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Year : 2015  |  Volume : 6  |  Issue : 6  |  Page : 436-438  

Aneurysmal benign fibrous histiocytoma presenting as a giant acrochordon on thigh

Department of Dermatology, Medical College and Hospital, Kolkata, West Bengal, India

Date of Web Publication17-Nov-2015

Correspondence Address:
Anupam Das
“Prerana” 19, Phoolbagan, Kolkata - 700 086, West Bengal
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/2229-5178.169740

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How to cite this article:
Das A, Das A, Bandyopadhyay D, Mishra V, Saha A. Aneurysmal benign fibrous histiocytoma presenting as a giant acrochordon on thigh. Indian Dermatol Online J 2015;6:436-8

How to cite this URL:
Das A, Das A, Bandyopadhyay D, Mishra V, Saha A. Aneurysmal benign fibrous histiocytoma presenting as a giant acrochordon on thigh. Indian Dermatol Online J [serial online] 2015 [cited 2021 Jun 19];6:436-8. Available from: https://www.idoj.in/text.asp?2015/6/6/436/169740


Aneurysmal benign fibrous histiocytoma (BFH) of the skin is a distinct but rare variant of BFH with reported incidence of 1.7% of all BFHs. BFH is usually rapidly growing and may attain a very large size.[1] It shows extensive hemorrhage, with prominent cavernous-like pseudovascular spaces that are not lined by endothelial cells.[2] Clinicopathological features of aneurysmal FH is so different from classical fibrous histiocytoma that malignancy is considered in some cases. We present the case of a firm, mildly tender, pedunculated tumoral mass over medial aspect of right thigh in a middle-aged lady that was clinically diagnosed as a giant acrochordon (skin tag). However on histopathology, the mass was found to be aneurysmal BFH.

A 30-year old woman presented with a mildly tender swelling on the medial aspect of her right thigh, since four months. Initially, a pea-sized asymptomatic nodule, the lesion showed a sudden increase in size over the previous one month. Past medical and surgical history was unremarkable. Family history was noncontributory. On examination, a firm, mildly tender pedunculated tumor of 6 cm was present over the medial aspect of right thigh. [Figure 1] The surface of the mass had a bluish tinge, and the surface temperature being slightly increased. There was no other mucocutaneous or systemic abnormality. Clinical differential diagnoses were giant skin tag (acrochordon), isolated plexiform neurofibroma, fibrous tumors, and vascular tumors. Routine biochemistry panel was normal. Venereal Disease Research Laboratory test (VDRL), hepatitis B virus, hepatitis C virus, and HIV serology were nonreactive.
Figure 1: Clinical photograph showing skin-colored pedunculated growth on the thigh. Note the bluish tinge and prominent vessels on the surface of the lesion

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The mass was subjected to excision biopsy. During excision biopsy, 10 mL of brown-colored foul-smelling sticky fluid came out, which was consistent with degenerated and clotted blood and the cut section had a brown appearance. [Figure 2] Microscopically, epidermis was hyperplastic and acanthotic, rete ridges were flattened. The tumoral mass was present in the deep dermis and there was clear (Grenz) zone just beneath the basement membrane. The dermis showed fibroblast-like spindle cells, histiocytes, and presence of large, blood-filled tissue spaces. Spindle cells were arranged in storiform pattern. Some of the blood-filled tissue spaces lacked an endothelial lining, being surrounded and lined by histiocytes. [Figure 3] and [Figure 4] Immunohistochemistry could not be performed on account of nonavailability of resources and financial constraints. Based on the clinicopathological correlation, a diagnosis of aneurysmal benign fibrous histiocytoma (BFH) was made for our patient. She is under periodic follow-up for detection of recurrence of the disease. However, the postoperative period of six months till date has remained uneventful.
Figure 2: Photograph of excised mass showing brown-colored sticky fluid suggestive of degenerated and clotted blood

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Figure 3: Photomicrograph showing dermal mass composed of fibroblast-like spindle cells and histiocytes arranged in a storiform pattern. Note the spaces lined by endothelial cells (hematoxylin and eosin, H and E, 40×) (a) and showing blood-filled spaces, which are not lined by endothelial cells. (H and E, 40×) (3b)

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Figure 4: Photomicrograph showing dermal mass composed of fibroblast-like spindle cells and histiocytes arranged in a storiform pattern. (H and E, 100×)

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Fibrous histiocytoma (FH) is a benign dermal and often superficial subcutaneous proliferation of oval cells resembling histiocytes, and spindle-shaped cells resembling fibroblasts and myofibroblasts. The line of differentiation remains uncertain, but these lesions are classified as fibrohistiocytic tumors because of the microscopic appearance of the tumor cells. A number of clinicopathological variants of FH have been described. These variants include cellular FH, aneurysmal FH, atypical FH (pseudosarcomatous FH, dermatofibroma with monster cells), epithelioid FH, and atrophic FH.[2] Today, this entity is no longer termed “malignant” due to its benign microscopic appearance and favorable prognosis.[3] Besides, the 2002 World Health Organization (WHO) classification removed it from the malignant FH subtype of sarcoma (now synonymous with undifferentiated pleomorphic sarcoma) and placed it under the category of tumors of uncertain differentiation as angiomatoid FH.

