Histiocytoma angiomatous fibrous C49.9

Enzinger 1979

Mostly subcutaneous, non-painful, pseudoangiomatous, low-grade malignant tumor node, which occurs in a localized manner in the extremities, especially in children and young adults. Clinically, the tumour is usually confused with an older haematoma (ask exact age!).

Rare is the primary occurrence of the tumor in other organs (lung, mediastinum, ovaries, vulva)

Angiomatous fibrous histiocytoma belongs to a group of soft tissue tumors that exhibit a translocation of the Ewing sarcoma breakpoint 1 gene (EWSR1 ). EWSR1 is located on chromosome 22q12. Several partner genes are involved in the fusion (e.g. CREB1). This translocation is neither tissue-specific nor does it predict a specific biological pattern. The detection of an EWSR1-ATF1 fusion is rarer. (Note: EWSR1-ATF1 fusion has been identified as the most common genetic abnormality in clear cell soft tissue sarcomas ).

f>m; mainly children, adolescents and younger adults are affected; average age of onset: 20 years; 3-67 years.

groin, knee, elbow

Clinically, a few months old, uncharacteristic, easily delimited, fixed subcutaneous nodule, which is predominantly localized on the lower extremity (more rarely on the upper extremity and other localizations) and which can be moved over its base. As the tumour can shimmer bluish through the skin, it is more often misjudged as an older haematoma.

System signs such as fever and an increase in inflammation parameters (?) may occur.

Subcutaneous, usually well-demarcated nodule consisting of proliferations of spindle to epithelioid cells surrounding a pseudoangiomatous, blood-filled space. Focal hemosiderin deposits. Only minor cellular atypia, rarely mitoses. Tumor cells respond positively to desmin, CD68, CD99, EMA. S-100 protein, CD34 and pancytokeratin are not expressed. Longer existing tumors show an increasing fibrosis of the parenchyma. Cytogenetic pathologies are observed in a majority of tumors: t(2;22) (q32.3;q12) translocation with an EWSR1-CREB1 fusion (EWSR1= Ewing sarcoma breakpoint 1 gene). The translocation t(2;22)(q13;q12) with an EWSR1-ATF1 fusion is rarer.

Dermatofibrosarcom protuberans, hemangiopericytoma, atypical fibroxanthoma

Cheap. The bulge tends to local recurrence (about 2-10% of cases). Metastasis formation is expected in <1% of cases.

1. Bohelay G et al(2015) Angiomatoid fibrous histiocytoma in children: 6 cases. Ann Dermatol Venereol 142:541-548
2. Enzinger FM (1979) Angiomatoid fibrous histiocytoma. A distinct fibrohistiocytic tumor of children an adults simulating a vascular neoplasm, Cancer 44: 2147-2157
3. Kong X et al (2014) Recurrent painful perianal subcutaneous angiomatoid fibrous histiocytoma: a case report and review of the literature. Medicine (Baltimore) 93: e202
4. Tataroğlu C et al (2015) Angiomatoid fibrous histiocytoma: case report and review of the literature. Turk J Pediatr 57:102-104
5. Thway K et al (2012) Tumors with EWSR1-CREB1 and EWSR1-ATF1 fusions: the current status. Am J Surg Pathol 36: e1-e11
6. Thway K et al (2015) Angiomatoid fibrous histiocytoma: the current status of pathology and genetics. Arch Pathol Lab Med 139:674-682
7. Wilk M et al (2015) Angiomatous fibrotic histiocytoma case series with emphasis on the late fibrotic variant. JDDG 13: 441-449