S62 Am J Clin Pathol 2018;149:S54-S63 DOI: 10.1093/AJCP/AQX119 © American Society for Clinical Pathology AJCP / Meeting AbstrActs In young patients, 81%, 38%, 87%, 7%, 40%, and 67% of tumors were positive for CK7, CK20, CK19, NCAM, N-Cadherin, S100P, compared to 95%, 32%, 95%, 0%, 52%, and 38% in the control group, respectively. Diffuse strong expression of p53 was observed in 33% of tumors of the young (vs 52% in control group). All tumors had intact expression of mismatch repair proteins. Mean fol- low-up time was 2.8 years (range 0.25–11 years). Fourteen (70%) patients died of disease, and the fve-year survival rate was 25%. Conclusion: Cholangiocarcinoma of the young is highly aggressive, most commonly presenting at advanced stage and with high histologic grade, and is hence associated with poor survival. It is more commonly intrahepatic than cholangiocarcinoma in older adults, but is morpho- logically and immunohistochemically similar to it, except for increased expression of S100P and decreased expres- sion of p53. 145 Giant Cell Tumors of Bone With Pulmonary Metastasis Shenon Sethi, Vijaya Reddy, MD, Pincas Bitterman, MD, Paolo Gattuso, MD; Rush University Medical Center, Chicago, IL Introduction: Giant cell tumor of bone (GCTB) is a rel- atively rare, benign, but locally aggressive primary intra- medullary tumor. Pulmonary metastasis is seen in 2%-3%. This is a retrospective review of the clinical presentation, long-term outcomes, and treatment of GCTB with pul- monary metastasis. Methods and Materials: Institutional surgical pathol- ogy records from 1993 to 2015 were searched for primary GCTB. Results: A total of 98 patients with GCTB were identifed with a mean age of 38 years and male to female ratio of 1.6:1. Of these, 30 developed local recurrence, and four (two men, two women, mean age 35 years) developed lung metastasis. The tumor locations included a case each of femur, tibia, T12 vertebra, and ischium. All four patients underwent intralesional curettage/subtotal resection. Lung metastases were detected at a mean of 79 months after the treatment of bone lesions. Two patients had local recurrences prior to and one had recurrence following pulmonary metastasis. The pulmonary metastases were managed by wedge resections in all cases. The recurrences were treated by surgery (1/3), surgery with methotrexate (1/3), and radiation and denosumab (1/3). All patients with metastatic disease were alive and healthy at a mean follow-up of seven years. Conclusion: Incidence of pulmonary metastasis in GCTB is 4% and of local recurrence is 31%. Intralesional curet- tage/subtotal resection has similar risk of local recurrence (30%) as wide resection (29%) but may increase the risk of pulmonary metastasis. There is no association between metastasis and site of the primary bone lesion. Patients with pulmonary metastasis of GCTB seem to have good prognosis. 146 Blastomycosis in Immunocompromised Patients: A Clinicopathologic Review Christine Rupcich, MD, Vijaya Reddy, MD, Paolo Gattuso, MD; Rush University Medical Center, Chicago, IL Introduction: The majority of invasive fungal infections in immunocompromised patients are due to Aspergillus, Candida, and zygomycetes. However, literature regarding blastomycosis infection in immunocompromised patients is sparse and is mainly limited to single case reports. We conducted a retrospective review of blastomycosis infec- tion encountered in cytologic and surgical specimens, with emphasis on the relationship with immunocompro- mised patients. Methods: Our pathology fles from 1994 to January 2017 were searched for blastomycosis infection. The clinical and pathologic data were reviewed in detail. All cases were diagnosed based on morphologic characteristics and sup- ported by ancillary studies, such as PAS and GMS stains. Microbiology cultures, when available, were recorded. The patients’ medical histories were reviewed to deter- mine immune status. Patients considered immunocom- promised had one or more of the following conditions: renal transplant, myelodysplastic syndrome/lymphoma/ leukemia, other malignancy, diabetes mellitus, viral hep- atitis, human immunodefciency virus, sarcoidosis, end stage renal disease, or rheumatoid arthritis. Results: A total of 39 cases from 38 patients with availa- ble clinical history were recorded. There were 25 male and 13 female patients. The mean age was 51.2 years (range 13–76). Six cases were cytologic material: fve bronchial lavages and one brushing. Thirty-two cases were surgical pathology cases: 11 lung, eight soft tissue, fve bone, four skin, two lymph node, one brain, and one thoracic mass. Of 38 patients, 28 (74%) were immunocompromised. Seven patients had disseminated infections. Thirty-four cases had at least one concurrent culture, nine of which were negative. Conclusion: Almost two-thirds of patients with blasto- mycosis were immunocompromised (28/38, 74%), includ- ing six of seven with disseminated infections. The most common location for blastomycosis infection was lung, followed by soft tissue and bone. Cultures were positive in 74% of patients with a pathology diagnosis consistent with blastomycosis. These results confrm that immuno- compromised patients are at a relatively higher risk for blastomycosis infection. Downloaded from https://academic.oup.com/ajcp/article/149/suppl_1/S62/4801437 by guest on 11 May 2021