Unexpected Malignant Diagnosis in Colonic Biopsies: Malignant Transformation of Ovarian Mature Teratomas—Two Case Reports and Review of the Literature

Figure 1

(a) Abdomen and pelvis CT showing a heterogenous mass with cystic and solid component. (b) Colon biopsy (H&E, 40x) showing a dysplastic squamous cell epithelium with keratin material, suspicious for squamous cell carcinoma. (c) Gross picture showing a cystic teratoma with sebaceous material and hair (right), the colon (left), and a firm white tan mass in between. (d) Squamous cell carcinoma (inferior left) invading into the colonic wall up to the submucosa (H&E, 20x). (e) P63 immunostain highlighting the tumor (20x). (f) Negative p16 immunostain (20x). (g) In situ squamous cell carcinoma (H&E 20x). (h) In situ squamous cell carcinoma with invasive component (H&E, 10x).

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