Petrous apex metastasis revealing prostate cancer: a rare case report and review of literature.

INTRODUCTION AND

IMPORTANCE

Temporal bone malignancies are rare, representing only 0.2% of head and neck malignancies, with an annual incidence of 1 to 6 cases per million. Metastatic involvement of the petrous apex is particularly uncommon, with prostate cancer accounting for approximately 8.6% of temporal bone metastases. We report an extremely rare case of metastatic prostate cancer presenting with otologic symptoms and a destructive petrous apex lesion in a patient with no prior oncological history.

CASE PRESENTATION: A 73-year-old male presented with right-sided tinnitus, vertigo, and headaches. Audiological workup was unremarkable aside from bilateral presbycusis. CT and magnetic resonance imaging (MRI) imaging revealed a lytic lesion of the right petrous apex extending to the occipital basion and compressing the jugular bulb. Diagnostic mastoidectomy with biopsy demonstrated a poorly differentiated invasive adenocarcinoma with immunohistochemical profile confirming prostatic origin. Prostate-specific antigen was above 100 ng/mL. Positron emission tomography-computed tomography (PET-CT) revealed hypermetabolic prostatic disease with widespread osseous and lymph node metastases. The patient was subsequently initiated on androgen deprivation therapy (ADT) + radiotherapy.

DISCUSSION: Temporal bone metastases from prostate cancer are exceedingly rare, with fewer than 30 cases reported in the literature. Diagnosis is frequently delayed due to nonspecific otologic presentation and the osteolytic pattern, which is atypical for prostatic metastases. A multimodal approach combining high-resolution computed tomography, MRI, prostate-specific membrane antigen PET-CT and histopathological analysis with immunohistochemistry is essential for accurate diagnosis. Treatment remains primarily palliative, incorporating androgen deprivation therapy, radiotherapy, and emerging systemic agents.

CONCLUSION

A malignant metastatic etiology must always be considered, especially prostate cancer in male patients, even in the absence of a known oncological history. Early recognition through thorough radiological and pathological workup is essential to optimize management and quality of life.