INTRODUCTION: Malignant epithelioid hemangioendothelioma (EHE) is a rare pulmonary neoplasm with approximately 50 reported cases. EHE in the lung can be a diagnostic challenge to both clinician and pathologist. Although, most patients require surgical lung biopsy, as shown in this case, a minimally invasive transbronchial biopsy can facilitate the diagnosis.
CASE PRESENTATION: 60-year-old non-smoking gentleman with history of treated latent tuberculosis infection initially presented with fatigue, abdominal distention, and portal hypertension in 2006. The patient was diagnosed with cryptogenic liver cirrhosis complicated by Budd-Chiari syndrome. A liver transplantation was recommended for his refractory liver failure. A non-contrast chest computerized tomogram (CT) performed as a routine evaluation for liver transplant in September 2006 showed numerous faint, tiny bilateral ground glass opacities and areas of atelectasis. The patient underwent orthotopic liver transplantation in November 2006. He was asymptomatic post-transplant and tolerated his immunosuppressant regimen of tacrolimus and mycophenolate mofetil, along with Sulfamethoxazole-trimethoprim and acyclovir prophylaxis for Pneumocystis Pneumonia and herpes, respectively. A post-transplant follow-up abdominal CT in June 2007 showed multiple new ground-glass nodules in both lung bases. Therefore a chest CT was done which showed numerous tiny ground glass and solid pulmonary nodules bilaterally increased in size as compared to pre-transplant CT Chest. Although, an infectious etiology was considered, the serological studies for varicella, legionella, blastomycosis, histoplasmosis, cryptococcus, aspergillus and CMV serologies were negative. Because of the presence of multiple hypo-dense lesions in the spleen in an immunosuppressed patient, a differential diagnosis of post-transplant lymphoproliferative disorder was entertained. In order to achieve a tissue diagnosis, a fiberoptic bronchoscopy with transbronchial biopsies was performed from the left upper and lower lobes where the majority of nodules were located. Histopathological examination showed bronchial mucosa and lung parenchyma with small arteries containing plugs of moderately atypical epithelioid cells consistent with a metastatic carcinoma or a vascular neoplasm. Retrospectively, the patient's explanted hepatectomy was re-evaluated histologically which showed similar findings of atypical epithelioid cells in varied formations; single, small aggregates, lining sinuses, and growing in veins. Some of these cells had intracytoplasmic lumens. These findings are consistent with EHE. Thus, the obstruction of the venous out flow of the liver (Budd-Chiari syndrome) was deemed secondary to EHE.
DISCUSSIONS: EHE can be a diagnostic challenge for clinicians because of the symptomatic similarity with other metastatic diseases. Moreover, pathological diagnosis could be difficult because of similarities to chondrosarcomas, carcinomas, benign fibrohistiocytic lesions and granulomatous diseases. Liver is the primary site of EHE. However, EHE could present as a multi-organ disease causing infrequent involvement of the lung. Pulmonary presentation of EHE commonly appears as multiple perivascular nodules with either well- or ill-defined margins. Occasionally, ground glass or airspace disease is seen. Most patients require invasive surgical procedure for tissue diagnosis. However, in the presence of diffuse pulmonary disease, a transbronchial biopsy via fiberoptic bronchoscope is adequate to provide a tissue diagnosis as seen in our case.
CONCLUSION: EHE may present as multi-organ nodular lesions mimicking clinical metastatic disease. A transbronchial biopsy, relatively non-invasive procedure, can sufficiently provide adequate diagnostic information and would limit the risk of invasive thoracic surgery.
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