Case report: Molecular profiling facilitates the diagnosis of a challenging case of lung cancer with choriocarcinoma features

Accurate diagnoses are crucial in determining the most effective treatment across different cancers. In challenging cases, morphology-based traditional pathology methods have important limitations, while molecular profiling can provide valuable information to guide clinical decisions. We present a 35-year female with lung cancer with choriocarcinoma features. Her disease involved the right lower lung, brain, and thoracic lymph nodes. The pathology from brain metastasis was reported as "metastatic choriocarcinoma" (a germ cell tumor) by local pathologists. She initiated carboplatin and etoposide, a regimen for choriocarcinoma. Subsequently, her case was assessed by pathologists from an academic cancer center, who gave the diagnosis of "adenocarcinoma with aberrant expression of β-hCG" and finally pathologists at our hospital, who gave the diagnosis of "poorly differentiated carcinoma with choriocarcinoma features". Genomic profiling detected a KRAS G13R mutation and transcriptomics profiling was suggestive of lung origin. The patient was treated with carboplatin/paclitaxel/ipilimumab/nivolumab followed by consolidation radiation therapy. She had no evidence of progression to date, 16 months after the initial presentation. The molecular profiling could facilitate diagnosing of challenging cancer cases. In addition, chemoimmunotherapy and local consolidation radiation therapy may provide promising therapeutic options for patients with lung cancer exhibiting choriocarcinoma features.

Case Report: a rare primary gastric choriocarcinoma revealed on 18F-FDG PET/CT

Choriocarcinoma is an exceptionally aggressive trophoblastic cell tumor that that typically originates in gonadal tissues, with rare occurrences outside the gonads, including the mediastinum, retroperitoneum, and intracranial sites. However, it rarely occurs in the stomach. Herein, we presented a case of primary gastric choriocarcinoma in a 27-year-old female patient who found multiple liver masses detected during physical examination, accompanied by remarkably elevated human chorionic gonadotropin levels. The 18F-FDG PET/CT scan suggested ring-shaped intense uptake masses located in the gastric sinus and liver, and no significance in the pelvic region. Final histopathology indicated primary choriocarcinoma of the stomach. This case illustrates that 18F-FDG PET/CT is an essential imaging technique for the clinical diagnosis and stage of primary choriocarcinoma.

Urothelial Carcinomas With Trophoblastic Differentiation, Including Choriocarcinoma: Clinicopathologic Series of 16 Cases

Trophoblastic differentiation (including choriocarcinoma) arising in urothelial carcinoma has been described in numerous case reports, but never in a single series. We present a series of these tumors, describing the morphologic spectrum, applying traditional and novel immunohistochemical stains, and characterizing clinical follow-up. We identified 16 cases, arising predominantly in the bladder (N=14), but also the ureter (N=1) and prostatic urethra (N=1). Six of our cases (38%) contained invasive urothelial carcinoma with admixed syncytiotrophoblasts, 8 cases (50%) consisted of invasive urothelial carcinoma with choriocarcinoma, 1 case (6%) showed urothelial carcinoma in situ with associated choriocarcinoma, and 1 case (6%) consisted of pure choriocarcinoma. Other subtypes of variant morphology were seen in 5 of our cases (31%) and included squamous, glandular, lipoid, chordoid/myxoid, and sarcomatoid features. Given the limited specificity of human chorionic gonadotropin immunohistochemistry, we also studied the expression of a novel specific trophoblastic marker, hydroxyl-δ-5-steroid dehydrogenase, as well as Sal-like protein 4. Human chorionic gonadotropin expression was seen in nearly all cases (93%) but was often not limited to the trophoblastic component, staining the urothelial component also in 85% of the cases. Expression of hydroxyl-δ-5-steroid dehydrogenase was more sensitive and more specific, staining 100% of the cases and limited to trophoblasts in all but 1 case. Sal-like protein 4 expression was variable, staining trophoblast in only 50% of cases and staining the urothelial carcinoma component in 43% of those positive cases. Most of our tumors presented at a high stage and were associated with poor clinical outcomes, with at least muscle-invasive disease (pT2) in 10 of the 14 bladder tumors (71%), periureteric fat invasion in the ureter tumor (pT3), distant metastases in 7 of 16 cases (44%) and death of disease in 3 of the 15 patients with follow-up (20%). Our study describes a series of urothelial carcinomas with trophoblastic differentiation, demonstrating the morphologic spectrum of this entity, its frequent association with other subtypes of variant morphology, its characteristic immunoprofile, and its aggressive clinical behavior.