<s>[INST] context: .Seminoma Testis * Stas in the mediastinum of testis. * Grossly it is lobulated, fleshy, homogenous, creamy or pinkish in colour and it compresses adjacent testicular tissue. * Histologically, malignant cells resemble spermatocytes which are cells containing clear cytoplasm with large nucleus, and are arranged in sheets with fibrous stroma in between which is in turn infiltrated by lymphocytes. * It spreads through testicular lymphatics into the paraaoic lymph nodes and then to left supra-clavicular lymph node. Through blood, it spreads to lungs, bone, brain, liver. Histological Classification * Germ cell tumour. - Seminomatous - classic; spermatocytic; anaplastic. - Nonseminomatous type - embryonal carcinoma; teratomas; choriocarcinoma; yolk sac tumour (endodermal sinus tumour contains Schiller Duval bodies). * Sex cord stromal tumours - Leydig cell tumour; Seoli cell tumour; granulosa cell tumour. * Combined germ cell and gonadal stromal tumour - Gonadoblastoma. * Adnexal and paratesticular tumours - mesothelioma; sarcomas. * Others - carcinoids; lymphomas. * Secondaries. ref:SRB&;s manual of surgery,ed 3,pg no 1032 [/INST] question: Most common testicular tumor in prepubeal adults is | options: A: Yolk sac tumor B: Embryonal cell Ca C: Seminoma D: Teratoma | answer: A </s>