Background: Clinical trials have demonstrated that the 21-gene assay (Oncotype DX) can predict the benefits of adjuvant chemotherapy in patients with hormone receptor-positive (HR+) and human epidermal growth factor 2-negative (HER2−) breast cancer. This study investigated the real-world utilization of this genomic test in Taiwanese patients. Materials and Methods: We compiled data on the recurrence score (RS) and clinicopathological characteristics of patients who received the 21-gene assay between August 2016 and August 2021. Survival outcomes were analyzed using the Kaplan–Meier method and log-rank test. Correlations between clinicopathological characteristics and RSs were analyzed using the Chi-square test or Fisher's exact test. Results: Of the 106 recruited patients, 34 and 72 were classified into different risk groups using conventional and Trial Assigning Individualized Options for Treatment (TAILORx)-based cutoff points, respectively. In the conventional stratification group, 61.8%, 29.4%, and 8.8% of the patients were classified into the low-risk (RS: 0–17), intermediate-risk (RS: 18–30), and high-risk (RS: 31–100) categories, respectively. In the TAILORx stratification group, 18.1%, 72.2%, and 9.7% of the patients were classified into the low-risk (RS: 0–10), intermediate-risk (RS: 11–25), and high-risk (RS: 26–100) categories, respectively. In survival analysis, recurrence-free survival did not significantly differ among discrete risk categories. The high-risk category determined using TAILORx-based cutoff points was associated with the presence of >14% Ki-67-positive cells (P = 0.004) and tumor histology Grade III (P = 0.001). Conclusion: Using the Oncotype DX assay, we classified a small proportion of our Taiwanese patients into the high-risk category; no survival difference was observed among the patients in distinct risk categories. These results suggest the clinical utility of the 21-gene assay in Taiwanese patients with early HR+/HER2−breast cancer.

Background: Chromosomal instability (CI) is critical for carcinogenesis. The morphological markers of CI include multipolar mitosis (MPM), chromatin bridge (CB), micronuclei (MN), and nuclear bud (NB). These represent an underlying genetic instability and can be studied in routine cytological specimens. The aim of this study was to evaluate the significance of morphological markers of CI in differentiating malignant and benign effusion smears. Materials and Methods: In this retrospective observational pilot study, 25 cases of benign and 25 cases of malignant effusion smears were selected. All of the malignant cases were reconfirmed by histopathology for primary sites. One thousand cells in May–Grunwald–Giemsa-stained smears were counted for MPM, CB, MN, and NB. The significance of these markers of CI was compared between the benign and malignant cases. Results: The mean numbers of MPM, CB, MN, and NB in malignant cases were 10.52, 7.72, 1.36, and 0.40 per 1000 cells counted, compared to 0.7, 0.5, 0.3, and 0 per 1000 cells counted in benign cases, respectively. The Student's t-test showed highly significant differences between the benign and malignant effusion smears for the CI markers, with P < 0.000001, < 0.000001, and <0.00001 for MN, NB, and MPM, respectively. Conclusion: There were significant differences in the scores of morphological markers of CI in cytological smears between malignant and benign effusions. This is a convenient and reliable method to differentiate between malignant and benign effusions and can be used in conjunction with cytomorphology if a larger study is able to establish the significance in effusions.

Poorly differentiated neuroendocrine carcinoma of the gallbladder is an aggressive and extremely rare type of neuroendocrine tumor. The clinical presentations in most cases are nonspecific, resulting in patients being diagnosed at an advanced stage of the disease. Herein, we report our experience with the case of a 63-year-old woman with no comorbidities who underwent radical resection for a diagnosed gallbladder mass. Abdominal computed tomography scans and magnetic resonance cholangiopancreatography indicated intraluminal masses in the gallbladder with liver invasion. Histologically, the mass was composed of solid sheets of poorly differentiated carcinoma cells with hyperchromatic nuclei; a high Ki-67 index of approximately 80%. The cells were positive for chromogranin A and synaptophysin, and small-cell-type neuroendocrine carcinoma was diagnosed. Postoperatively, she underwent adjuvant chemotherapy with four cycles of cisplatin/etoposide chemotherapy and was disease-free 16 months after surgical treatment with normal hormone-specific markers.

