Extragingival pyogenic granuloma histologically mimicking capillary hemangioma.

Pyogenic granuloma is a tumor-like proliferation to a non-specific infection. The tumor-like growth is considered to be non-neoplastic in nature and presents in various clinical and histological forms in the oral cavity. Hemangiomas are benign vascular anomalies characterized by benign proliferation of blood vessels. The aim of this article is to drive attention toward the uncommon location of capillary hemangioma on the palate. In spite of their benign nature, intraoral capillary hemangiomas are always clinically important to be diagnosed well in time and suitably managed. The lesion in the present case although clinically diagnosed as pyogenic granuloma gave a histological picture of capillary hemangioma when surgically excised.

INTRODUCTION

Pyogenic granuloma and capillary hemangioma are well-known and commonly occurring benign vascular lesions of the oral cavity. Pyogenic granuloma is a relatively common, soft-tissue tumor of the oral cavity that is believed to be reactive and not neoplastic in nature. The name pyogenic granuloma is a misnomer since the condition is not associated with pus and does not represent a granuloma histologically.[1] Some authors use the term lobular capillary hemangioma (LCH) for this lesion.[2]

Hemangiomas are benign tumors composed of blood vessels and are classified based on their histological appearance as capillary, mixed cavernous, or a sclerosing variety that tends to undergo fibrosis.[3] It is the most common benign oral soft-tissue tumor in children. Although, it is considered one of the common soft-tissue tumors of the head and neck, it is relatively rare in the oral cavity. Capillary hemangiomas are composed of many small capillaries lined with a single layer of endothelial cells supported in connective tissue stroma of varying density.[4] Both pyogenic granuloma and capillary hemangioma rarely occur on the palatal mucosa, occur in younger age group and histopathologically resemble each other.

Thus, the differentiation between a capillary hemangioma and pyogenic granuloma has to be made which sometimes becomes difficult. The aim of this report is to present a case of a lesion which was clinically diagnosed as pyogenic granuloma, but histologically resembled capillary hemangioma.

CASE REPORT

The present case is about a 21-year-old female patient reported to the Department of Periodontics with the chief complaint of a swelling on her hard palate.

The lesion had grown rapidly to the present size over duration of 2 weeks. The growth was asymptomatic except for the uneasiness which the patient mentioned. The patient's medical history was non-contributory and she did not give any history of intake of any medications.

Clinical examination revealed a solitary, exophytic, pedunculated, spherical-shaped, reddish pink swelling with distinct borders and irregular surface [Figure 1]. Adjacent palatal mucosa was normal. Swelling was located in the anterior part of the hard palate just posterior to the central incisors measuring 1.5 cm × 1.5 cm in size. On palpation, the swelling was non-tender, soft to firm in consistency, and blanched on pressure.

Figure 1

Clinical view of the lesion

Occlusal and intra oral periapical radiograph showed no loss of bone in relation to the lesion [Figures 2 and 3]. Based on the clinical signs and symptoms, a provisional diagnosis of pyogenic granuloma was established and capillary hemangioma was kept as differential diagnosis. The treatment was planned under local anesthesia with all necessary emergency equipment's at hand under the guidance of a trained anesthetist, keeping in mind the differential diagnosis of capillary hemangioma.

Figure 2

Occlusal radiographic view of the involved site

Figure 3

Periapical radiograph of the involved site

The lesion was excised in toto using electrosurgery. Periodontal dressing was placed on the operated area, and the patient was given post-operative instructions. After 1 week, the dressing was removed. The healing was uneventful [Figure 4].

Figure 4

Clinical view 2 weeks after surgery

The excised tissue was fixed in 10% neutral buffered formalin and was sent for routine hematoxylin and eosin (H and E) staining. The histopathological section of the specimen stained with H and E showed a polypoidal structure lined by stratified squamous epithelium with focal areas of ulceration. There were underlying numerous vascular channels lined by endothelial cells admixed with varying number of inflammatory cells. Focal areas of hemorrhage were also evident [Figures 5 and 6]. The connective tissue revealed numerous blood capillaries of varying caliber with plump and proliferating endothelial cells. The endothelial cells depicted varying degrees of atypia. The overall features were suggestive of capillary hemangioma.

