Pyogenic granulomas (PGs), usually solitary and isolated, have rarely been reported to arise as lesions within preexisting vascular malformations.1 Multiple, distinct, PG-like lesions within capillary or arteriovenous malformations (AVMs) have been described.2 To our knowledge, no cases of solitary or agminated PG-type growths have been reported in congenital hemangiomas (CHs).
A healthy male infant presented with a congenital, unchanged, asymptomatic, 2.5-cm, indurated, violaceous plaque with a surrounding blue to white halo on the right jawline (Figure 1A). No other hemangiomas were present. Ultrasonography showed a lobulated vascular mass with prominent flow, consistent with CH.
A, Violaceous plaque on the right jawline at first presentation. B, Patient presented 3 months later with bleeding and new growth associated with pain at the superior pole of the lesion. C, Recurrence of grouped erythematous nodules was apparent 10 days after partial excision of the lesion.
Findings of a subsequent complete blood cell count were normal. Three months later, the patient returned with bleeding and friable granulation tissue–like changes within the hemangioma (Figure 1B). Agminated PG overlying the preexisting CH was suspected. The superficial friable tissue and a portion of the primary lesion were excised.
Ten days after excision, there was partial regrowth of the lesion. Examination revealed an overlying 1.0-cm area of coalescing, erythematous, and friable papules, consistent with recurrent agminated PG (Figure 1C). This was then reexcised in its entirety.
Microscopic evaluation showed a lobular proliferation of capillaries in the superficial dermis and a capillary proliferation in the deep dermis and subcutaneous tissue with intervening dermal fibrosis with sparse entrapped capillaries (Figure 2A-C). Endothelial cells were immunoreactive for CD31 and CD34. Staining with Ki-67 demonstrated differentially increased activity in the superficial (ie, PG-like) portion vs the deeper (ie, CH) portion (Figure 2D and E), even when the intermixture of inflammatory cells within the superficial portion was accounted for. Stainings with GLUT-1, VVG, WT1, and OCT4 proved negative throughout the lesion. Smooth-muscle actin demonstrated precapillary sphincters throughout the superficial and deep portions. The patient, 1 year later, remained free from recurrence.
Hematoxylin-eosin (A-C) and Ki-67–stained (D and E) specimens. A and B, Pyogenic granuloma (A) overlying a deep capillary congenital hemangioma proliferation (B) with intervening stroma containing fibrosis with entrapped capillaries (original magnifications ×40). C, Superficial lobular capillary proliferation with a collarette of scale, with dermal fibrosis and entrapped capillaries; a deeper collection of capillaries is seen in the deep dermis and subcutaneous tissue (original magnification ×4). D and E, Staining with Ki-67 demonstrated an increased mitotic index in the superficial component (D) compared with the deep one (E) (original magnifications ×40 [D] and ×20 [E]).
Agminated PGs arising in association with a preexisting vascular lesion have been reported in 5 previous cases. Two adults developed agminated PGs with underlying AVMs.3 Three children developed agminated PGs within preexisting macular congenital vascular malformations believed to represent AVMs.4
Recently, the microscopic presence of areas of microvascular proliferation (similar to that of PGs) has been described in a subset of excised symptomatic or changing venous malformations and AVMs. Similar to the present case, these areas of microvascular proliferation demonstrated high levels of Ki-67 labeling.5 Of the vascular lesions in which microscopic evidence of microvascular proliferation was present, 90% were AVMs.5
Microvascular proliferation and PGs may occur commonly in AVMs owing to the high-flow properties of AVMs and subsequent biomechanical effects on angiogenesis, which may activate the FLT4 and nitric oxide pathway, a proposed mechanism of angiogenic growth in the development of PG-like lesions.5,6 Both CHs and infantile hemangiomas (IHs) are also high-flow vascular tumors, but despite the common occurrence of IHs, PGs have not been reported to occur in association, possibly owing to the inherent properties of IHs to gradually involute with time.
Given our observation of dermal fibrosis and entrapped capillaries in the tissue between the deeper CH and the superficial PG-like proliferation, this may have represented a single neoplasm. Specifically, the deep capillary proliferation may have tracked up to the superficial dermis, perhaps due to angiogenesis growth factor release in the local microenvironment or in response to minor trauma. The differential Ki-67 labeling does not necessarily indicate that the 2 processes are entirely distinct.
In conclusion, we present the novel observation of agminated PG arising in association with a CH. Recognition of this type of proliferative vascular growth within noninvoluting, high-flow anomalies may prompt earlier treatment. Further study may provide clues regarding the pathogenesis and treatment of high-flow vascular growths and of proliferative lesions arising in this context.
Corresponding Author: Megha Tollefson, MD, Department of Dermatology, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (Tollefson.firstname.lastname@example.org).
Published Online: March 19, 2014. doi:10.1001/jamadermatol.2013.7530.
Conflict of Interest Disclosures: None reported.
Funding/Support: This study was supported financially by the Department of Dermatology at Mayo Clinic.
Role of the Sponsors: The Department of Dermatology at Mayo Clinic had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Barrick B, Lehman J, Tollefson M. Agminated Pyogenic Granuloma–Like Growth Arising in a Congenital Hemangioma. JAMA Dermatol. 2014;150(7):781-783. doi:10.1001/jamadermatol.2013.7530