Primary signet-ring cell carcinoma of the appendix is extremely rare, and because the symptoms are vague and nonspecific, obtaining a preoperative diagnosis is difficult. It cannot be detected using imaging modalities because its radiologic features are undefined, and its appearance on both computed tomography and ultrasound images is similar to that of nontumorous appendicitis. Usually, a diagnosis is made after surgery for other diseases involving the removal of the appendix. The right hemicolectomy is suggested for invasive adenocarcinoma; however, diagnosing primary signet-ring cell carcinoma before surgery and managing tumors with adequate surgical resection remain challenging. We present a case of a large ovarian tumor with peritoneal carcinomatosis diagnosed with advanced ovarian cancer but subsequently revealed through pathology to be primary appendiceal signet-ring carcinoma. Detecting appendiceal signet-ring carcinoma warrants additional surgical management, and treating it involves chemotherapy. This rare disease should be kept in mind when encountering abdominal right lower quadrant pain and tumors to allow for a full treatment plan.

We report a case of a perivascular epithelioid cell tumor occurring in the falciform ligament of an otherwise healthy 32-year-old woman. The mass was hypervascular with central necrosis on computed tomography (CT) and contrast-enhanced ultrasound. Our case is unique as CT and ultrasound revealed a paraumbilical vein arising from the expected location in the fissure for the falciform ligament and terminating in the superior aspect of the mass. The vascular anatomy of a recanalized paraumbilical vein, typically associated with portal hypertension, was complete with drainage of blood from the inferior aspect of the mass through the inferior epigastric veins to the femoral veins. The patient had no evidence of liver disease or portal hypertension.

Secondary malignancy of donor origin in the form of acute lymphoblastic leukemia (ALL), post-allogeneic hematopoietic stem cell transplant (HSCT) for beta thalassemia (BT) major, is exceedingly rare. A10 year old male child, the first and only product of non-consanguineous conception, was diagnosed with BT major at the age of 9 months when he had diarrhea and his parents (both of whom had thalassemia minor) noticed yellowing of the skin. Until the age of 10 years, he received regular blood transfusion and iron chelation, when the requirements got escalated and he consequently had to undergo myeloablative haploidentical HSCT from his mother. The post-transplant period was uneventful, and follow up with short tandem repeat chimerism analysis revealed complete donor chimerism on all occasions. Five years after the transplant, he developed fever with pancytopenia. Peripheral smear (PS) and bone marrow revealed blasts that were immunophenotypically precursor B-ALL. Cytogenetics revealed twenty diploid female metaphases with modal karyotype 46, XX[20], and again, complete donor chimerism was noted. Thus, a diagnosis of donor cell leukemia (DCL) was considered. Induction chemotherapy was initiated; however, the patient succumbed to systemic sepsis midway through induction therapy. No evidence of leukemia was noted in the patient's mother, who was followed up with PSs for 5 years. DCL has a poor prognosis. Greater understanding of the disease biology could allow for appropriate donor screening, notification and shielding the recipient from DCL and its grave consequences.

Liposarcoma is a heterogeneous cancer that typically presents at an advanced stage, which leads to a poor prognosis, especially when it is located in the retroperitoneum. Although there are plenty of treatment strategies for liposarcoma, surgery is currently the primary therapeutic choice. Several cases of dedifferentiated liposarcomas that were masquerading as inflammatory pseudotumor have been previously reported, and this contributes to the diagnostic challenge. Many studies have suggested that inflammatory pseudotumor is a type of neoplasm or cancerous process. The use of immunostaining and genetic testing would be very helpful for making a correct diagnosis. Here we present the case of a recurrent tumor located in the retroperitoneum. The patient was initially diagnosed with an inflammatory pseudotumor and then a dedifferentiated liposarcoma following their second presentation.

Spindle cell melanoma (SCM) is a rare morphological subtype of mucosal melanoma, especially located in the lower rectal or anal region. The diagnosis of SCM is challenging because it may share some morphological and immunohistochemical features with desmoplastic melanoma or other malignant tumors. Anorectal melanoma is characterized by aggressive biological behavior, a high incidence of local recurrence and metastasis, and poor outcomes. We herein report a 56-year-old female patient with a challenging diagnosis of primary rectal SCM with a poor prognosis and review the literature.

We report the case of a 68-year-old male with mechanical small bowel obstruction complicated by metastasis of nasal cavity basal cell adenocarcinoma (BCAC). The initial presentation included intermittent abdominal cramping pain and postprandial vomiting. We performed diagnostic laparoscopy under the impression of small bowel obstruction and noticed a tumor located at the terminal ileum. Tumor excision and end-to-end intestinal anastomosis were performed, and pathology reports confirmed the diagnosis of metastatic BCAC. A literature review revealed that small bowel metastatic tumors are rarely caused by BCAC, and that distant metastases of BCAC are also rare. Being aware of this rare disease may lead to an earlier correct diagnosis of small bowel obstruction due to a metastatic tumor.