Figure 5

Histological appearance of the lesion (H and E, ×10)

Figure 6

Histological appearance of the lesion (H and E, ×20)

DISCUSSION

In the oral cavity pyogenic granulomas show a striking predilection for the gingiva with interdental papillae being the most common site in 70% of cases. It is of two types based on histological features. These are LCH type and non-LCH type. LCH pyogenic granuloma is characterized by proliferating blood vessels that are organized in lobular aggregates even though superficially the lesion shows no specific change of edema, capillary dilation or inflammatory granulation tissue reaction. The non-LCH pyogenic granuloma shows vascular proliferation that resembles granulation tissue. The foci of fibrous maturation were seen in 15% of non-LCH pyogenic granuloma but were totally absent in LCH type of pyogenic granuloma.[5] A history of trauma to the area is rarely elicited from the patients. Usually, the patient is an older infant or young child, although the lesions also occur in adults. It usually occurs on the lips, oral mucosa, tongue, and nasal cavity. An interesting and not uncommon finding is the occurrence of pyogenic granuloma within a port-wine vascular birthmark, either intraorally or extraorally.

Hemangiomas are common benign tumors of the head and neck region but their occurrence on the palatal mucosa is extremely rare.[6] In 80% of cases, hemangiomas occur as single lesions. Capillary hemangiomas have a 3:1 female-to-male ratio.[7] Clinical development of such lesions is slow, asymptomatic and painless, but it may also grow rapidly. The case reported here was painless, asymptomatic but had grown rapidly to reach the present size. Thus, the differentiation between a pyogenic granuloma and hemangioma is done histologically, which otherwise becomes difficult. Histologically, LCH pyogenic granuloma has an attenuated endothelial lining surrounded by somewhat uniform proliferation of plump to spindled cells, in contrast to the more prominent endothelial cells and an array of capillary size blood vessels with lobular architecture of a capillary hemangioma. Moreover, the capillaries in LCH pyogenic granuloma are frequently arranged perpendicular to the surface.

Hemangiomas may easily be confused with other type of lesions like vascular malformations. Vascular malformations are present at birth, whereas hemangiomas develop later in life.[4] The hallmark of vascular malformations is proportionate growth throughout the life of an individual.[7]

Vascular malformations are localized or diffuse errors of embryonic development. They are also classified as capillary, lymphatic, venous, arterial or a combination of these depending on the clinical and histological appearance of abnormal channels.[8] Other intraoral enlargements from which the lesion has to be differentially diagnosed are peripheral giant cell granuloma, peripheral ossifying granuloma, squamous cell granuloma, Kaposi's sarcoma, epulis, metastatic cancer.[9]

All clinically suspected pyogenic granulomas and capillary hemangiomas need to be biopsied to rule out more serious conditions as mentioned previously. Although conventional surgical excision is the treatment of choice for smaller lesions, recently other treatment options have been described such as electrosurgery, Nd: YAG laser, CO2 laser, cryosurgery. The present case was operated by electrosurgery because of its efficacy, minimum intraoperative bleeding and cost effectiveness. Keeping in mind, capillary hemangioma as one of the differential diagnosis, appropriate hemostatic measures were kept at hand before starting the procedure. Larger lesions like central hemangiomas of the jaw bone or intraosseous hemangiomas need to be treated by other means of therapy like sclerosing agents and embolization.[10] Other treatment protocols include the use of steroids, radiation and compression depending on the clinical features and site of involvement. Although, there is limited evidence in the literature to support the use of electrocautery in the treatment of pyogenic granuloma/oral capillary hemangioma. The present case responded well to the treatment, and was kept on maintenance visits for 6 months. No recurrence was reported.

CONCLUSION

Capillary hemangioma is a lesion that is diagnosed primarily on histological findings. Although, it is asymptomatic, its peculiar location may require immediate intervention. The case in the discussion was worthy of importance because of its uncommon location on the anterior palate. Lesions in this area often lead to impaired nutrition and oral hygiene, increased accumulation of plaque and microorganisms and thereby increased susceptibility to oral infections. The clinical picture and location of the lesion led to a provisional diagnosis of pyogenic granuloma, but histological findings were suggestive of capillary hemangioma. Early detection and biopsy of such lesions is necessary to institute appropriate management. In addition, the surgical management should be performed with caution because the tissues may bleed profusely intra-operatively and post-operatively.