{'fraction_non_alphanumeric': 0.03301622831561276, 'fraction_numerical': 0.006715165081141578, 'mean_word_length': 5.501818181818182, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Prostatic adenocarcinoma with Paneth cell‐like change

We report a case of prostatic adenocarcinoma suggestive of a close relationship between prostatic adenocarcinoma with Paneth cell-like change and high-grade PIN with Paneth celllike change. A 75-year-old Japanese man was found to have prostatic cancer and prostatectomy was performed. Microscopically, the tumor cytoplasm had large eosinophilic granules in 5% of all the neoplastic cells, resulting in Paneth celllike change. Rosette structures were seen focally (Fig. 1). Additionally, high-grade prostatic intraepithelial neoplasia (PIN) was observed not only in the area adjacent to the prostatic adenocarcinoma with Paneth cell-like change (Fig. 2), but also in the area apart from the prostatic adenocarcinoma. Immunohistochemically, synaptophysin showed focally a positive reaction in the cytoplasm of neoplastic cells of the adenocarcinoma with Paneth cell-like change and the adjacent high-grade PIN with Paneth cell-like change. Paneth cell-like change is rarely observed in both benign and malignant prostatic diseases (1–5). Among benign lesions, this change is observed in normal glands, hyperplastic glands or prostatic glands after three-dimensional conformal external beam radiation therapy (1, 2, 5). Whether the term ‘‘Paneth cell-like change’’ is appropriate is debatable. In actual fact, eosinophilic granules in Paneth cell-like change are not true Paneth cell granules either immunohistochemically or ultrastructurally (3, 4). Furthermore, the nature of this change in benign lesions is essentially different from that seen in malignant lesions. Paneth cell-like change in benign lesions shows positive reaction for PAS stain and diastase pretreatment PAS stain, but does not show neuroendocrine differentiation