The patient was a 29-year-old man with a history of two admissions for febrile syndrome in the last two years. On one occasion, in June 1999, he was diagnosed with infectious mononucleosis with positive serology for EBV (positive VCA IgG, VCA IgM and EBNA). On the other, in September 2000, after presenting with a 10-day clinical picture of fever with chills, asthenia and general malaise with persistent positive serology for EBV, and an abdominal ultrasound scan revealed splenomegaly with a hypoechoic lesion which, after responding favourably to antibiotic treatment (broad-spectrum coverage), he was discharged with a diagnosis of splenic abscess. Since then, he remained asymptomatic until he was readmitted in June 2001 with a fever of one week's duration, accompanied by chills, headache, odynophagia and weight loss, with no other accompanying symptoms. Physical examination revealed a temperature of 39ºC, general malaise, cutaneous and mucosal pallor and splenomegaly. Laboratory tests showed normocytic anaemia (Hb 11.9 g/dl, Ht 35.8% and MCV 91.8 fl), thrombopenia (44,000 platelets/mm3), normal white blood cells (7,440/mm3) with neutrophilia (77%) and left deviation (7%Cay), slightly elevated transaminases (GPT 48 IU/L) and cholestasis enzymes (GGT 88 IU/L, FA 232 IU/L). The rest of the biochemical parameters, the coagulation study and the elemental urinalysis were normal. Proteinogram, immunoglobulin determination and immunological study were normal. Various microbiological studies were performed, including serology for hepatitis viruses (A, B and C), retroviruses (HIV-1 and 2), typhoid, brucella, mycoplasma, legionella (with determination of urine antigen), herpes, CMV, and toxoplasma, which were negative. The results of EBV serology were IgG anti-VCA IgG and IgG anti-EBNA positive and IgM anti-VCA negative. The rest of the microbiological studies (blood cultures, sputum cultures and urine cultures, which included the study of mycobacteria) were negative. Imaging tests, specifically the abdominal CT scan, showed a focal splenic lesion (which was related to abscess or infarction), enlarged lymph nodes at the para-aortic level and mesenteric adenopathies. In other studies, the results (microbiological and histopathological) obtained from liver and bone marrow biopsy were negative.
Given the initial diagnostic suspicion of intra-abdominal abscess, antibiotic treatment was started with ceftazidime, metronidazole and vancomycin, with a slight clinical improvement. Subsequently, given the aforementioned history and clinical picture, and in order to rule out, among other diagnostic possibilities, a lymphoproliferative process, a diagnostic laparotomy was performed under general anaesthesia. In this intervention, a significant splenomegaly, focal thickening of the hepatic capsule of the left hepatic lobe, a small peritoneal nodule in the mesentery of the distal ileum and multiple small lymphadenopathies at the same level were found, samples were obtained from all of them and a splenectomy was performed.
Histological study of the lymph nodes indicated reactive lymphadenitis in the lymph nodes, calcified granuloma in the peritoneal nodule and no relevant findings in the sample from the left hepatic lobe. The splenectomy specimen, which weighed 442 grams and measured 15 x 11 cm in greatest diameter, had a subcapsular nodule of 2 cm in greatest diameter, homogeneous and whitish. The remaining splenic tissue was congestive in appearance and showed no pathology. Microscopic analysis revealed a proliferation of spindle and myofibroblastic cells, with positive immunohistochemical studies for actin and negative for ALK 1 and EBV, and the pathological diagnosis was inflammatory pseudotumour of the spleen. The patient evolved favourably and has remained asymptomatic ever since.