Alaggio Rita, Barisani Donatella, Ninfo Vito, Rosolen Angelo, Coffin Cheryl M
Dipartimento di Scienze Oncologiche e Chirurgiche Azienda Ospedaliera-Università di Padova, Padova, Italy.
Pediatr Dev Pathol. 2008 Sep-Oct;11(5):355-62. doi: 10.2350/07-09-0355.1. Epub 2008 Feb 14.
Infantile myofibromatosis (IM) is a distinctive mesenchymal disorder with different clinical forms, including solitary, multicentric, and generalized with visceral involvement. A wide morphologic spectrum is encountered, with the extremes resembling congenital infantile fibrosarcoma (CIFS) and infantile hemangiopericytoma. We report a series of lesions with mixed features of CIFS and IM and compare them in order to further define their clinicopathologic features and the significance of the so-called composite fibromatosis. Seven lesions with unusual overlapping morphologic "composite" features of both IM and CIFS were selected from a series of 106 myofibroblastic lesions. Three cases classified as composite infantile myofibromatoses (COIM) were highly cellular tumors with a diffuse growth of primitive mesenchymal cells and focal features of IM combined with areas resembling infantile fibrosarcoma (IF). Four cases were classified as IF. Three of these exhibited a biphasic pattern with foci resembling IM, including whorls of primitive and spindle cells and perivascular and intravascular projections of myofibroblastic nodules, and the 4th had a close histologic resemblance to a primitive, immature IM. With reverse transcriptase polymerase chain reaction, the ETV6-NTRK3 transcript was absent in 3 COIM and was detected in 3 CIFS; the other CIFS had typical cytogenetic aberrations. On the basis of currently available information, COIM represents a morphologic variant of IM that can mimic IF. Careful histologic evaluation to detect the typical features of IM is essential to avoid classification as IF. Molecular analysis for the ETV6-NTRK3 gene fusion is an important diagnostic tool in this group of lesions.
婴儿肌纤维瘤病（IM）是一种独特的间叶组织疾病，有不同的临床形式，包括孤立性、多中心性以及累及内脏的全身性病变。其形态学表现多样，极端情况类似先天性婴儿纤维肉瘤（CIFS）和婴儿血管外皮细胞瘤。我们报告了一系列具有CIFS和IM混合特征的病变，并对其进行比较，以进一步明确其临床病理特征以及所谓复合性纤维瘤病的意义。从106例肌成纤维细胞性病变中选取了7例具有IM和CIFS不寻常重叠形态学“复合”特征的病变。3例被归类为复合性婴儿肌纤维瘤病（COIM）的病例是细胞丰富的肿瘤，原始间叶细胞呈弥漫性生长，具有IM的局灶性特征，并伴有类似婴儿纤维肉瘤（IF）的区域。4例被归类为IF。其中3例表现为双相模式，有类似IM的病灶，包括原始细胞和梭形细胞的漩涡以及肌成纤维细胞结节的血管周围和血管内突起，第4例在组织学上与原始、未成熟的IM非常相似。通过逆转录聚合酶链反应，3例COIM中未检测到ETV6-NTRK3转录本，3例CIFS中检测到该转录本；其他CIFS有典型的细胞遗传学异常。根据现有信息，COIM是IM的一种形态学变异，可模仿IF。仔细的组织学评估以检测IM的典型特征对于避免误诊为IF至关重要。对ETV6-NTRK3基因融合进行分子分析是这组病变的重要诊断工具。
