Do Histologically Aggressive Subtypes of Papillary Thyroid Microcarcinoma have Worse Clinical Outcome than Non-Aggressive Papillary Thyroid Microcarcinoma Subtypes? A Multicenter Cohort Study.

Histologically aggressive micropapillary thyroid carcinomas (PTMC) subtypes are thought to be associated with an aggressive clinical course. However, evidence for unfavorable clinical outcomes in patients with aggressive PTMC subtypes is not clear. In this study, we intended to determine the difference in clinical outcomes between patients with aggressive and non-aggressive PTMC subtypes. In this multicenter cohort study, the computer-recorded clinical and histopathological data of patients who underwent thyroid surgery between January 2000 - January 2021 in 9 referral centers and were diagnosed as PTMC were analyzed. A total of 1585 patients [female 1340 (84.5%), male 245 (15.5%), mean age 47.9±11.63 years), with a mean follow-up time of 66.55±37.16 months], were included in the study. Ninety-eight cases were diagnosed as aggressive and 1487 as non-aggressive subtypes. Persistent/recurrent disease was observed in 33 (33.7% )and 41 (2.8%) patients with aggressive and non-aggressive subtypes (p<0.001). Diseases-free survival rates were markedly lower in patients with aggressive than in those with non-aggressive PTMC subtypes (66.3 vs. 94.8%, log-rank p<0.001). Moreover, in multivariate analysis, aggressive histology was an independent predictor of persistent/recurrent disease, after controlling for other contributing factors (HR 5.78, 95% CI 3.32-10, p<0.001). Patients with aggressive PTMC subtypes had higher rates of incomplete biochemical and structural response than patients with non-aggressive subtypes as well (p<0.001). Aggressive PTMC subtypes share many characteristics with histologically identical tumors>1 cm in size. Therefore, the histopathological subtype of PTMC should be taken into consideration to tailor a personalized management plan.

Histiocytic Sarcoma with Invasive Urothelial Carcinoma of Urinary Bladder.

We report a rare case of histiocytic sarcoma in association with invasive urothelial carcinoma involving the urinary bladder. A 67-year male patient, who presented with a complaint of macroscopic hematuria, was found to have a mass on urinary system ultrasonography. Abdominal magnetic resonance imaging was performed to evaluate the mass, which showed a 52×24 mm mass on the posterior wall of the bladder. The cystoscopic examination revealed two suspicious areas in close proximity to one another with solid-papillary character. The tissue samples were collected by means of transurethral resection. The evaluation of these samples revealed two distinct neoplastic patterns. The areas of invasive urothelial carcinoma infiltrating lamina propria were noted on the surface in addition to diffuse sheets of large cells with hyperchromatic nuclei and ample clear cytoplasm, with a patternless pattern among small lymphocytes in myxoid background in the lamina propria. The positive reactions were observed in these areas with CD45, fascin, and CD68, a histiocytic marker. The histopathological diagnosis was histiocytic sarcoma in combination with invasive urothelial carcinoma. Histiocytic sarcoma may mimic several other malignant lesions, and only immunohistochemistry can identify this tumour to allow correct treatment. We present this rare case to emphasise that this phenomenon should be considered in unusual tumors and sites. Key Words: Urinary bladder, Histiocytic sarcoma, Invasive urothelial carcinoma.

The shrinkage effect of formalin on renal cell carcinoma: Does it change the stages.

Objective: To determine the shrinkage effect of formalin on renal cell carcinoma. METHODS: The retrospective study was conducted from October to November 2020 at Tekirdag Namik Kemal University, Turkey, and comprised all radical and partial nephrectomy cases performed by a single surgeon in a single clinic between January 2014 and August 2020. Pre-operative images and post-operative pathology were reviewed by the same clinician. Pre-operative longest tumour diameter of radiological images and pathological specimens measured after formalin fixation shrinkage were compared, and the effect of the difference between the two measurements on the circumference of the tumour was examined. The formalin-related shrinkage rates of renal tumours according to the tumour size and the tumour types were also analysed. Data was analysed using SPSS 20. RESULTS: Of the 101 cases, 58(57.4%) were of radical and 43(42.6%) of partial nephrectomy. Also, there were 77(76.2%) renal cell carcinoma cases, 22(21.8%) benign renal tumours and 2(1.9%) had other malignant tumours. There were 59(58.4%) males and 42(41.6%) females with an overall mean age of 58.1±12,2 years (range: 30-82 years). The mean radiological size of the renal tumours was 55.3±30.4 mm and it was 52.9±31.6 mm at pathological examination (p>0.05). Conclusion: Formalin fixation of tissues post-surgery caused a difference between the radiological and pathological dimensions. Though the difference was no significant, under-staging due to the shrinkage post-surgery should be considered.

Intraparenchymal Leiomyoma of the Breast: A Rare Location for an Infrequent Tumor.

Intraparenchymal leiomyoma of the breast are among benign non-epithelial tumors with the lowest incidence. Although it displays a benign histology, it may be confused with malignant lesions and create diagnostic confusion. In this paper, we report a 44-year-old woman with a painless mass with a diameter of 1.5 cm in the upper medial quadrant of her right breast. The lesion was removed surgically. The lesion's histologic examination and immunohistochemical analysis revealed a smooth muscle tumor of the breast. The patient was initially diagnosed with fibroadenoma and was followed in terms of the epicenter for six months before she underwent surgery. Her mammography and histopathology results are discussed in this report.