Pilot Study by Liquid Biopsy in Gastrointestinal Stromal Tumors: Analysis of PDGFRA D842V Mutation and Hypermethylation of SEPT9 Presence by Digital Droplet PCR.

Tissue biopsy remains the standard for diagnosing gastrointestinal stromal tumors (GISTs), although liquid biopsy is emerging as a promising alternative in oncology. In this pilot study, we advocate for droplet digital PCR (ddPCR) to diagnose GIST in tissue samples and explore its potential for early diagnosis via liquid biopsy, focusing on the PDGFRA D842V mutation and SEPT9 hypermethylated gene. We utilized ddPCR to analyze the predominant PDGFRA mutation (D842V) in surgical tissue samples from 15 GIST patients, correlating with pathologists' diagnoses. We expanded our analysis to plasma samples to compare DNA alterations between tumor tissue and plasma, also investigating SEPT9 gene hypermethylation. We successfully detected the PDGFRA D842V mutation in GIST tissues by ddPCR. Despite various protocols to enhance mutation detection in early-stage disease, it remained challenging, likely due to the low concentration of DNA in plasma samples. Additionally, the results of Area Under the Curve (AUC) for the hypermethylated SEPT9 gene, analyzing concentration, ratio, and abundance were 0.74 (95% Confidence Interval (CI): 0.52 to 0.97), 0.77 (95% CI: 0.56 to 0.98), and 0.79 (95% CI: 0.59 to 0.99), respectively. As a rare disease, the early detection of GIST through such biomarkers is particularly crucial, offering significant potential to improve patient outcomes.

Epstein-Barr virus-positive mucocutaneous ulcer in a patient with ulcerative colitis: a recently described entity to take into account.

Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) is a new entity recently included in the classification of B-cell lymphoproliferative disorders associated with Epstein-Barr virus (EBV). It is related to immunosuppression and it usually appears in the oropharynx or the skin, being the colon an uncommon location. We present the case of a 31-year-old man with ulcerative proctitis being treated with azathioprine (AZA) and adalimumab (ADA), who was admitted to the hospital due to suspicion of a moderate-severe flare of ulcerative proctitis. Microbiological stool analyses were negative, with a positive fecal calprotectin test (2700 mg/kg). Rectoscopy showed severe endoscopic activity, taking multiple biopsies. Intravenous steroids were started at a dose of 60 mg/day. He presented a favorable clinical and analytical evolution, being discharged from the hospital. The histological results were received at gastroenterology consultation, being compatible with EBVMCU. AZA and ADA were withdrawn, whereas descending steroid regimen and oral and topical mesalazine were continued, being the clinical response adequate.

Depósito de lantano en la mucosa gástrica de paciente con enfermedad renal crónica / Deposits of lanthanum in the gastric mucosa of a patient with chronic kidney disease

El carbonato de lantano es un quelante de fósforo no cálcico utilizado en el tratamiento de la hiperfosfatemia asociada a la enfermedad renal crónica. Los depósitos de lantano en la pared gastrointestinal han sido descritos desde 2015. Su significado clínico es incierto. Describimos un caso de paciente varón de 62 años con enfermedad renal crónica en tratamiento con carbonato de lantano durante 3 años, quien presentó depósitos en la mucosa gástrica biopsiada por dispepsia. Los depósitos se observaban como material acelular, con formas irregulares, rodeados de macrófagos y con reacción gigantocelular. Se confirmó la presencia de lantano en los depósitos mediante estudio de espectroscopia de rayos X. En su diagnóstico diferencial con otros depósitos, la clave para hacer su correcta identificación es la realización de una detallada historia clínica que incluya medicamentos administrados y el conocimiento de su aspecto microscópico

Lanthanum carbonate is a non-calcium phosphorus chelator used in the treatment of hyperphosphatemia associated with chronic renal disease. Deposits of lanthanum in the gastrointestinal wall have been recently described but its clinical significance is uncertain. We present a case of a 62-year-old male with chronic renal disease treated with lanthanum carbonate for 3 years, with deposits in his gastric mucosa, found on biopsy for dyspepsia. The deposits were acellular and of irregular shape, surrounded by macrophages and foreign body giant cells. The presence of lanthanum in the deposits was confirmed by X-ray spectroscopy. Diagnosis is reached with knowledge of its microscopic appearance and a thorough clinical history

[Deposits of lanthanum in the gastric mucosa of a patient with chronic kidney disease]. / Depósito de lantano en la mucosa gástrica de paciente con enfermedad renal crónica.

Lanthanum carbonate is a non-calcium phosphorus chelator used in the treatment of hyperphosphatemia associated with chronic renal disease. Deposits of lanthanum in the gastrointestinal wall have been recently described but its clinical significance is uncertain. We present a case of a 62-year-old male with chronic renal disease treated with lanthanum carbonate for 3 years, with deposits in his gastric mucosa, found on biopsy for dyspepsia. The deposits were acellular and of irregular shape, surrounded by macrophages and foreign body giant cells. The presence of lanthanum in the deposits was confirmed by X-ray spectroscopy. Diagnosis is reached with knowledge of its microscopic appearance and a thorough clinical history.

Cytology of extramammary Paget's disease of the vulva. A case report.

BACKGROUND: Paget's disease of the vulva (PDV) is a rare entity, with only a few cytologic descriptions having been published on it. Diagnosis is usually delayed because it is often clinically mistaken for some types of dermatosis, and biopsy is usually postponed. CASE: A 56-year-old woman presented with a pruritic, erythematous and ulcerated superficial lesion on the right labium majus of approximately eight months' duration. A vulvar cytologic smear showed a bloody and inflammatory background with many single malignant cells; scarce malignant cell aggregates; and abundant, mature squamous and dyskeratotic cells. The tumor cells were large, with a frequently eccentric, large nucleus. Some binucleated forms were noted. Nucleoli were rare. Cytoplasm varied from pale and delicate to densely basophilic. Intracytoplasmic vacuoles were very rare. Tumor cell aggregates were small and exhibited pseudocannibalism. Short strands of malignant cells arranged in an Indian file pattern were also evident. Histologic examination of a wedge biopsy, wide local excision of the lesion and simple vulvectomy showed PDV. CONCLUSION: Knowledge of the cytologic features of PDV could provide a highly probable cytologic diagnosis of the disease and should alert the clinician to the need for immediate biopsy. Systematic collecting of smears from any eczematous change in the vulva should be considered a first step to early diagnosis of malignancy.