PMC4247932_01
Contrast-enhanced CT scan of the pelvis demonstrates a 6.5 x 5.1 cm mass within the right pelvis (arrows), bordered by the right obturator internus, right seminal vesicles, and bladder diverticulum. The epicenter of the mass is centered at the internal iliac neurovascular bundle.
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CT showed a 7 x 5 cm mass within the right pelvis, bordered by the right obturator internus, right seminal vesicles, and bladder diverticulum (Figures 1(a) and 1(b)).
Hematoxylin and eosin (H&E) stain at 100x, 200x, and 400x power, respectively, demonstrates metastatic squamous cell carcinoma. At 400x power (c), intracellular bridges (yellow arrows) and eosinophilic, intracytoplasmic keratin (black arrow) are seen, indicating squamous differentiation.
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CT guided percutaneous biopsy showed a perirectal, invasive, moderately differentiated, keratinizing, squamous cell carcinoma (Figures 2(a), 2(b), and 2(c)).
P63 immunostain shows positive nuclear staining in tumor cells ((a), (b)), as well as cytoplasmic staining (b), supporting the diagnosis of squamous cell carcinoma.
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Immunostain was strongly positive for pankeratin and positive for CK5, CK6, and P16 (Figures 3(a) and 3(b)).
Contrast-enhanced CT scan of the pelvis demonstrates a 3.4 x 1.7 cm pelvic lesion (arrows) with no substantial soft-tissue component. The lesion is linear and elongated and appears to be comprised mainly of necrotic tissue, consistent with postradiation changes.
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Follow-up CT chest, abdomen, and pelvis at 12 months after diagnosis (8 months after beginning treatment) showed a continued interval decrease in size of the pelvic lesion to 3.4 x 1.7 cm (Figures 4(a) and 4(b)).