A 45-year-old woman presented with an asymptomatic pedunculated nodule on her scalp of 4 months' duration measuring approximately 1 cm in diameter (Figure). She did not relate the development of this nodule to trauma. At first, when the nodule developed it had been more friable and had oozed blood, according to the patient. The nodule was excised with a gradle scissor and sent for pathologic review, and the base was cauterized. The biopsy revealed dermal fibrosis and numerous capillaries and venules with plump endothelial cells arrayed in a radial fashion. The capillaries and venules were deployed along epidermis embedded in an edematous fibromyxoid stroma containing a mixed inflammatory infiltrate with rare neutrophils and no mast cells separating the lesion into lobules. The biopsy resulted in a diagnosis of pyogenic granuloma (PG). On follow-up 1 month later, the area had healed without scarring.
PG, also referred to as lobular capillary hemangioma, is a benign vascular proliferation (neoplasm).1–3 The name PG is a misnomer, as PGs represent proliferations of blood vessels and are not pyogenic/infectious entities nor macrophage-laden/granulomatous entities. PGs do not have the potential for malignant degeneration and can resolve on their own, given enough time.
PGs typically manifest as red nodules with smooth, glistening, erosive, ulcerative, or friable surfaces. Often, PGs are prone to bleeding or oozing serosanguinous fluid. This fluid discharge, discomfort, and pain are the sources of morbidity associated with PG. PGs are commonly accompanied by the so-called band aid sign—a Union Jack of adhesive bandages a patient places on top of a PG to absorb the fluid that can ooze out. The incidence of PGs is increased in pregnancy; in fact PGs are considered to be a dermatosis of pregnancy, and in this instance they alternatively carry the names granuloma of pregnancy, granuloma gravidarum, epulis gravidarum, pregnancy tumor, and pregnancy epuloids.4
Pyogenic granulomas are among the most common benign neoplasms. In one large series, PG accounted for 5 in 1000 of all skin nodules in children. Pyogenic granulomas associated with pregnancy occur in up to 5% of pregnancies. They evolve over weeks and can last months without treatment. Other red papules/nodules can mimic PG, and PGs can mimic other similar processes (Table I). Thus, while PGs can usually be diagnosed clinically, any hint that they are not typical should prompt biopsy and histologic examination (particularly because amelanotic melanoma can imitate PG).
|Reported Cases of Entities Initially Diagnosed as Entities Other Than PG That Turned Out to Be PG||Reported Cases of Entities Initially Diagnosed as PG or Which PG Was on Differential Diagnosis That Turned Out Not to Be||Other Entities to Consider in the Differential Diagnosis of PG|
|Proliferating pilomatricoma8||Acquired tufted angioma9||Nodular hidradenoma|
|Kaposi's sarcoma||Kaposi's sarcoma||Nodular hidradenocarcinoma|
|Bacillary angiomatosis||Bacillary angiomatosis||Angiolymphoid hyperplasia with eosinophilia|
|Malignant eccrine poroma||Malignant melanoma (in particular in children)|
|Eccrine poroma||Cutaneous lesions of metastatic visceral malignancy||Atypical fibroxanthoma|
|Granulation tissue||Pseudo-Kaposi's sarcoma (acroangiodermatitis)||Glomus tumor|
|Pseudo-Kaposi's sarcoma (acroangiodermatitis)||Recurrent intravascular papillary endothelial hyperplasia (Masson's lesion)||Cherry hemangioma|
|Basal cell carcinoma|
|Necrotic skin tag|
The cause of PG is unknown. While common wisdom attributes them to trauma, a large study by Patrice and colleagues5 of 178 pediatric patients found that only 7% had a history of trauma preceding the development of the PG. PGs can occur secondary to a variety of medications, medication procedures, and medical equipment placed on the skin or elsewhere in the body (Table II). PGs can occur in all ages, and a case of PG of the tongue in an 8-week-old child has been noted, but PGs are most common in prepubertal children with a mean age at onset of 6.7 years. After childhood, the incidence and prevalence of PG declines with a spike in incidence in women who are pregnant.
|Destructive First-Line||Destructive Second-Line||Medical Therapy||Injections||Surgical|
|Electrodesiccation and curettage7||Carbon dioxide laser||Topical imiquimod 5% cream||Injection of absolute ethanol||Ligation therapy|
|Cryotherapy8||Intense pulsed light system||Intralesional steroids||Surgical excision|
|Blunt or shave removal and silver nitrate cauterization||Pulse dye laser treatment||Intralesional steroids||Sclerotherapy with monoethanolamine oleate||Shave removal|
|Nd-YAG laser10||Systemic steroids|
|Oral erythromycin for 8 weeks||Sodium tetradecyl sulfate sclerotherapy|
Initially, PGs mimic granulation tissue (numerous capillaries and venules with plump endothelial cells deployed in a radial fashion along the epidermis amidst an edematous stroma containing a mixture of inflammatory cells without mast cells). Older PGs, as in the case presented, can be polypoid or nodular with a collarette of scale at their base. Regressing PGs manifest fibrosis. Metaplastic ossification in a cutaneous PG has been reported.
