CASE REPORT
A 54-year-old woman was investigated due to a history of unintended weight loss, night sweats, pruritus and epigastric pain radiating to her back. Her medical antecedents were irrelevant, besides mild smoking habits. Physical examination revealed pallor and malnutrition without further abnormalities, including palpable peripheral lymph nodes. The diagnostic workup revealed mild lymphopaenia of 760 (1,5-6,5 x 103/µL), slight increase of the α-2 fraction of the serum electrophoresis and a β-2 microglobulin of 2400 (670-2143 ng/mL); the peripheral blood and bone marrow studies were inconclusive. Abdominal CT scan (figure 1) revealed a large retroperitoneal lymph node conglomerate and a splenic nodular infiltrate.
Figure 1. Abdominal CT: transverse (left) and sagittal (right) planes. Retroperitoneal lymph node conglomerate (14 x 7,5cm) encasing the abdominal aorta and major branches; splenic nodular infiltration.
The patient was submitted to a linear endoscopic ultrasonography (EUS), showing a large retroperitoneal mass with heterogeneous echogenicity, irregular limits and overall increased vascularization; on elastography, the lesion was heterogeneously blue (hard) (figure 2 and 3).
Figure 2. Linear EUS (simple B mode and power doppler) showing a large retroperitoneal node conglomerate (14 x 7,5cm) and splenic nodular infiltration.
Fine needle aspiration (FNA) was performed (22G needle; 4 samples) under echographic guidance (figure 3). The pathological examination (figure 4) revealed multiple aggregates of large cells with enlarged nuclei, open chromatin and some evident nucleoli. The immunohistochemical study was positive for LCA, CD20 and CD30; and negative for CD3, CD138, Vimentine, MNF116 and cytokeratins AE1/AE3. These findings are consistent with the diagnosis of retroperitoneal high grade B-cell lymphoma.
Figure 3. Linear EUS with elastography software showing: large retroperitoneal node conglomerate with heterogeneous blue aspect (up) and FNA of the mass (down).
Figure 4. Histology of biopsies; A- H&E tissue cylinder showing neoplastic cells with marked anisonucleosis and irregular contouring (10x); B – H&E Neoplastic cells of increased size with irregularly and grossly distributed chromatin; nucleoli observed (40x); C – CD20 immunohistochemistry, B cell lineage (40x); D – CD30 immunohistochemistry, large anaplastic cells with membrane staining (40x).
Commentary:
Retroperitoneal malignant tumours are rare entities and account for 0,1-0,2% of all malignancies. They are classified according to their origin as: a) mesenchymal neoplasms, b) neurogenic tumours, c) germ cell, sex cord and stromal cell tumours and d) hematologic neoplasms1. Despite the overall predominance of tumours of mesenchymal origin, lymphomas are individually the most prevalent retroperitoneal tumors2. The case of this patient is illustrative of the auxiliary role of EUS in the study of these lesions. On one hand, this exam (including the use of doppler, elastography or ultrasound contrast agents) might be an important contribution to the evaluation of the morphology and local staging of these lesions. On the other hand, fine needle aspiration or trucut needle biopsies provide significant biological samples for cytological and histologic studies through a minimally invasive and safe procedure3,4.
References:
1. Rajiah P, Sinha R, Cuevas C, et al. Imaging of Uncommon Retroperitoneal Masses , RadioGraphics, 2011; 31:949–976.
2. Neville A, Herts BR. CT characteristics of primary retroperitoneal neoplasms, Crit Rev Comput Tomogr. 2004;45(4):247-70.
3. Erickson R, Tretjak Z. Clinical utility of endoscopic ultrasound and endoscopic ultrasound-guided fine needle aspiration in retroperitoneal neoplasms, Am J Gastroenterol, 1995: 1188-1194.
4. Wittmann J, Kocjan G, Sgouros S, et al. Endoscopic ultrasound-guided tissue sampling by combined fine needle aspiration and trucut needle biopsy: a prospective study, Cytopathology, 2006, 17, 27–33.
Authors:
João Pinto1, Helena Ribeiro1, Cátia Leitão1, Isabel Antunes2, Ana Caldeira1, Eduardo Pereira1
1. Gastroenterology Department, Hospital Amato Lusitano, Castelo Branco, Portugal
2- Internal Medicine Department, Hospital Amato Lusitano, Castelo Branco, Portugal