Growing teratoma syndrome presented as a left forearm mass: A case report. Ioannis Litos 1* , Eleni Maragkouli 1 , Vassilis Papadopoulos 1 , Konstantinos Tsapakidis 1 , Konstantina Papacharalambous 2 , Ioannis Samaras 1 , Eleni Sogka 1 , Athina Isaakidou 1 , Alexandra Markou 1 , George Papatsimpas 1 1 Department of Medical Oncology, University of Thessaly, Larissa, Greece 2 Department of Pathology, Faculty of Medicine, University of Thessaly, Larissa, Greece Abstract Growing teratoma syndrome (GTS) is a rare disease occurring in patients with non-seminomatous germ cell tumors (NSGCT), which is characterized by enlarging masses in the presence of normal tumor markers either during or after completion of chemotherapy. The disease is chemo-resistant and radio-resistant and complete surgical removal offers the best chance of long-term survival. GTS was first described by Logothetis et al. in 1982, who designated criteria to diagnose this rare entity [1]. The fact that GTS is not common leads to delays in diagnosis and surgical intervention. This case report refers to a testicular growing teratoma with its first clinical manifestation being a gigantic forearm mass. Keywords: Teratoma syndrome, Chemotherapy, Tumor markers. Accepted on July 24, 2018 Case Presentation A 34-year-old man, with a history of cryptorchidism, presented with a progressively enlarging ulcerated lesion on the left forearm (Figure 1) and abdominal pain. Initially, a biopsy was performed by an Orthopedist. While waiting for the biopsy results, the abdominal pain was intensified and the patient was admitted to the hospital. Clinical examination revealed a palpable left testicular mass and palpable liver in addition to the left forearm lesion. The main laboratory findings included raised AFP (538 ng/ml), β-HCG (87 mIU/ml), LDH (1166 IU/L). Thoracic and abdominal computed tomographies showed a giant cystic tumor on the left of the abdomen and lung as well as liver metastases. Brain MRI was negative for abnormal findings. Figure 1. The mass of the left arm. Due to clinical deterioration with aggravation of the abdominal pain, the patient was submitted to an urgent laparotomy which proved a small bowel rupture. A bowel resection was carried out concurrently with removal of the cystic mass and hepatectomy, albeit suboptimally. Consequently, a left inguinal orchiectomy was performed. The histopathologic examination of the three bioptical materials (forearm, cystic abdominal mass, testis) highlighted a mixed germ cell tumor with elements of an embryonal carcinoma (50%) and mature teratoma (35%) (Figure 2-4). Figure 2. Embryonal carcinom-Pseudoglandular pattern. High grade features of large, epithelioid, anaplastic cells with prominent nucleoli, indistinct cell borders with nuclear overlapping, pleomorphism, frequent mitoses. Eosinophilic coagulative necrosis with resemblance to comedocarcinoma. Case Report http://www.alliedacademies.org/molecular-oncology-research/ J Mol Oncol Res. 2018 Volume 2 Issue 3 45