Kaposiform hemangioendothelioma (KHE) is a rare, locally aggressive vascular tumor of intermediate malignancy, predominantly affecting infants and young children. Bone involvement and extension into adjacent soft tissues are uncommon and pose significant diagnostic and therapeutic challenges. We report a 6-year-old boy diagnosed with KHE involving the left hip joint region, iliac bone, and proximal femur. The initial presentation in late 2020 included left lower limb pain, mild swelling, and limited mobility. Imaging studies suggested inflammatory arthritis, but subsequent MRI and histopathological examinations excluded Ewing sarcoma and revealed a spindle-cell vascular proliferation consistent with KHE. Disease progression led to osteolytic changes resembling Gorham–Stout disease. Following multidisciplinary consultations, systemic therapy with Sirolimus was initiated (starting dose 0.7–0.8 mg daily, adjusted to therapeutic levels). Supportive hydration and dietary management were continued. The treatment was well tolerated, with no significant laboratory abnormalities. Serial MRI follow-ups demonstrated a gradual regression of bone and soft-tissue enhancement and no new lesions, indicating partial radiologic remission. Clinically, pain subsided, mobility improved, and no functional impairment was observed at the latest follow-up in October 2025. This case illustrates the clinical efficacy of Sirolimus in achieving disease stabilization and partial regression in bone-involved KHE. Early recognition, accurate histopathological diagnosis, and interdisciplinary management remain critical for optimizing outcomes in pediatric vascular tumors with osseous extension. Read More

Meeting name: SPR 2026 Annual Meeting , 2026

Authors: Osinska Aleksandra, Materniak Andrzej, Wozniak Magdalena

Keywords: Kaposiform Hemangioendothelioma

Selumetinib Therapy for Plexiform Neurofibroma in Neurofibromatosis Type 1: A Case Report Read More

Meeting name: SPR 2026 Annual Meeting , 2026

Authors: Osinska Aleksandra, Machulak Maja, Zwierzchowska Magdalena, Lew Marek, Wozniak Magdalena

Keywords: Neurofibromatosis 1

Tumefactive white matter lesions in pediatric patients represent a significant diagnostic challenge, as their size, mass effect, and contrast enhancement on MRI can closely mimic neoplastic processes. However, they often reflect inflammatory, autoimmune, or demyelinating etiologies rather than true tumors. Early recognition is crucial to avoid unnecessary invasive procedures and to initiate timely immunomodulatory treatment. We present two pediatric patients with acute neurological symptoms and multifocal tumor-like white matter lesions. The first patient, a 17-year-old male, presented with left-sided hemiparesis and multiple lesions involving both cerebral hemispheres. The second patient, a 15-year-old female, presented with acute visual loss and multifocal lesions within the occipital and parietal white matter. Both patients were treated with high-dose corticosteroids and supportive therapy. The second patient additionally received intravenous immunoglobulins and empiric antimicrobial therapy due to initial diagnostic uncertainty. Partial regression of the lesions and clinical improvement were observed in both cases. Tumefactive-like lesions in pediatric patients can closely mimic neoplasms but often show a favorable response to immunomodulatory therapy. Early recognition, multidisciplinary assessment, and close follow-up are essential to optimize clinical outcomes. Read More

Meeting name: SPR 2026 Annual Meeting , 2026

Authors: Osinska Aleksandra, Marchewka Klaudia, Bialek Wiktoria, Lew Marek, Wozniak Magdalena

Keywords: Tumor

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune disorder of the central nervous system characterized by antibodies targeting NMDA receptors. It primarily affects adolescent and young adult females and frequently coexists with ovarian teratoma. The disease often begins with psychiatric symptoms such as agitation, hallucinations, or affective instability, which may delay proper diagnosis and treatment. A 16-year-old girl was admitted to a psychiatric ward due to acute behavioral disturbances and depressive symptoms. Four days after admission, she developed impaired consciousness (GCS 9) and focal neurological signs, including right eye divergent strabismus and bilateral Babinski reflex. Cerebrospinal fluid analysis revealed lymphocytic pleocytosis and elevated protein concentration. Anti-NMDAR antibodies were detected in cerebrospinal fluid. MRI showed hyperintense lesions in the occipital lobes. Abdominal ultrasound identified a right ovarian mass; urgent surgical resection confirmed an immature teratoma. The patient received combined immunotherapy including corticosteroids, intravenous immunoglobulins, plasma exchange, and rituximab. Gradual clinical improvement was observed over subsequent weeks. This case illustrates the complex neuroimmunological interaction between ovarian teratoma and the central nervous system. Psychiatric symptoms were the initial manifestation, delaying recognition of the underlying encephalitis. The presence of anti-NMDAR antibodies in cerebrospinal fluid and identification of ovarian teratoma confirmed the diagnosis. Early tumor resection combined with immunotherapy significantly improves outcomes and reduces neurological sequelae. Acute-onset psychiatric symptoms in adolescent females should prompt consideration of autoimmune encephalitis, especially in the presence of an ovarian mass. Early detection and multidisciplinary management are crucial for full recovery and prevention of long-term complications. Read More

Meeting name: SPR 2026 Annual Meeting , 2026

Authors: Osinska Aleksandra, Wozniak Magdalena, Materniak Andrzej, Wyzkiewicz Karolina, Bialek Wiktoria, Sochocki Radoslaw

Keywords: Testicular Tumor