Miriam Velazquez, Wafaa Elatre
Clinical History
The patient is a 47 year old male with no significant past medical history who presents with abdominal pain, chest pain, and dyspnea. Imaging showed a 24cm abdominal mass with encasement of the aorta, infrarenal IVC and right ureter invasion, bladder thickening, pulmonary embolisms, lymphadenopathy, and heterogenous attenuation of sacrum and pelvic bones. Prior to admission, the patient stated he had worsening abdominal distension, low back pain, weight loss, fevers, night sweats, and bloody urine for the past couple of months. Fine needle aspiration (FNA) and core needle biopsy of the abdominal mass was insufficient for definitive diagnosis and core needle biopsy of left supraclavicular lymph node was performed.
Cytologic description
Touch preparations of the core needle biopsy of the left supraclavicular lymph node showed discohesive cells with enlarged, irregular nuclei, fine chromatin, prominent nucleoli, and scant to moderate cytoplasm. The background showed lymphocytes and a tigroid background. The H&E of the core needle biopsy showed similar findings; however, the tigroid background is no longer appreciated. An extensive immunhistochemical (IHC) workup was performed and showed the tumor cells were weakly positive for pancytokeratin and CK7, but CK20 negative. PAX8, GATA3, TTF1, synaptophysin, chromogranin A, SOX10, Melan-A, myogenin, MyoD1, CD30, and Glypican-3 were negative. CD45 highlighted background lymphocytes. SALL4, PLAP, OCT3/4 were positive. The cytomorphology, histomorphology, and immunophenotype together are consistent with a germ cell tumor and a diagnosis of seminoma was rendered. Further workup revealed an ill-defined, heterogeneous area in the superior aspect of the right testis and an adjacent 0.7cm isoechoic focus with a hypoechoic rim. Chemotherapy regimen was initiated as the patient was not considered a surgical candidate.
Discussion
Seminoma is a malignant germ cell tumor that derives from cells similar to primordial germ cells/gonocytes found in early embryonic development. Seminomas arise from the testis and are immunophenotypically and morpholocigally identical to germinomas and dysgerminomas that arise from the ovary, mediastinum, and pineal gland. Seminoma is the most common germ cell tumor of the testis and accounts for >50% of testicular germ cell tumors. Seminoma has a predilection for young men (37-41 years old); however, it can also be seen in men > 50 years old. Patients often present with a self-identified mass and vague discomfort in the testis. Less than 3% present with symptoms related to retroperitoneal metastasis such as lower back pain. Metastasis occurs via lymphatics to retroperitoneal lymph nodes, then to mediastinal and cervical lymph nodes.
Cytologically, seminomas appear as discohesive cell groups, flat sheets and individually with round to oval nuclei, fine chromatin, and prominent nucleoli. Cells have moderate cytoplasm that is delicate with vacuoles containing glycogen. The background often has a lymphocytic infiltrate and the characteristic tigroid pattern resulting from fragmented cytoplasm containing glycogen. Seminomas stain positive for SALL4, OCT3/4, PLAP, but are negative for AE1/AE3, CD30, AFP, and EMA.
References
1. BlueBooksOnline. tumourclassification.iarc.who.int. Accessed April 5, 2024. https://tumourclassification.iarc.who.int/chaptercontent/36/119
2. Cibas ES, Ducatman BS. Cytology: Diagnostic Principles and Clinical Correlates. Fifth edition. Elsevier; 2019.