Endoscopic ultrasound elastography to diagnose sarcoidosis.

A 54-year-old man presented with a 3-month history of sharp intermittent lower abdominal pain along with decreased oral intake, nausea, and a 13.6 kg weight loss. Laboratory results were significant for normocytic anemia (hemoglobin-12.7 g/dL) and hypercalcemia (serum calcium-12.2 mg/dL). Abdominal ultrasound showed a well-defined heterogeneous complex solid mass at the level of the pancreatic head measuring 4.6 cm × 3 cm × 4 cm in size. Subsequently, a computed tomography (CT) abdomen/pelvis was obtained showing lymphadenopathy in the portacaval lymph node chain (5.7 cm × 4.2 cm × 6.4 cm), peripancreatic lymph node chain anterior to the pancreatic head (5.2 cm × 3.8 cm × 5.6 cm), and within the porta hepatis lymph node chain (2.1 cm × 1.4 cm × 2.2 cm) [Figure 1]. Further, blood workup showed an angiotensin-converting enzyme (ACE) level of 144 unit/L (range 8-52 unit/L), and serum protein electrophoresis showed prominent polyclonal hypergammaglobulinemia.

Figure 1

CT abdomen: Intra-abdominal lymphadenopathy (arrows)

Endoscopic ultrasound (EUS) [PENTAX EG-3870UTK Ultrasound Video Gastroscope, HITACHI Hi VISION 900 (HV900) Ultrasound Scanner system] was performed to evaluate the intra-abdominal lymphadenopathy and adjacent structures. EUS showed a large sized (35 mm × 39 mm), well-circumscribed homogeneous appearing, round, peripancreatic lymph node [Figure 2]. Using EUS elastography, features of the enlarged lymph node showed a mixed, predominantly green pattern, with an elastography score of 3 [range 1 (soft)-5 (hard/solid)] [Figure 3]. Fine-needle aspiration (FNA) was performed using a 22-gauge ProCore needle (Cook Endoscopy, Winston-Salem, NC, USA). There was another large, 36 mm × 44 mm, retroperitoneal lymph node near the body of the pancreas. Other enlarged lymph nodes were seen in the porta hepatis region, the celiac area, the paraesophageal area, and the aortopulmonary window. Elastography of these additional lymph nodes showed similar mixed, predominantly green pattern. FNA results showed a naked granuloma with a cluster of epithelioid histiocytes on Diff-Quik stain [Figure 4], one multinucleated giant cell on Papanicolaou (Pap) stain [Figure 5], and a hyalinizing naked granuloma with two multinucleated giant cells (one with an asteroid body) on cellblock hematoxylin and eosin (H&E) stain [Figure 6]. Special stains for acid-fast bacilli and fungi were negative, along with normal flow cytometry. Overall findings were consistent with sarcoidosis.

Figure 2

EUS: Round homogeneous peripancreatic lymph node

Figure 3

Lymph node elastography: A mixed, predominantly green pattern

Figure 4

Diff-Quik stain: Epithelioid histiocytes

Figure 5

Pap stain: A multinucleated giant cell

Figure 6

H and E stain: Giant cells (arrows) and asteroid body (circled)

Sarcoidosis is a granulomatous disorder of unknown etiology affecting multiple organs. Diagnostic criteria includes clinicoradiological findings and noncaseating granulomas with no alternative diagnosis.[1] In patients with mediastinal lymphadenopathy, diagnosis of sarcoidosis using EUS with FNA has a sensitivity and specificity of 89% and 96%, respectively.[2] We used EUS elastography to further characterize the targeted lymph node. EUS elastography shows differences in tissue hardness based on tissue elasticity. Blue colors are considered “harder” possibly malignant tissue versus mixed green–yellow–red hues being “softer” possibly benign tissue.[3] A previous case using EUS elastography further characterized a hepatic lesion from sarcoidosis with a predominant blue pattern.[4] Another case of a cervical lymph node had features highly suspicious for malignancy with a predominant blue pattern on EUS elastography; however, the pathology was consistent with sarcoidosis.[5] In contrast, our case showed a mixed, predominantly green pattern, which is more consistent with benign tissue being sarcoidosis. An elastographic score of 3 is consistent with a mixed pattern of hard and soft tissues “honeycombed pattern,” which may make the interpretation difficult. An elastography score can range 1-5, which is consistent with soft to hard/solid tissue, respectively.[6] In summary, EUS elastography can be used as an adjunct to characterize enlarged lymph nodes associated with sarcoidosis or other disease processes. Differing elastographic patterns have been seen in evaluation of sarcoidosis, and further studies are needed to define a set characteristic pattern for sarcoidosis using elastography.

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Conflicts of interest

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