Primary classical seminoma of the testis with rhabdoid differentiation

Rhabdoid differentiation is an indicator of poor prognosis that is often seen in renal cell carcinoma; however, it is also rarely seen in non-renal tumours. Therefore, pathologists should carefully review this finding and report. This report describes the first case of a seminoma of testicular origin that developed rhabdoid differentiation.

Undifferentiated carcinoma of the transverse colon with rhabdoid features that developed during treatment of non-small cell lung carcinoma with pembrolizumab: a case report

BACKGROUND

Undifferentiated carcinoma of the colon is rare, and its prognosis is very poor. We report a case of undifferentiated carcinoma of the colon with rhabdoid features developed during treatment of non-small lung carcinoma (NSCLC) with pembrolizumab.

CASE PRESENTATION

A 58-year-old man was diagnosed with transverse colon cancer during chemotherapy with pembrolizumab for NSCLC. Laparoscopic right hemicolectomy was performed. The histopathological diagnosis was undifferentiated carcinoma with rhabdoid features and lymph node metastasis. Immunohistochemically, programmed death ligand 1 (PD-L1) showed positivity. The microsatellite instability (MSI) status was low. He continued to receive pembrolizumab for NSCLC, and there have been no signs of colon cancer recurrence and progression of NSCLC for 15 months.

CONCLUSION

We present the case of an undifferentiated carcinoma of the transverse colon with rhabdoid features. The development of the tumor with the expression of PD-L1 during pembrolizumab might have been associated with the low MSI.

Intestinal undifferentiated carcinoma in a red-crowned crane (Grus japonensis)

A 33-year-old red-crowned crane (Grus japonensis) had a diffuse intestinal thickening from the duodenum to colon. Microscopically, neoplastic cells were arranged in sheets and occasionally nests or cords without gland or squamous differentiation. Metastatic tumor cells were found in the lungs, heart, kidneys and adrenal glands. Immunohistochemically, the neoplastic cells were strongly positive for pan-cytokeratin and cytokeratin 8 and 18 and only partly positive for E-cadherin antibodies. Immunostaining for CD3 was positive in normal lymphocytes, and NSE was also positive in normal nerve fibers. But, the neoplastic cells were not immunoreactive to CD3 and NSE. Based on the histological features and the epithelial characteristics in the immunohistochemical stain, the present case was diagnosed as undifferentiated carcinoma originating from the intestine. Interestingly, the neoplastic cells showed a unique growth pattern; they never invaded the submucosa or muscularis throughout the intestine, whereas they spread lymphogenously or hematogenously to other organs.

Malignant rhabdoid tumors of the liver: an exceptional tumor in adults - a case report and literature review

Malignant rhabdoid tumor (MRT) is a very rare liver tumor, with only a few cases reported in the literature. MRT generally occurs in pediatric patients and prognosis is usually very poor. Here we report a very rare case of MRT occurring in a young adult who is still alive with no sign of recurrence at 41 months of follow-up. MRI and computed tomography scans revealed a voluminous heterogeneous mass in the left liver with no specific pattern. The mass included necrotic and fibrous components. Histology showed fusiform, loosely cohesive cells with abundant eosinophilic cytoplasm resulting in eccentric nuclei, thus creating the characteristic rhabdoid appearance. Immunohistochemical studies revealed a lack of nuclear INI1 protein expression. The patient's treatment included a major left liver resection associated with chemotherapy. A thorough search of the literature revealed one case of MRT in a young adult who died at 48 months of follow-up. A less malignant nature of the tumor in young adults may be suspected, but a longer disease-free survival may also be the fruit of aggressive surgical and oncological treatment.