Myxoid liposarcoma in an 11-year-old patient.

Myxoid liposarcoma is a mesenchymal malignancy that most commonly presents in young adults, with peak incidence between the ages of 30-50 years. The clinical behavior of myxoid liposarcoma has been well characterized in adults. However, little is known about the clinical features and treatment outcomes of myxoid liposarcoma in child, owing to its rarity. This case report describes an 11-year-old previously healthy female who presented with a painless mass in her right thigh. Ultrasonography, computed tomography, and magnetic resonance imaging demonstrated a soft tissue mass with clear margins in the subfascial plane superficial to the gracilis and sartorius muscles. She was diagnosed with myxoid liposarcoma based on histological and molecular cytogenetic examinations of the core-needle biopsy specimen. The patient subsequently underwent wide resection without any adjuvant treatment. The patient has not experienced any symptoms of local recurrence and metastases as of 2.5 years after surgery.

PDGFRB and NOTCH3 Mutations are Detectable in a Wider Range of Pericytic Tumors, Including Myopericytomas, Angioleiomyomas, Glomus Tumors, and Their Combined Tumors.

Pericytic tumors are subclassified as myopericytomas, myofibromas, angioleiomyomas, and glomus tumors according to the current World Health Organization classification. These pericytic tumors form a continuous morphologic spectrum, including those with combined morphology. However, to our knowledge, no widely accepted criteria for classifying tumors with combined morphology are available. Recent studies have identified platelet-derived growth factor receptor-beta (PDGFRB) gene mutations in a subset of myofibromas, myopericytomas, and myopericytomatoses but not in angioleiomyomas. NOTCH receptor 3 (NOTCH3) mutations have been reported in a subset of infantile myofibromatosis. To assess their potential role in classifying pericytic tumors, we investigated PDGFRB and NOTCH3 mutations in 41 pericytic tumors of variable morphology, including some combined forms. Our results show these mutations to be present in a variety of pericytic tumors, such as myopericytomas (PDGFRB, 3/11; NOTCH3, 4/11), myopericytomatoses (1/2; 1/2), myofibromas (3/6; 0/6), angioleiomyomas (2/13; 3/13), and glomus tumors (5/9; 1/9). Point mutations were identified in 3 tumors in PDGFRB exon 12 (Y562C, S574F, and G576S), 12 tumors in PDGFRB exon 14 (M655I, H657L, and N666K), and 9 tumors in NOTCH3 exon 25 (A1480S/T, D1481N, G1482S, T1490A, E1491K, G1494S, and V1512A). All PDGFRB mutations and NOTCH3 G1482S, T1490A, and G1494S mutations were classified as "deleterious/damaging" by ≥4 of 6 pathogenicity prediction tools in silico. Five-mutation-positive tumors, including 1 myopericytoma-angioleiomyoma, 2 myopericytomatoses-myofibroma, 1 myofibroma-myopericytoma and 1 angioleiomyoma-myopericytoma, were of combined morphology. Therefore, we found PDGFRB and NOTCH3 mutations to be detectable in a much wider variety of pericytic tumors than previously reported and confirmed myopericytomas, myofibromas, angioleiomyomas, and glomus tumors as members harboring PDGFRB or NOTCH3 mutations. Our results thus suggest that PDGFRB or NOTCH3 mutations are not useful for subclassifying members of the pericytic tumor family.

An autopsy case of a patient with systemic sclerosis who developed marked pulmonary hypertension because of pulmonary tumor thrombotic microangiopathy caused by gastric carcinoma.

We performed an autopsy on a patient with systemic sclerosis who developed uncontrollable pulmonary hypertension due to pulmonary tumour thrombotic microangiopathy (PTTM) caused by gastric carcinoma. The case was of a 62-year-old woman with systemic sclerosis who was admitted to the intensive care unit (ICU) with severe pulmonary hypertension accompanied by respiratory insufficiency. Pulmonary hypertension could not be controlled despite aggressive medical treatment including vasodilators. Approximately 10 days after admission, a unilateral pleural effusion developed. Thoracentesis was performed, and cytology examination of the pleural fluid revealed carcinomatous pleurisy. Because of the presence of a known gastric carcinoma, PTTM was clinically diagnosed. Although chemotherapy was administered, she died 33 days after ICU admission. An autopsy revealed diffuse fibrocellular intimal thickening of the peripheral pulmonary arterioles, which indicated PTTM. In patients with connective tissue disease complicated with pulmonary hypertension, it is necessary to differentiate not only pulmonary arterial hypertension but also other pathological conditions such as PTTM.