A DIAGNOSTIC DILEMMA: MULTIPLE BRAIN RING-ENHANCING LESIONS IN A PATIENT WTH UNILATERAL HAND NUMBNESS

Abstract

SESSION TITLE: Medical Student/Resident Lung Cancer Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Brain ring-enhancing lesions (RELs) have a broad differential diagnosis including infections, demyelinating disorders and neoplastic conditions. We present a 68-year-old female with unilateral hand numbness, newly diagnosed with metastatic lung adenocarcinoma. CASE PRESENTATION: A 68-year-old Caucasian female presented with left-hand numbness and headaches for 1 month. Her past medical history includes type 2 diabetes, tracheostomy dependence secondary to chronic respiratory failure from motor vehicle accident, 112 pack-year smoking history, and unremarkable family history. CT head without contrast was obtained to evaluate left-hand numbness and no acute intracranial hemorrhage was found. Follow-up MRI brain with and without contrast revealed innumerable subcentimeter RELs throughout both cerebral hemispheres, brainstem, and cerebellum without significant surrounding edema, which was concerning for infection. She also complained of worsening shortness of breath, so CXR was obtained and showed diffuse alveolar opacities. Follow-up CT chest revealed a left lower lobe mass measuring 3.2 x 2.7cm with multiple nodules in the left hemithorax. Bronchoscopy was considered but deferred due to significant tracheal stenosis. Of note, she had a normal CXR nine months prior. Sputum cultures were positive for Nontuberculous Mycobacterium (NTM) and therapy was initiated with azithromycin, ethambutol, ciprofloxacin, and amikacin. Infectious workup was negative for HIV, Toxoplasma, Histoplasma, Blastomyces, Cysticercosis, Coccidioides, and Aspergillus. Lumbar puncture was unremarkable for infection or malignancy. Ultimately, brain biopsy was performed on the RELs for suspected infectious etiology given her lung lesions and NTM infection. Pathology returned positive for metastatic lung adenocarcinoma. DISCUSSION: The differential diagnoses for RELs include infections (bacterial, fungal, parasitic), primary neoplasms, metastatic cancers (lung, breast, skin) and demyelinating disorders (multiple sclerosis). Our patient had RELs in both white and gray matter without significant edema, which are more characteristic of infections. Brain metastasis typically presents as a solid mass with distinct borders and surrounding edema that can become a REL if central necrosis occurs. Therefore, the patient’s RELs in conjunction with her chest images and NTM positive sputum were highly suspicious for infective process. Unfortunately, ten percent of newly diagnosed non-small cell lung cancers present with brain metastases. The median time for brain metastasis to occur is 12 to 16 months. Once metastasis occurs, median survival time is about 6 months. Therefore, prompt and accurate diagnosis is crucial to survival. CONCLUSIONS: Clinicians should consider rapidly progressive lung cancer high in the differential of brain RELs despite concurrent infections. Reference #1: Sharma V, Prabhash K, Noronha V, Tandon N, Joshi A. A systematic approach to diagnosis of cystic brain lesions. South Asian J Cancer 2013;2:98-101. Reference #2: Garg R K, Sinha M K. Multiple ring-enhancing lesions of the brain. J Postgrad Med 2010;56:307-16. Reference #3: Chakraborty S (2013). Multiple Ring Enhancing Lesions in a Patient with Unilateral Limb Jerking. J Clin Case Rep 3: 304. DISCLOSURES: No relevant relationships by Priyatha Garlapati, source=Web Response No relevant relationships by Shreedhar Kulkarni, source=Web Response No relevant relationships by Diana Song, source=Web Response