A non-resolving splenic ‘abscess’ in an elderly male – An unusual manifestation of splenic lymphoma

Case history

A 74-year-old man presented with left hypochondrial pain and low-grade fever for 10 days. He was not diabetic. Clinically, he was pale but had no lymphadenopathy. Abdominal examination revealed tender splenomegaly. There was no clinical or radiological evidence of pleural effusion or ascites. A full blood count showed anaemia (Hb 59 g/L) and leucocytosis (14 × 10⁹/L) with no parasites seen in the peripheral smear. Biochemical workup showed hypoalbuminaemia (27 g/L) with other parameters in the normal range. An abdominal ultrasound scan showed a hypoechoic area with internal moving echoes in the spleen suggestive of an abscess. Contrast-enhanced CT scan revealed a hypodense non-enhancing lesion of 8.4 ×6.2 cm (Figure 1(a)). Drainage and appropriate antibiotic therapy failed to eliminate the abscess. At operation, the spleen was found to be densely adherent to adjacent structures and diaphragm. Hence, a splenotomy alone was performed to evacuate the pus, and tissue from the wall of the cavity was subjected to histopathological examination, which showed focal preservation of splenic white pulp with effacement of the majority of splenic germinal centres with lymphomatous cells. The red pulp was diffusely infiltrated as well. On immunohistochemistry, the lymphomatous cells were positive for CD20 and negative for CD3, CD5, CD10, TdT and cyclin 1 (Figure 1(b) and (c)). Subsequently, bone marrow aspiration showed infiltration of the marrow by non-Hodgkin’s lymphoma. Chemotherapy was deferred because of the patient’s poor status. OPEN IN VIEWER

Discussion

Splenic abscess, on account of its rarity, is a difficult clinical diagnosis. The absence of known risk factors such as bacterial endocarditis, an immunocompromised state, or previous trauma, makes it even more difficult. ¹ Splenomegaly associated with pain in the left upper quadrant and fever are classic features. A splenic abscess may arise from secondary infection of a hydatid cyst or an infarct particularly with sickle cell disease (and especially in malarial endemic areas where giant splenomegaly is common). It may also develop in amoebiasis, brucellosis or leptospirosis or from direct spread of pancreatitis or a perforated gastric ulcer. Rarely, it arises secondary to infection in a necrotic tumour.

Ultrasound helps in diagnosis through aspiration and cytology and also in therapeutic drainage. ² The abscess appears hypoechoic on ultrasound, but it may not be possible to differentiate it from splenic lymphoma. CT, if available, may more accurately define the location and extent of the abscess as well as defining the presence of subcapsular and perisplenic pathology. ³ Antibiotic therapy alone is recommended for lesions < 4 cm in diameter, but percutaneous drainage for lesions larger, and open drainage where aspiration failed. ⁴ Splenotomy may be a safer option than splenectomy because dense adhesions usually prevent easy mobilisation of the adherent spenic capsule. ¹

Primary splenic lymphoma is rare and constitutes less than 1% of non-Hodgkin’s lymphomas. Although bone marrow involvement is quite common, spillover into peripheral blood is less often seen. ⁵ Old age, anaemia, hypoalbuminemia, thrombocytopenia and elevated lactate dehydrogenase levels are indicators of poor prognosis. ⁵