Pancreatic neuroendocrine tumor with solitary splenic metastasis and synchronous renal cell carcinoma: A rare case report

Abstract

Synchronous pancreatic neuroendocrine tumors and renal cell cancer are extremely rare. Von-Hipple-Landau syndrome is a major association. A 43-year-old male patient with left upper quadrant pain and significant weight loss was diagnosed with a synchronous pancreatic tail neuroendocrine tumor with solitary splenic metastasis and a clear-cell renal cell carcinoma of the left kidney. Sonography and a computed tomography scan of the abdomen showed a complex exophytic left renal mass and a necrotic lesion limited to the spleen. Although not apparent on preoperative imaging, distal pancreatic mass was also discovered intraoperatively. Subsequently, left radical nephrectomy, splenectomy, and distal pancreatectomy were performed, and the synchronous primaries and splenic metastasis were confirmed histopathologically. This case is unique in that it demonstrates multiple extremely rare events occurring simultaneously, namely pancreatic and kidney primaries, as well as solitary splenic metastasis.

Keywords: Computed tomography; Pancreatic neuroendocrine tumor; Renal cell carcinoma; Solitary splenic metastasis; Synchronous tumors; Von-Hippel-Lindau.

Fig. 1

Transverse Gray (A) and doppler (B) mode sonography of the spleen and longitudinal Gray (C) and doppler (D) mode sonography of the left kidney: A relatively hyperechoic splenic hilar lesion (white arrows in A) with heterogeneous central echo-content. Upper pole of left kidney (k) is seen in the left lower corner of the image. There is paucity of flow in the center of the lesion (B). The renal lesion is heterogeneously hypoechoic and deforms the left renal contour (black arrows on C). Although there is some bowel gas shadowing on the color doppler (D), the visible part of the lesion shows significant flow (black arrows in D).

Fig. 2

Triphasic abdominal CT in pre-contrast (A, D), arterial (B) and portal (C) phases at the level of the spleen: A 9 × 6.6 × 8 cm (AP x TR x CC) irregularly marginated splenic hilar lesion (white arrows) seen. It is only faintly visualized in the precontrast (A) phase, but shows circumferential rim enhancement and some dispersed central enhancing regions in the arterial phase (B) which subsequently fade in the portal phase (C). On the same planes, there is a 2.8 × 3 × 3.5 cm (AP x TR x CC) left posterosuperior relatively well-defined round or ball shaped renal contour deforming and heterogeneously enhancing renal mass (black arrowheads). Incidental note is made of a small left lower pole stone without causing calicyal dilation (black arrow D).

Fig. 3

Reconstructed coronal (A) and sagittal (B) portal phase CT: The splenic lesion is causing splenomegaly, which measures 17 cm. The sagittal view depicts the relative positions of the splenic and left renal masses.

Fig. 4

Cut sections of the left kidney (A) and spleen (B): The left kidney shows a circumscribed mid pole mass (arrowhead in A). (B) reveals a large gray white solid area with cystic and necrotic foci within the spleen.

Fig. 5

Photomicrographs at low (A, C, E) and high (B, D, F) power magnifications of the left kidney (A and B), pancreatic (C and D), and splenic (E and F) specimens: A low-power (2x) photomicrograph of the left kidney shows a circumscribed mass with adjacent normal renal parenchyma (arrow in A). At a higher power (20x), the left kidney shows clear cells with small nucleoli arranged in tubes with fine fibrovascular septae, which is consistent with clear cell renal cell carcinoma. The pancreatic tail mass at 20x magnification reveals monomorphic cells with stippled chromatin arranged in an organoid pattern adjacent to the pancreatic duct marked with an arrowhead, indicating features consistent with NET. At 40x magnification, D depicts the intermingled areas of oncocytic NET in the pancreas, which are composed of relatively monotonous cells with central nucleoli and ample eosinophilic granular cytoplasm. At 10x magnification, microscopy reveals a circumscribed splenic mass consisting of sheets of polygonal cells with ample eosinophilic cytoplasm, alongside normal splenic tissue visible on the left. High-power (40x) magnification of splenic mass composed of similar cells as depicted on D, with more dyscohesive growth.