Aneurysmal BFH, was first described by Santa Cruz and Kyriakos in 1981. AFH is a neoplasm that most commonly affects children and young adults. The tumor is rare, accounting for approximately 0.3% of all soft tissue neoplasms; however, the incidence may be underestimated due to overlapping histopathological findings. It most commonly arises in sites of normal lymphoid tissue such as the antecubital fossa, axilla, inguinal and supraclavicular regions. The majority of cases occur in the extremities, although cases have been reported in the head and neck region (10%) and trunk. Our patient presented with a mass on the medial aspect of the right thigh, consistent with the majority of the presentations described in the literature.

It usually presents as painless, slow growing mass within the deep dermis and subcutaneous tissue.[4] A small proportion of patients experience systemic symptoms, including pyrexia, anemia, and malaise, suggesting tumoral cytokine production. Symptoms of pain and tenderness are rarely encountered. In our case, the lesion was asymptomatic at the outset. However, there was a sudden increase in the size of the lesion owing to intralesional hemorrhage. Clinically, it has varied appearances and mimics benign and malignant vascular tumors and fibrous tumors resulting in diagnostic difficulties. Clinically, it differs from ordinary BFH by larger than average size, rapid growth due to intralesional hemorrhage and pigmentation. The lesion may mimic fibrous tumors such as fibroxanthoma and vascular tumor, and histopathological examination is mandatory for diagnosis.

The main histopathological criteria for diagnosing this lesion is presence of blood-filled spaces simulating artifactual clefts or cavernous vascular channels within an ordinary FH. Aneurysmal variant of FH has to be differentiated from atypical fibroxanthoma, angiomatoid malignant FH (angiomatoid MFH), and vascular tumors such as nodular Kaposi's sarcoma and spindle cell angiosarcoma.[5] Angiomatoid MFH occurs at younger age and is composed of monomorphic round cells with prominent lymphohistiocytic infiltrate. Nodular Kaposi's sarcoma shows CD34 positive cells lining slit-like spaces containing red blood cells. Cutaneous spindle cell angiosarcomas occur exclusively on face and scalp and have vascular spaces lined by atypical, mitotically active endothelial cells. We could not however perform immunohistochemistry due to nonavailability of resources.

The cumulative findings of a meta-analysis of multiple studies designed to calculate the malignant potential of aneurysmal BFH demonstrate that the majority of patients (73.2%) are disease free after local excision and a minority (23.2%) develop recurrent disease and 8.7% develop metastatic disease within 24 months post-surgery. The overall mortality rate is 4.3%; however, this could be underestimated due to short follow-up periods. Although the tumor is often termed to have a low malignant potential lesion in the literature, it is officially classified as being of intermediate malignant potential. The clinical behavior of the tumor cannot be predicted by clinical or histiological parameters. However, the development of both local recurrence and metastases has shown a correlation with invasion into the deep fascia or muscle as assessed surgically. Treatment is surgical resection.

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   References Top

Calonje E, Fletcher CD. Aneurysmal benign fibrous histiocytoma: Clinicopathological analysis of 40 cases of a tumourfrequently misdiagnosed as a vascular neoplasm. Histopathology 1995;26:323-31.  Back to cited text no. 1
Calonje E. Soft-tissue tumours and tumour-like conditions. In: Burns T, Breathnach S, Cox N, Griffiths C, editors. Rook's Textbook of Dermatology. 8th ed. Oxford: Wiley-Blackwell; 2010. p. 56.16-20.  Back to cited text no. 2
Matushansky I, Charytonowicz E, Mills J, Siddiqi S, Hricik T, Cordon-Cardo C. MFH classification: Differentiating undifferentiated pleomorphic sarcoma in the 21st century. Expert Rev Anticancer Ther 2009;9:1135-44. 333  Back to cited text no. 3
Antonescu CR, Dal Cin P, Nafa K, Teot LA, Surti U, Fletcher CD, et al. EWSR1-CREB1 is the predominant gene fusion in angiomatoid fibrous histiocytoma. Genes Chromosomes Cancer 2007;46:1051-60. 444  Back to cited text no. 4
Albonico G, Pellegrino G, Maisano M, Africa G, Pedriali M, Nenci I. Aneurysmatic fibrous histiocytoma: Case report and review of the literature. Pathologica 2001;93:136-8. 555  Back to cited text no. 5


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]


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