Pink nodule with a peculiar pattern on trichoscopy.

INTRODUCTION

A 35-year-old male presented with a swelling over scalp since 1 year. Initially, it was about a pea size, which gradually progressed to attain the present size. There was no history of preceding trauma to the site. He complained of bleeding from the lesion while combing. Examination revealed a single, sessile, erythematous nodule measuring 1 × 1 cm with lobulated surface located over parietal region of scalp [Figure 1]. Systemic examination and blood investigation were unremarkable.

Figure 1

Erythematous nodule with lobulated surface

Dermoscopic examination revealed homogeneous erythematous areas intercepted with yellowish white rail lines. Bright red line corresponding to vascular structures are also seen [Figure 2].

Figure 2

Dermoscopy shows homogeneous erythematous areas (yellow star) with white rail lines (black diamond) and vascular structures (black star)

Excision biopsy was performed and sent for histopathological study. The epidermis was flattened and dermis showed dilated and congested capillaries with edematous stroma [Figure 3].

Figure 3

Shows multiple, dilated and congested capillaries and edematous stroma (H and E, ×10) and close up view (H and E, ×40; inset)

WHAT IS YOUR DIAGNOSIS?

Answer

Pyogenic granuloma (PG) (Lobular capillary hemangioma).

DISCUSSION

The standard methods used to diagnose scalp and hair disorders like inspection, hair pull, or biopsy vary in sensitivity, reproducibility, and invasiveness. Dermoscopy of hair also called as trichoscopy, is a non invasive tool which helps us to observe surface and subsurface structures and provide novel diagnostic patterns. Various trichoscopy patterns have been studied, which help in diagnosis of hair disease and nontumoral scalp disorders.[1] However, there is paucity of trichoscopy studies in benign and malignant tumors of scalp.

PG is a common vascular proliferation of skin and mucous membranes affecting all age groups and more commonly men.[23] It presents as a solitary, rapidly growing, papule or polyp that bleeds easily after minor trauma.[456] It is very important to confirm the diagnosis by microscopy. Dermoscopy can aide in preoperative diagnosis of this benign tumor. Seven exclusive patterns were made up from the combination of the structures observed like ‘reddish homogeneous area’ (RHA) histologically corresponding to presence of numerous small capillaries or proliferating vessels, ‘white collarette’ (WC) corresponds to the hyperplastic adnexal epithelium that partially or totally embraces the lesion at the periphery, ‘white rail lines’ (WRL) correspond histologically to the fibrous septa that surround the capillary tufts and ‘vascular structures’ (VS). The pattern composed of RHA, WC, and WRL in the absence of VS has been demonstrated to be 100% specific for pyogenic granulomas in one study.[7] To conclude, PG is a benign tumor rarely affecting scalp and hence can be confused with various benign and malignant tumors of scalp and trichoscopy, although not a substitute for histology, can help in confirming the diagnosis.