Case report
Year : 2026 Month : April Volume : 15 Issue : 2 Page : PC04 - PC06 Full Version

Metastatic Prostatic Acinar Adenocarcinoma Presenting as a Penile Malignant Tumour: A Case Report
Gwendolyn Fernandes, Kaustubh Vilasrao Kharche, Amey Rojekar
1. Professor (Addl.), Department of Pathology, G.S. Medical College and K.E.M Hospital, Mumbai, Maharashtra, India. 2. Fellow in Uropathology, Department of Pathology, G.S. Medical College and K.E.M Hospital, Mumbai, Maharashtra, India. 3. Professor (Addl.), Department of Pathology, G.S. Medical College and K.E.M Hospital, Mumbai, Maharashtra, India.
 
Correspondence Address :
Dr. Gwendolyn Fernandes
B2-801, Mahindra Vivante, Near Western Express Metro Station, Andheri (E),
Mumbai, Maharashtra, India.
E-mail: drgwenfern@yahoo.co.in
 
ABSTRACT
: Penile metastasis from occult prostatic acinar adenocarcinoma is extremely rare and has been described in only a few case reports in the literature. The incidence of metastasis from known prostatic adenocarcinoma to the penis is less than 0.3%. The present case report involves a 72-year-old man presented with a hard penile mass measuring 2×1.5×1 cm for three months. He also reported lower urinary tract symptoms, two or three episodes of haematuria, anorexia, weight loss, and low back pain. A wedge biopsy of the penile mass was initially reported as adenosquamous carcinoma. Contrast-Enhanced Computed Tomography (CECT) revealed a heterogeneously enhancing, irregular distal penile lesion measuring 2×1.5×1 cm. Mild prostatomegaly measuring 36 cc was noted. Serum Prostate-Specific Antigen (PSA) level was 34 ng/mL. Three weeks later, the patient developed acute urinary retention, and the PSA level increased to 54 ng/mL. Total Penectomy and Transrectal Ultrasound (TRUS) guided biopsy of the prostate were performed. Histopathology revealed prostatic adenocarcinoma with a Gleason score of 8 (4+4), corresponding to Grade Group 4, while the penectomy specimen showed metastatic prostatic adenocarcinoma. Immunohistochemistry (IHC) demonstrated strong positivity for NK3 homeobox 1 (NKX3.1) and PSA, confirming the prostatic origin of the penile lesion. Unlike the present case, most reported patients with penile metastasis from prostatic adenocarcinoma have a known history of prostate cancer diagnosed years before the appearance of penile lesions. Presentation of occult prostatic carcinoma as a primary penile malignant tumour is highly unusual. Thorough clinical evaluation of the prostate in patients with genitourinary malignancies is therefore essential, particularly in the presence of elevated PSA levels.
Keywords : NKX 3.1, Occult malignancy, Penile mass, Prostatic carcinoma, Prostate-specific antigen
DOI and Others : DOI: 10.7860/NJLM/2026/82590.2967 Date of Submission: Aug 07, 2025 Date of Peer Review: Sep 23, 2025 Date of Acceptance: Jan 03, 2026 Date of Publishing: Apr 01, 2026 AUTHOR DECLARATION: • Financial or Other Competing Interests: None • Was informed consent obtained from the subjects involved in the study? Yes • For any images presented appropriate consent has been obtained from the subjects. Yes PLAGIARISM CHECKING METHODS: • Plagiarism X-checker: Sep 02, 2025 • Manual Googling: Dec 27, 2025 • iThenticate Software: Jan 02, 2026 (4%) ETYMOLOGY: Author Origin EMENDATIONS: 6
 
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