Targetoid Hemosiderotic Hemangioma

Updated: Mar 05, 2018
  • Author: J Andrew Carlson, MD; Chief Editor: Dirk M Elston, MD  more...
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In 1988, Santa Cruz and Aronberg [1] first described targetoid hemosiderotic hemangioma (THH), which is a benign vascular neoplasm that some have postulated may represent a reactive condition. [2] Also termed hobnail hemangioma, targetoid hemosiderotic hemangioma typically presents as a solitary papule affecting the limbs or trunk of young or middle-aged people. Recognition of characteristic features is important to avoid misdiagnosis, as clinically and histopathologically, targetoid hemosiderotic hemangioma can mimic disorders such as melanoma, Kaposi sarcoma (KS), and angiosarcoma. Note the images below.  Because the histology of targetoid hemosiderotic hemangioma is reproducible, its clinical features variable, and the hobnail phenomenon not specific, some authors favor the designation of "superficial hemosiderotic lymphovascular malformation" instead of HH or targetoid hemosiderotic hemangioma. [3]

Most targetoid hemosiderotic hemangiomas do not ex Most targetoid hemosiderotic hemangiomas do not exhibit a targetoid appearance. An older waning lesion is presented showing a 2-toned papule with a dark brown center surrounded by a tan-brown rim. This clinical image can be confused with a melanocytic nevus or dermatofibroma. This 20-year-old patient described episodic changes that varied from a larger violaceous papule surrounded by an erythematous halo (target lesion) to the illustrated lesion.
Targetoid hemosiderotic hemangioma mimicking nodul Targetoid hemosiderotic hemangioma mimicking nodular malignant melanoma. Note the dark black papule surrounded by a faint brown rim.


The exact pathogenesis of targetoid hemosiderotic hemangioma (THH) is unknown, but some authorities have postulated trauma to lymphatic vessels with development of lymphatic-vascular microshunts play a key role in the pathogenesis of the defining features of targetoid hemosiderotic hemangioma: dilated vascular spaces with hobnailed endothelial cells, extravasation of red blood cells and hemosiderin deposits, fibrosis, and inflammation. Recent studies have demonstrated that THH vessels are lymphatic in origin. The absence of Wilms tumor 1 antigen expression supports a malformative rather than neoplastic etiology. [4, 5]

One theory states that targetoid hemosiderotic hemangioma is the result of trauma to a preexisting hemangioma that subsequently is altered by thrombosis and recanalization; however, reports fail to document a preexisting vascular tumor, such as lobular capillary hemangioma or congenital vascular malformation, in the 100-plus cases reported to date. However, a 2015 case series by AbuHilal M et al reported three congenital pediatric cases or 3 (50%) of 6. [6]

A second theory suggests that trauma disrupts vasomotor enervation. This leads to an inability to regulate blood flow and results in progressive vascular ectasia, which is characteristic of targetoid hemosiderotic hemangioma. This scenario also has been postulated as a mechanism contributing to the development of acquired port-wine stains. No documented aberration in nerve fiber density in targetoid hemosiderotic hemangioma exists to support this theory.

A third theory proposes that trauma obstructs or destroys draining lymphatics or veins. This leads to proximal compensatory vasodilation and subsequent formation of a hemolymphangioma. This theory is supported by microscopic findings, such as fibrosis and inflammation (scar formation), extravasation of red blood cells and hemosiderin deposition (bruising), telangiectases (secondary to venous bed blockage or destruction), and lymphangiectases (consequence of destruction of lymphatic drainage). Expression of vascular endothelial cell growth factor receptor 3 (VEGFR-3) and D2-40, lymphatic endothelial cell markers, by targetoid hemosiderotic hemangioma endothelial cells confirms the primarily lymphatic origin of targetoid hemosiderotic hemangioma. [7]

These studies examining vessel origin have revealed microshunts between lymphatic channels and small blood vessels that may well explain many of the histologic features of targetoid hemosiderotic hemangioma, such as aneurysmatic microstructures (telangiectases/lymphangiectases) and erythrocytes within histologically apparent lymphatic spaces. The hemolymphatic nature of targetoid hemosiderotic hemangioma would also explain the clinicopathologic overlap with solitary angiokeratoma, an acquired vascular tumor that is also suspected to arise secondary to trauma and is characterized by superficial dermal dilated vessels (telangiectases).

No clear indication exists that targetoid hemosiderotic hemangioma is a true neoplastic process. Incomplete biopsies and complete excisions typically have not been followed by recurrence. To the contrary, reports of waxing and waning lesions suggest a reactive nature. In some cases, this may be the result of the hormonal influence on vasomotor stability that occurs during pregnancy and the menstrual cycle. [8, 9, 10, 11] Spontaneous resolution can be followed by recurrence and is not associated with any scarring. [5, 12, 13]



Trauma is the only known predisposing factor for targetoid hemosiderotic hemangioma (THH). [14, 15] Reports of targetoid hemosiderotic hemangioma secondary to irritation from a belt and arthropod assaults exist. Histologic findings of foreign body giant cell reaction in a few cases points to a preceding injury. Episodic changes of enlarging and diminishing hemorrhagic/hemosiderotic halo also implicate recurring trauma or vessel fragility.

Hormones can influence clinical morphology, resulting in the cyclic changes of waxing and waning diameter and peripheral color. Estrogen is believed to mediate pregnancy-related vessel changes, such as spider telangiectases, and estrogen is known to promote vascular permeability and fragility, venous distensibility, increased blood flow, and vasomotor instability. [16] In targetoid hemosiderotic hemangioma, fluctuating estrogen levels may result in vessel instability and leakage. Of note, hormonal receptors have not been identified histologically in lesions of targetoid hemosiderotic hemangioma noted to cyclically change with the menstrual cycle.




United States

Prevalence is unknown. Targetoid hemosiderotic hemangioma represents less than 0.1% of solitary pigmented lesions presenting to the Albany Medical College pigmented lesion clinic. From a dermatopathologic perspective, the Albany Medical College Dermatopathology service identified 33 cases out of more than 90,000 (0.1%) dermatopathologic accessions over a 3-year period.


Global incidence of targetoid hemosiderotic hemangioma is unknown but presumably is similar to that observed in the United States.


No known racial associations exist, although THH has been reported only in whites.


Males appear to be affected more frequently by targetoid hemosiderotic hemangioma than females (male-to-female ratio of 1.4:1). Episodically changing targetoid hemosiderotic hemangiomas have been described more frequently in females than in males.


In targetoid hemosiderotic hemangioma patient age varies from 5-72 years, and most patients present during their 20s and 30s.



With incisional biopsy or complete excision, the prognosis is excellent, as expected in association with a benign lesion. Reports in the literature clearly indicate that targetoid hemosiderotic hemangioma does not recur, does not invade locally or become locally destructive, and does not spread to other body sites

Rarely, spontaneous resolution can occur, but a risk for recurrence exists. [12, 13]


Patient Education

Because targetoid hemosiderotic hemangioma can mimic malignant skin tumors, advise patients who have had a targetoid hemosiderotic hemangioma to seek medicodermatologic consultation should they find another similar lesion on self-examination.