Mediastinal Seminoma with an Elevated Level of Serum Angiotensin-converting Enzyme

Testicular seminoma with a progressing pulmonary nodule and mediastinal lymphadenopathy without retroperitoneal metastasis

INTRODUCTION

Testicular germ cell cancer has a relatively good prognosis even if visceral and/or lymph node metastases are present thanks to chemotherapy. Yet chemotherapy can lead to various adverse events. Therefore, it is crucial to distinguish whether a suspected metastatic disease is metastasis or not.

CASE PRESENTATION

A 33-year-old male visited our hospital to receive subsequent therapy for suspected recurrent seminoma with a progressing pulmonary nodule and mediastinal lymphadenopathy after orchiectomy. The pathological diagnosis of needle aspiration and resected specimen of the several lesions was consistent with epithelioid cell granuloma without caseous necrosis. Based on these findings, the lung and mediastinal lymph node lesions were diagnosed as sarcoidosis.

CONCLUSION

In cases where the simultaneous occurrence of other benign or malignant diseases is suspected, pathological confirmation is necessary for appropriate decision-making.

Granulomatous reaction of primary mediastinal seminoma leading to diagnostic delay: a case report

Primary mediastinal seminoma (PMS) is a rare tumor. PMS can be morphologically related to secondary changes in the form of thymic remnants, cystic degeneration, epithelioid granulomas, fibrotic change, and syncytiotrophoblast-like cells. Ours was an interesting case where a 26-year-old male presented with an incidentally-found anterior mediastinal mass. Even though he had no pulmonary symptoms, the transthoracic co-axial needle biopsy of the mass suggested tuberculosis (TB). However, on follow-up computed tomography (CT) and magnetic resonance image (MRI) in 2 months, the mass slightly increased in size, and a small part of low density or signal intensity appeared, despite the regular anti-TB treatment regimen. Surgical resection was performed, and the resected specimens revealed scattered and irregular-shaped seminoma cells with an intervening chronic granulomatous reaction. The aim of this article is to report a case of PMS in a young male patient who had a granulomatous reaction that mimicked a neoplastic population of cells leading to an erroneous diagnosis of the small biopsy. Therefore, awareness of the secondary changes that can mimic a primary lesion can help with an early correction of this misdiagnosis.