Forty-two percent of PGs in a series of 178 patients aged 17 years or younger occurred in the first 5 years of life; only 12% appeared in infants who were aged 1 year or younger.5 The male:female ratio was 3:2. Most patients (74.2%) noted no history of trauma or predisposing dermatologic condition. The mean PG size was 6.5 mm. The mean onset before presentation and diagnosis was 3.8 months. PGs most commonly were located in the head and neck area (62.4%), followed by trunk (19.7%), upper extremity (12.9%),and lower extremity (5.0%). The preponderance (88.2%) resided in the skin, and 11.8%involved the mucous membranes of the oral cavity and conjunctiva. Patterns of distribution of PG include satellitosis-type, disseminated, subcutaneous, and intravascular. PGs can occur throughout the gastrointestinal tract, the nasal mucosa, the larynx, and the conjunctiva and cornea.
PG can occur in association with nevi. Conjunctival blue nevus associated with PG has been noted. A Spitz nevus showing clinical features of both granuloma pyogenicum and pigmented nevus has also been reported. Finally, the development of PG satellite lesions has been noted after excision of a dermal melanocytic nevus on the back.
A variety of treatments exist for PGs (Table III). The 2 mainstays of treatment are destructive: cryotherapy and electrodesiccation and curettage. Clinical trials support the use of both of these therapies. One hundred thirty-five patients with PG were treated with cryotherapy using liquid nitrogen and followed up every 3 weeks until 3 months after disappearance of the lesion. Complete resolution of the PG occurred in all patients after a mean of 1.58 treatments (range, 1–4 treatments); 11.8% of patients were left with minor scars and 5.1% with hypopigmentation.6 Eighty-nine patients with PG were randomized for treatment with cryotherapy with liquid nitrogen or curettage and electrodesiccation.7 Forty patients in the cryotherapy group and 36 patients in the curettage group completed treatment that resulted in complete resolution of all PGs after 1–3 sessions (mean, 1.42) in the cryotherapy group and after 1 to 2 sessions (mean, 1.03) in the curettage group (P<.001). Twenty-three patients (57.5%) in the cryotherapy group and 25 patients (69%) in the curettage group had no scar or pigmentation abnormality. In a series of 178 patients, treatment in 149 with full-thickness skin excision and linear closure resulted in no recurrences, and treatment of 23 lesions by shave (intradermal) excision and cautery or cautery alone resulted in a recurrence rate of 43.5%.5
|Medications||Medical Infections/Conditions/Procedures||Topical Exposures/Devices|
|Reverse transcriptase inhibitors||Region of the burned skin||Hydroxyapatite orbital implant exposure|
|Gefitinib (nail)||Chronic actinomyces canaliculitis||Dermal regeneration dressing|
|Indinavir||Chronic Staphylococcus aureus infection (preventing socket reepithelialization after orbital exenteration)||Placement of the Medennium SmartPLUG punctum plug (Medennium, Irvine, CA)|
|Isotretinoin||Silicone punctal plugs|
|5-Fluorouracil||Circumcision||Exposed sternotomy wires|
|Capecitabine (a fluoropyrimidine)||Transconjunctival incisions||Orthodontic quadhelix appliance|
|Epidermal growth factor receptor inhibitors||Excision of a dermal melanocytic nevus on back||Silicone stent after canalicular injury|
|Mitoxantrone (associated with onycholysis associated with subungual abscesses, paronychia)||Treatment of verruca vulgaris with cryotherapy and salicylic acid gel 17%||Papaverine injection therapy for impotence|
|PG satellitosis after carbon dioxide laser|
|Mitomycin C eye drops (PG in anophthalmic socket)||PG arising in port-wine stain after cryotherapy|
|PG arising after cryosurgery for venous lake|
|Oral contraceptives||Strabismus surgery|
For small PGs, for which the diagnosis is not in doubt, the author favors cryotherapy as initial therapy, because it is easier to administer and does not require the injection of lidocaine. For PGs greater than 6 mm or that have persisted despite 1 or 2 rounds of cryotherapy, the author performs a shave removal, sends the specimen for pathologic examination, and burns and scrapes the base.