Successful Treatment for Hepatoblastoma in Trisomy 18: A Case Report.

Children with trisomy 18 tend to develop hepatoblastoma. Since the introduction of appropriate management for organ malfunction, individuals with trisomy 18 have come to have a longer life expectancy. However, the predisposition to hepatoblastoma becomes a significant issue for the quality of a case. Here, we present a rare multifocal hepatoblastoma involving predominantly Couinaud segments 5 and 7 in a 10-month-old boy with trisomy 18. Though the first-line cisplatin monotherapy resulted in unsatisfactory tumor shrinkage, the second-line neoadjuvant chemotherapy administrating irinotecan and vincristine gave rise to significant tumor reduction in volume, leading to the completion of partial resection of the liver without the microscopic residual disease. The patient has been free from recurrence for 44 months. Because anatomical right hepatectomy can cause circulatory instability, including acute onset of pulmonary hypertension in trisomy 18 patients, physicians should balance treatment benefits and potential adverse effects. Our successful experience utilizing a combination of efficacious and less cardiotoxic neoadjuvant chemotherapy followed by the partial hepatectomy encourages physicians to treat a patient with trisomy 18 and tackle hepatoblastoma with a genetic background.

Distinct clonal evolution in a case with anaplastic embryonal rhabdomyosarcoma.

BACKGROUND: Clonal evolution of malignancy is a complex process related to intratumoral heterogeneity, as recent studies have also demonstrated in rhabdomyosarcoma. The purpose of this study is to present a distinct clonal feature of a case with anaplastic embryonal type rhabdomyosarcoma (ERMS) using molecular analysis. METHODS: A five-year-old girl developed a metastatic pelvic tumor. We cultured neoplastic cells isolated from the biopsy sample. Next, to characterize the current case, we analyzed the biopsy sample, autopsy sample, and established cell line using combined modalities, including histopathological, cytogenetic, and molecular assay. We also undertook the backtrack mutation-specific polymerase chain reaction to reveal clonal composition. RESULTS: The histology of the biopsy sample was consistent with ERMS with focal anaplasia. We established a permanently growing cell line, ICH-ERMS-1, from the biopsy sample. On molecular analysis, the biopsied tissue revealed a missense mutation at codon 245 of TP53. In contrast, the autopsy tumor tissue and the cell line established from the biopsied tissue showed a missense mutation at codon 248. A backtrack study using mutation-specific polymerase chain reaction detected a TP53 codon 248 mutation in the original biopsy sample. All the specimens examined had a missense mutation at PTPN11 codon 69. CONCLUSIONS: This study highlights intratumoral heterogeneity and distinct clonal change related to the functional context in our anaplastic ERMS case, supporting the concept of intratumoral heterogeneity and clonal evolution. It requires further case collection to reveal whether p14ARF-p53-MDM2 tumor suppressor pathway alteration, considered a late event in ERMS tumorigenesis, is responsible for anaplasia in ERMS.

A case of microscopic, multiple sclerosing pneumocytoma.

Sclerosing pneumocytoma is a rare tumor of the lung, commonly affecting middle-aged women, and is mostly isolated. Although this tumor is thought to be derived from primitive respiratory epithelial cells, the characteristics of the precursor cells are still unknown. A 19-year-old woman presented with multiple nodules in the right lung. Partial resection of the right middle lobe was performed, and seven sclerosing pneumocytomas, including four that were microscopic, were detected. The latter showed a simple papillary pattern, and three of them consisted of only round cell-like cells (single population). Interestingly, these round cell-like cells were positive for both p63 and TTF-1, but totally negative for SP-A. On the other hand, the tumor cells of the other four sclerosing pneumocytomas showing a papillary pattern with a dual population, were diffusely positive for TTF-1 and focally positive for SP-A (only in surface cells), but negative or very focally positive for p63. It has been reported that p63-positive stem cell-like cells are present in the distal airway and have potential to differentiate into type II pneumocytes. The immunohistochemical features of these multiple microscopic lesions suggest that the p63-TTF-1 double-positive cells are candidate precursor cells of sclerosing pneumocytoma.