Brain Pathology Case of the Month - August 2013

Contributed by Ali Mahta, MD1#, Zhongde Du, MD4#, Ewa Borys, MD2, Bob Carter, MD, PhD3, Scott R. Vandenberg, MD, PhD2, Santosh Kesari, MD, PhD1*
1 Department of Neurosciences, Moores Cancer Center, University of California, San Diego, La Jolla, CA
      2 Department of Pathology, Neuropathology Division, University of California, San Diego, La Jolla, CA
      3 Department of Neurosurgery, University of California, San Diego, La Jolla, CA
      4 Department of Neurology, The 89th Hospital of PLA, Weifang, Shandong, China
      # co-first authors


A 78 year old right handed male presented with dysphagia particularly for liquids and dysarthria for the last four months. He was recently under evaluation for his fairly new onset anemia and renal failure in a private clinic. He denied any headaches, visual problems, fainting or any word finding difficulty. His past medical history was significant for ischemic heart disease, hypertension, bronchitis and kidney stones. The most prominent findings on physical exam were left sided lower (VIII-XII) cranial nerve palsies. Laboratory tests revealed an anemia with hemoglobin of 7.8 g/dl and a serum creatinine of 8.1 mg/dl. The Brain MRI demonstrated a left posterior fossa hyper-intense extra-axial mass extending into the left jugular foramen. (Figure 1). The differential based on the location was paraganglioma, schwannoma and meningioma. The patient underwent a sub-occipital biopsy of the lesion.


H&E stained sections showed cylindrical biopsies of paucicellular fibrous tissue and skeletal muscle infiltrated by monomorphic tumor cells with uniformly round nuclei with varyingly prominent nucleoli and scanty to moderate amounts of amphophilic cytoplasm enclosed within occasionally distinct cytoplasmic borders. (Figures 2 and 3). In some fields no neoplasm was identified and the fibrous connective tissue was dominated by multiple foreign body type giant cells and accompanying histiocytes. The tumor cells were universally strongly positive for CD138 (Figure 4). EMA was positive in a significant minority of tumor cells. A CD20 stain labeled only a few scattered cells in the mass. A Chromogenic in situ hybridization (CISH) preparation for determination of kappa and lambda expression was performed which showed lambda expression (blue stain) and kappa expression (red stain) (Figure 5). What is the diagnosis?


International Society of Neuropathology