Case Presentation: A 43-year-old incarcerated man presented with 2 weeks of abdominal pain associated with nausea, emesis, and constipation. He reported subjective fevers, night sweats, and a 25-pound weight loss over the past 2 months. He had a history of germ cell testicular cancer, venous thrombosis, and leprosy. His leprosy treatment was complicated by reversal reaction that was managed with prednisone and methotrexate.
On presentation he was afebrile. Abdomen was diffusely tender to palpation, distended, and guarding was present. Labs returned with WBC 10.6 k/cmm, Lipase 7 IU/L, Creatinine 1.0 mg/dL, Alkaline phosphatase 184 IU/L, Albumin 1.6 g/dL, INR 1.8, HIV Negative. CT angiogram of the abdomen and pelvis demonstrated diffuse small bowel fat stranding, mesenteric and retroperitoneal lymphadenopathy without acute bowel obstruction. Symptoms improved and he was discharged home with follow up. Interval CT scan revealed enlargement of lymph nodes, apparent involvement of the liver, and massive ascites. Exploratory laparotomy was performed. Lymph node biopsy returned with abundant yeast, a background of fat necrosis and mixed inflammation. PAS and GMS stain were consistent with Histoplasma.
Discussion: The differential diagnoses for intra-abdominal or retroperitoneal lymphadenopathy includes malignancy, lymphoma, or tuberculosis. Without further investigation into the details of the patient history, this patient was sent home with surgical follow up scheduled on a non-urgent basis. In an immunocompromised patient on prednisone and methotrexate, the differential diagnosis changes to include more rare infectious diseases including disseminated fungal infections, toxoplasmosis, leprosy, and a variety of viral infections. Lack of recognition of immunocompromised state led to a narrow differential, resulting in a delay in diagnosis and further organ involvement.
Histoplasma capsulatum, the causative agent of Histoplasmosis, is endemic to the Ohio and Mississippi River Valleys. Microconidia are inhaled into the alveoli and subsequently phagocytosed by macrophages. Microconidia then transform into yeast, proliferate intracellularly, and disseminate through the lymphatic system. In immunocompromised individuals this spread can be rapid, leading to multiple organ involvement, potential organ failure, and even death. Clinical manifestations vary depending on organ involvement. In this case, liver failure and cirrhosis as well as abdominal pain and ileus were present due to liver and abdominal lymph node involvement, respectively.
Conclusions: With the increasing volume of imaging in medicine, mesenteric lymphadenopathy is being detected more frequently. However in the appropriate clinical context, such as in this case, lymphadenopathy may be the presenting sign of a critical infection or malignancy.