid components, central multiple heterogeneous cystic areas, some of which show fluid-fluid levels, and T1 hyperintense areas suggestive of hemorrhage. Solid components show enhancement and diffusion restriction. The lesion is inseparable from the pancreatic tail and is displacing the spleen anteriorly and the left kidney inferiorly. Left adrenal gland is not clearly identified. Multiple intraluminal defects seen in the gallbladder (gallstones) without any features of acute cholecystitis.
Large MIBG-avid mass in the left hypochondrium showing inhomogeneous radiotracer concentration, i.e. areas of increased radiotracer concentration, surrounding areas of poor radiotracer uptake, probably secondary to degeneration.
Case Discussion
Based on the imaging findings, a preliminary diagnosis of left adrenal pheochromocytoma was made. Possible differentials included paraganglioma, ganglioneuroma and gastrointestinal neuroendocrine tumor.
The patient went on to have robot-assisted laparoscopic left adrenalectomy.
Preoperative laboratory investigations: plasma metanephrine >5000 ng/l (reference range: <90), and normetanephrine >5000 ng/l (reference range: <129).
Pathology report:
Size: 20 x 14.0 x 10.0 cm. Weight: 813 grams. Lymphovascular, capsular and adjacent organ invasion: not identified. Margins: free of tumor. Mitosis: > 3/10 HPF. Regional lymph node status: No lymph node submitted. Distant metastasis: not applicable. pTNM stage (by the 8th edition of AJCC): pT2NxMx.
The adrenal tumor shows classical morphology of pheochromocytoma with extensive central necrosis. The residual viable tumor show atypical worrisome features consistent with malignancy, based on PASS and GAPP pathological grading system. Based on the PASS score, the tumor can accrue up to 17 points: mitosis >3/10 HPF: (2), atypical mitosis: (2), necrosis: (2), diffuse sheats (large nests/diffuse growth): (2), cellular spendling: (2), high cellularity: (2), hyperchromasia: (1), marked nuclear pleomorphism: (1), celluar monotony: (2) and capsular invasion: (1). According to the GAPP scoring system the tumor corresponds to poorly differentiated type (score=10): Histological pattern: Large and irregular cell nest: (1), pseudo-rosette: (1), high cellularity: (2), Comedo necrosis: (2), Capsular Invasion: (1), Ki-67: (>3%): (2), catecholamine type: norepinephrine: (1).
Diagnosis: pheochromocytoma with malignant features.
Two weeks after the left adrenalectomy: plasma metanephrine <50 ng/l and normetanephrine 151+ ng/l.