149 - Emergency Steroid Treatment of Superior Vena Cava Syndrome Secondary to Malignant Mediastinal Mass Resulting In Diagnostic Uncertainty Due to Pre-Biopsy Administration

Malignant mediastinal masses, most commonly caused by lymphomas and germ cell tumors, can result in superior vena cava syndrome (SVCS) due to compression of the superior vena cava. Clinical features include chest pain, cyanosis, dyspnea, and swelling of the face, neck, and upper torso. SVCS is a medical emergency, and treatment options include rapid high dose irradiation, chemotherapy, and corticosteroids. However, giving emergent corticosteroids to a patient prior to obtaining a biopsy can be challenging as these can affect the diagnostic accuracy of the biopsy by distorting cellular morphology.

Objective:

Our aim is to describe the distinctive case of a 17 year old boy with a mediastinal mass who presented with SVCS that was emergently treated with corticosteroids prior to a biopsy, resulting in diagnostic uncertainty.  

 

Design/Methods:

Single subject case report


Results:

A 17 year old boy who presented with SVCS due to a mediastinal mass was rapidly started on dexamethasone due to worsening clinical features and received three doses prior to a diagnostic biopsy. Results were delayed due to difficulty in reading the slide specimens, however the initial diagnosis resembled metastatic embryonal carcinoma, and so a generic chemotherapy therapy regimen was started consisting of ifosfamide, etoposide, and cisplatin (VIP) via ACGT1532 to cover high grade carcinomas, germ cell tumors, and classic Hodgkin lymphoma. He received one course of VIP however he required tumor debulking due to persistent SVC compression. He started a second cycle of chemotherapy with bleomycin, etoposide, and cisplatin (BEP) per AGCT1532 however, again, had poor response. Next generation sequencing eventually revealed an EML4:ALK fusion which is often associated with anaplastic large cell lymphoma (ALCL), however he was found to be CD30 negative. Due to poor response despite multiple lines of therapy, he began treatment for what was now presumed to be ALCL. He received triple intrathecal chemotherapy once followed by treatment per ANHL12P1 with crizotinib, dexamethasone, ifosfamide, methotrexate, cytarabine, and etoposide with good response.

Conclusion(s):

This case report details the adverse effects on pathological diagnosis from treatment with corticosteroids. This patient’s poor response after multiple lines of chemotherapy may be due to diagnostic uncertainty secondary to imperative emergent corticosteroid treatment prior to his biopsy. Providers should be aware of the potential adverse effects of corticosteroids on biopsy results, which may lead to misdiagnosis, delays in management, and incorrect treatment regimens.