UNASSIGNED: The absence of prostate cancer on final surgical pathology after biopsy-proven prostate cancer is a rare finding.
UNASSIGNED: Case of pT0 prostate cancer following Gleason Grade Group 4 in 1 out of 12 cores from a transrectal ultrasound-guided biopsy in a man who underwent both magnetic resonance imaging and 18F-PSMA-1007 Positron Emission Tomography prior to radical prostatectomy.
UNASSIGNED: pT0 prostate cancer is rare. The use of novel imaging modalities may help in the workup of prostate cancer.

Primary retroperitoneal carcinomas are very rare tumors. Their pathogenesis remains unknown but may be associated with that of ovarian carcinomas, considering the similarity in morphology and gender preference. Although metaplasia of coelomic epithelium is the most widely accepted theory, the pathogenesis of retroperitoneal carcinomas may differ by histologic subtype, like ovarian carcinomas. Mucinous carcinoma, which develops in both women and men, may originate in both primordial germ cells and Walthard cell nests that may be derived from the fallopian tube. Serous carcinomas may be associated with endosalpingiosis, the presence of fallopian tube-like epithelium outside the fallopian tube, and a remnant Müllerian tract. Endometrioid and clear cell carcinomas appear to be associated with extraovarian endometriosis. Additionally, both carcinomas in the retroperitoneal lymph nodes may be metastatic diseases from endometrial and/or renal cell cancer that regress spontaneously (carcinoma of unknown primary). Retroperitoneal carcinomas are difficult to diagnose, as they have no characteristic symptoms and signs. Surgery is the cornerstone of treatment, but the necessity of chemotherapy may depend on histological subtype. Further studies are necessary, in particular studies on endosalpingiosis, as endosalpingiosis is a poorly understood condition, although it is associated with the development of both serous and mucinous carcinomas.

(1) Background: Following radical prostatectomy (RP), the absence of a demonstrable tumor on the specimen of a previously histologically proven malignancy is known as the pT0 stage. The aim of our present study is to perform a narrative review of current literature in order to determine the frequency and oncological outcomes in patients with pT0 disease. (2) Methods: A narrative review of all available literature was performed. (3) Results: The incidence of pT0 ranges between 0.07% and 1.3%. Predictors of the pT0 stage are only a single biopsy core with low-grade cancer, a cancer length not exceeding 2 mm and a high prostate volume. Biochemical recurrence ranges between 0 and 11%. (4) Conclusions: The absence of malignancy in the RP specimen despite a previous positive biopsy is a rare and unpredictable finding. Although the prognosis is considered to be excellent in most of the cases, a continued close follow-up is warranted.

The incidence of pT0 prostate cancer (CaP) at radical prostatectomy (RP) is extremely rare. We performed the first population-based analysis of pT0 CaP at RP.
Within the Surveillance, Epidemiology, and End Results database (2004-2015), we tested for clinical and pathological characteristics according to pT0 vs. non-pT0 CaP and included a multivariable logistic regression model.
pT0 was identified in 358 (0.2%) out of 160,532 clinically localized RP patients. The majority of pT0 patients presented with initial prostate-specific antigen (PSA) <10 ng/ml (82.4%), harboured biopsy Gleason score (GS) 6 (69.8%) and cT1 disease (78.1%). Nonetheless, pT0 was identified in 13 (3.6%) patients with PSA ≥20 ng/ml, in 69 (19.3%) patients with biopsy GS ≥7 and in 78 (21.8%) patients with ≥cT2 disease. In a subset of patients with available number of biopsy cores, pT0 was identified in 34 (33.3%) patients with ≥2 positive biopsy cores. Age, race, marital status, hospital region, population density, PSA, as well as number of biopsy cores did not discriminate between pT0 and non-pT0 cases. Analyses according to annual rates (2004-2015) of pT0 did not vary between the years (0.2%-1.6%, estimated annual percent change: -1.6%, P = 0.3). Neither did the rates vary according to geographic region.
pT0 at RP is very rare. Even though, most pT0 patients have low PSA, low clinical stage, low biopsy GS, and only one positive biopsy core, those with more aggressive characteristics can still harbour pT0 at RP.

BACKGROUND: The phenomenon of vanishing carcinomas, first described in context of prostatic carcinomas, has been documented in endometrial carcinomas as well.
METHODS: The archives of the department were searched for case files of endometrial carcinoma diagnosed on endometrial curetting/biopsy but which did not reveal any cancer on the subsequent hysterectomy specimen. Clinical and pathological correlation was established.
RESULTS: A total of 5 cases were retrieved with biopsy-diagnosed endometrial carcinomas, 4 endometrioid and 1 serous type, which on subsequent hysterectomies did not reveal any tumor. These 5 cases represented 1.56% of total hysterectomies in our series. All were Stage Ia tumors, which on follow-up (mean = 18.2 months) did not show any local reoccurrence. Adjuvant therapy was instituted in 1 case in the form of pelvic irradiation in view of the serous histology. In all cases, the primary diagnosis was reconfirmed and any remote possibility of incorrect patient identification, laboratory errors, and institution of hormonal therapy were adequately ruled out along with an extensive endometrial sampling in hysterectomy.
CONCLUSIONS: The recognition of \"vanishing endometrial carcinoma\" as a distinct entity is of utmost importance to avoid mislabeling them as medical errors.

Background/aim: The vanishing cancer phenomenon was first reported in radical prostatectomy specimens in the absence of neo-adjuvant treatment. Reported cases are mostly well-differentiated and low-volume tumors. A similar entity was described for hysterectomy specimens of patients with biopsy proven endometrial cancer (EC). In this study, we discuss the probable reasons for vanishing EC and long-term follow-up results of EC patients without residual tumors in hysterectomy specimens. Materials and methods: This study was carried at two institutions in Ankara, Turkey, in a retrospective design. The computerized databases of both institutions were searched for endometrioid type EC patients whose final pathological specimens failed to show any residual tumor. Results: We evaluated 38 endometrial biopsy confirmed EC patients with no residual tumor detected in the hysterectomy specimens among a total of 224 women (17%) with the disease confined to the endometrium. During the follow-up period, no recurrences were noted among the patients. Conclusion: It can be suggested that premenopausal women with FIGO grade 1 endometrioid type EC with MRI proven \"absent myometrial invasion\" would have a significant probability of having no residual tumor after endometrial biopsy without any further medical treatment.

BACKGROUND: Fine-needle aspiration (FNA)-induced secondary changes were described in various organs. Complete replacement of tumor by necrosis causes diagnostic and management problems.
METHODS: Seven cases of totally or partially vanished thyroid lesions were identified from the archive of Department of Pathology, Fimlab Laboratories within 5 year period. Histopathological slides were revised in all cases.
RESULTS: Total thyroidectomy or lobectomy samples were from 4 females and 3 males patients aged 37-83 years (mean 67.1 years). Imaging data were available in 6 cases. Cytology slides and data were available only in 3 cases: two revealed follicular neoplasm and one was insufficient according to Bethesda system. In 5 cases, final histopathology revealed total necrosis of the lesion with only one case with available cytological diagnosis of oncocytic follicular neoplasm. In remaining 2 cases, replacement by necrosis was partial. Of note, in three cases, oncocytic metaplasia was present.
CONCLUSIONS: Total histopathological blocking with thorough check of capsular areas is recommended in necrotic tumors. Vanishing thyroid lesion phenomenon is rare, but in cases of disappearance of tumor, preoperative cytology diagnosis is the only clue for the patient management. Diagn. Cytopathol. 2016;44:568-573. © 2016 Wiley Periodicals, Inc.