When a mimicker wears strange faces: description of an osteogenic melanoma arising within an ovarian teratoma with focus on its late peritoneal relapse.

Secondary malignancies arising within mature teratomas are a rare event, originating from malignant transformation of the tissues derived from one of the three germ cell layers. Osteogenic melanoma is exceedingly rare histologic variant of malignant melanoma, in which the melanoma is associated to an osteogenic sarcoma component. To the best of our knowledge, first case of osteogenic melanoma arising within mature ovarian teratoma in a 30-year-old woman without evidence of a primary cutaneous or visceral melanoma. The present case showed an unusual morphological and immunohistochemical pattern and was incorrectly diagnosed as undifferentiated carcinoma. After a 15 years follow-up period, the patient presented a peritoneal recurrence histologically constituted by epithelioid cells with prominent osteoid formation and with immunohistochemical expression of melanocytic markers (S100, HMB-45). Heterozygote Mutation V600E/E complex has been detected in the BRAF exon 15 sequence. The case was then interpreted as osteogenic melanoma. The present case contributes to widen the spectrum of neoplasms derived from malignant transformation of ovarian teratomas and provides also new insights about the clinical behavior of osteogenic melanoma when arising outside its usual anatomical location.

Frozen section accurately allows pathological characterization of endometrial cancer in patients with a preoperative ambiguous or inconclusive diagnoses: our experience.

BACKGROUND: The aim of this study was to assess the agreement rate between intraoperative evaluation (IOE) and final diagnosis (FD) in a series of surgically resected endometrial carcinoma (EC), with a preoperative ambiguous or inconclusive diagnosis by endometrial biopsies and imaging. METHODS: A retrospective study was performed selecting patients who underwent surgery with IOE for suspected EC at our institution from 2012 to 2018. A K coefficient was determined with respect to the histotype, tumor grade, myometrial infiltration and cervical involvement. RESULTS: Data analysis has been performed on 202 women. The IOE evaluation was distributed as Endometrioid (n = 180) and Non-Endometrioid (n = 22). The comparison between the frozen section (FS) and the definitive histological subtype showed an overall agreement rate of 93,07% (k = 0.612) and an agreement of 97.2% for Endometrioid vs 59% for Non-Endometrioid tumors. The FIGO system grading was the same in 91,1% of patients, none was upgraded and in 8,9% downgraded. Observed agreements were 89,11% and 95,54% for myometrial and cervical involvement, respectively. CONCLUSIONS: The good agreement between intraoperative grading, myometrial invasion and their histological definition on permanent sections highlights that FS is a good predictor for surgical outcome, in particular in presence of a preoperative ambiguous or inconclusive diagnostic evaluation.

Hemangioma of the umbilical cord with associated amnionic inclusion cyst: two uncommon entities occurring simultaneously.

This corrects the article DOI: 10.32074/1591-951X-26-17.

Hemangioma of the umbilical cord with associated amnionic inclusion cyst: two uncommon entities occurring simultaneously.

Umbilical cord hemangioma is an uncommon benign vascular neoplasm arising from the free segment of the umbilical cord, distinct from placental and fetal insertion, and is thought to originate from endothelial cells of the umbilical vessels. Cystic changes in the umbilical cord rarely occur as a consequence of the damage to the amnionic surface of the cord caused by the presence of the hemangioma. Until now, a total of 8 cases of umbilical cord hemangioma associated with cystic changes in the umbilical cord have been reported in the literature, however, among these cases, only one showed an associated cyst derived from inclusion of the amniotic epithelium, and the remaining seven cases consisted of hemangiomas with associated pseudocyst of the umbilical cord. We herein report a case of umbilical cord hemangioma with an associated amnionic epithelial inclusion cyst. Clinicopathological features and differential diagnostic considerations are also discussed.

Perineurioma of the colon: an uncommon tumor with an unusual location. Report of a case and review of the literature.

Perineurioma is a relatively rare benign peripheral nerve sheath tumor composed of cells resembling to normal perineurium. Although this tumor may arise in the context of a nerve (intraneural perineurioma), extraneural perineurioma does occur, frequently involving the soft tissues of the lower and upper extremities, trunk and head and neck. Rarely it has also been reported in visceral organs, including gastrointestinal tract. We herein describe the clinicopathologic features of a rare case of a perineurioma presenting as a polypoid lesion of the sigmoid colon, emphasizing the pathologic diagnostic clues.