Introduction/Objective Although squamous metaplasia of colonic tubulovillous adenoma is a rare phenomenon, colorectal polyps can show focal squamous metaplasia. While the exact cause in unknown, it has been suggested that mechanical irritation, torsion and chronic inflammation may predispose to squamous metaplasia within large colonic polyps. Methods/Case Report We observed this finding in two men and one woman with colorectal polyps who underwent endoscopic mucosal resection in a three-week timeframe. In two cases the polyps were rectal, while in the third case, it was located in the descending colon. Polyp size ranged from 1-5 cm and were semi-pedunculated. Histologically, all three lesions were tubulovillous adenomas with focal high-grade dysplasia and multiple foci of squamous metaplasia characterized by cells with benign-appearing nuclei, eosinophilic cytoplasm, and solid growth pattern. Some metaplastic foci approached the muscularis mucosae, mimicking adenocarcinoma at low power magnification. Interestingly, these metaplastic foci were reactive against p16 immunohistochemical stain. Results (if a Case Study enter NA) NA Conclusion We present these three cases to add to the few previously reported. Pathologists should be aware of this finding to avoid the overdiagnosis of invasive carcinoma in the setting of nested and pseudo invasive squamous morules, especially in polyps with high grade dysplasia. In addition, squamous metaplasia could be a precursor lesion for colorectal squamous cell carcinoma.

Background: Extramammary Paget's disease (EMPD) is a rare neoplasm that commonly affects post-menopausal women. It usually presents in the anogenital area where apocrine sweat glands are abundant, most commonly in the vulva. The disease is characterised by slow growth and high local recurrence rates. Clinically, EMPD presents as well-demarcated erythematous lesions or plaques that may be ulcerated.Microscopically, it shows a group of atypical cells with abundant clear cytoplasm and nuclear pleomorphism. Methods:We present the case of a 58-year-old female with a history of poorly differentiated squamous cell carcinoma of the cervix, status post-radical-hysterectomy with bilateral salpingo-oophorectomy, and chemoradiation in 2016. The patient also had a long-standing history of vulvar pain, skin changes on her left labia, and itching.Results: Punch biopsies of the vulva revealed acanthosis and acantholysis of the epidermis with an intraepidermal scattering of single, or clusters of, large cells with round/oval nuclei and abundant clear cytoplasm. The cells were positive for p16, CK19, CK7, and PAX8, supporting the diagnosis of EMPD without evidence of dysplasia. The concurrent Papanicolaou smear showed a hypercellular specimen composed of hyperchromatic tissue fragments with high nuclear-to-cytoplasmic ratios and apoptotic bodies. The presence of intracytoplasmic mucin and the tridimensionality of the fragments supported the diagnosis of adenocarcinoma. Conclusions:This study compares the histological and cytomorphological features of EMPD with high-grade squamous intraepithelial lesions, since the pathogenesis, precursor lesions, etiological associations, staging, clinical treatment, and prognosis differ substantially and may have a significant clinical impact on the patient's treatment.

Introduction/Objective Extramammary Paget disease (EMPD) is a rare neoplasm commonly affects postmenopausal women. It usually presents in the anogenital area where apocrine sweat glands are abundant, most commonly in the vulva. The disease is characterized by slow grow and high local recurrence rates. Clinically, EMPD present as well demarcated erythematous lesion or plaques that may ulcerated. Microscopically, it shows a group of atypical cells with abundant clear cytoplasm and nuclear pleomorphism. Methods/Case Report Here in we present a 58-year-old female with history of vulvar intraepithelial neoplasia III (VIN III) status post wide local excision, and poorly differentiated squamous cell carcinoma status post radical hysterectomy and bilateral salpingo-oopherectomy and chemoradiation who presented for perineal pain, itching and discomfort. She also noticed skin changes on her left labia without bleeding or discharge. Punch biopsies of the vulva and periurethral areas revealed acanthosis of the epidermis with intraepidermal scattering of single or clusters of large cells with round/ovoid nuclei and abundant clear cytoplasm. The cells are positive for p16, CK19, CK7, PAX8 supporting the diagnosis of EMPD without evidence of dysplasia. The concurrent PAP smear shows hypercellular specimen composed of hyperchromatic fragments of tissue with high nuclear-to-cytoplasmic rations, and apoptotic bodies. The presence of intracytoplasmic mucin and the tridimensionality of the fragments supported the diagnosis of adenocarcinoma. The HPV testing was positive for HPV-16. Results (if a Case Study enter NA) N/A Conclusion This study compares the histological and cytomorphological features of EMPD with high-grade squamous intraepithelial lesion (HSIL), since the molecular pathways, precursor lesions, etiologic associations, staging, clinical treatment, and prognosis differ substantially and may have a significant clinical impact for the patient’s treatment.