case_images: PMC10601767_01
case_images: a A 48-year-old woman presenting with advanced PUC (18 x 21 x 36 mm) and bilateral inguinal adenopathies on pelvic MR (sagittal and coronal; T2 sequence). b, c 18F-FDG PET/CT demonstrated significant hypermetabolism of those two inguinal adenopathies. The left adenopathy predominated in size with 21 mm of short axis.
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case_images: F1
case_images: Pelvic magnetic resonance (MR) found a 3.6 cm height lesion of distal urethra with corresponding inguinal adenopathies (shown in Fig. 1a). A 18F-fluorodeoxyglucose positron-emission CT revealed hypermetabolism at the level of those adenopathies, with the left inguinal adenopathy measuring 21 mm of short axis (shown in Fig. 1b, c).
case_images: a Urethral biopsy showed infiltrating urothelial carcinoma of distal urethra (hematoxylin and eosin; magnification: x10) formed by urothelial cells displaying cellular and nuclear polymorphism with marked nucleomegaly (hematoxylin and eosin; x20). b The inguinal node biopsy also showed confluents islets of large neoplastic urothelial cells with a focal squamous cell differentiation and desmoplastic stroma (hematoxylin and eosin, magnification: x10). Abundant mitosis with eosinophilic cytoplasm and atypic irregular nucleus were also seen (hematoxylin and eosin, magnification: x20). c Immunophenotypage of urethral biopsy showed diffuse nuclear and cytoplasmic ("cell-bloc") positivity for p16 protein, which is associated to high-risk HPV infection (magnification: x10 and x20). d The positivity of the urethral biopsy for high-risk HPV was confirmed by the in situ hybridization showing punctate nuclear staining within tumoral cells (HPV III Family 16 probe for high-risk HPV [HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 66] [Ventana, Tucson, AZ]; magnification: x30 and x40).
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case_images: F2
case_images: The pathologic evaluation of the urethral biopsies revealed high-grade urothelial carcinoma of the distal urethra (shown in Fig. 2a). The previous lymph node biopsies were reviewed and showed urothelial carcinoma nodal metastasis with focal squamous cell differentiation (shown in Fig. 2b). Immunohistochemistry of urethral biopsy demonstrated a significant "cell-bloc" positivity for p16 protein and high-risk HPV was detected by in situ hybridization (shown in Fig. 2c, d).
case_images: Complete tumoral response on pelvic MR is seen 3 months after the treatment, with no residual tumoral mass or adenopathy.
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case_images: F3
case_images: Pelvic MR and 18FDG-PET-CT performed 3 months after the treatment showed complete therapeutic response (shown in Fig. 3).