Pedunculated and telangiectatic merkel cell carcinoma: an unusual clinical presentation.

Merkel cell carcinoma (MCC) is an uncommon aggressive neuroendocrine tumor of the skin that classically presents on chronic sun-damaged skin as a skin-colored, red or violaceous, firm and nontender papule or nodule with a smooth and shiny surface. Ulcerations can be observed very seldom and only in very advanced lesions. We present a unique case of a MCC presenting with two unusual clinical features: The Telangiectatic surface and the pedunculated aspect.

What was known?

1. Merkel cell carcinoma (MCC) is an uncommon malignant neuroendocrine tumor of the skin that typically presents as a skin-colored, red or violaceous, firm and nontender papule or nodule with a smooth and shiny surface.

2. MCC may rarely present as a chalazion-like lesion, a conjunctival multinodular mass, a tumor masquerading as granulation tissue, a subcutaneous mass, a small crusted erosion or a plaque-like lesion.

3. A recent study has suggested that the presence of three or more of several clinical features summarized in the acronym “AEIOU” (asymptomatic/lack of tenderness, expanding rapidly, immune suppression, older than 50 years, and ultraviolet-exposed site on a person with fair skin) may help to suspect an MCC.

Introduction

Merkel cell carcinoma (MCC) is a rare aggressive neuroendocrine tumor of the skin that classically develops rapidly over weeks to months on chronic sun-damaged skin as a skin-colored, red or violaceous, firm and nontender papule or nodule with a smooth and shiny surface.[12] Ulcerations can be observed very seldom and only in very advanced lesions.[1] The most common sites of origin of the tumor are the head, neck, lower limbs and upper extremities.[3] MCC may rarely present with atypical clinical aspects. In particular, have been described cases of palpebral MCCs mimicking a chalazion,[45] one case of periocular MCC presenting as a conjunctival multinodular mass,[6] one case of MCC masquerading as granulation tissue on a teenager's toe,[7] a case of MCC arising from the subcutaneous fat and presenting as an entirely subcutaneous lesion with intact skin,[8] one case of MCC presenting as a 2-mm crusted erosion on the nose[9] and several case of MCC presenting as plaque-like lesions, especially on the trunk.[1] In this report we describe the first case of MCC characterized by a pedunculated aspect and a Telangiectatic surface.

Case Report

A 70-year-old woman was referred to our department for evaluation of an asymptomatic skin neoformation on the right side of the neck. The lesion appeared about two months earlier and since then it increased rapidly in size. Physical examination revealed a reddish, firm-elastic, pedunculated lesion with a translucent and telangiectasic surface. The larger diameter of the tumor was 18 mm, while the stalk diameter was 12 mm [Figures 1 and 2]. No other significant skin or mucosal lesions were seen and no lymphadenopathy was present. The nodule was excised and submitted to histological examination, which showed uniform round cells with scant cytoplasm in the dermis [Figure 3]. Immunostaining with cytokeratin 20 highlighted a perinuclear dot-like positivity of cells [Figure 4a]. Furthermore, the cells were chromogranin A, synaptophysin, somatostatin and CD56 positive [Figure 4b]. On the basis of the clinical, histological and immunochemical data, we made a diagnosis of MCC. Sonography of locoregional lymph nodes and abdomen as well as a chest X-ray were negative. In accordance with the current guidelines,[1] a wide excision of the residual surgical scar was performed with margins of 2 cm and the consequent surgical defect was reconstructed with a skin graft taken from anterior surface of the right thigh. Subsequently, sentinel lymph node biopsy was executed, with a negative result. Considering that the tumor presented with only skin involvement, we decided not to perform any further treatment. During a 6-month follow-up, no local or distant recurrence was reported. Anyhow, considering the high rate of recurrence of MCC,[1] we recommended to the patient to continue a constant follow up.

Figure 1

Reddish, translucent and pedunculated nodule with Telangiectatic surface on the right side of the neck

Figure 2

Magnification of the nodule. The tumor has an attachment to the skin surface which is smaller (12 mm in diameter) than the greatest diameter of the lesion (18 mm)

Figure 3

Dermal infiltrate of uniform round cells with scant cytoplasm (H and E, Magnification ×200)

Figure 4

(a) The cells show positive staining with “dot-like pattern” to cytokeratin 20 (Magnification ×100), (b) Positive staining for CD56 (Magnification ×100)

Discussion

The case of MCC reported here represents a very atypical presentation of this rare tumor due to the simultaneous presence of two unusual clinical features: The telangiectasic surface and the pedunculated aspect. The telangiectasic appearance is a very rare feature and it is not included in the classical clinical characteristics of MCC,[23] while, to the best of our knowledge, the pedunculated presentation has never been described in literature. Therefore, our case is the first example of pedunculated MCC. This variant of MCC, as each pedunculated neoformation, is characterized by the fact that it has an attachment to the skin surface which is smaller than the greatest diameter of the lesion. In other words, the lesion is attached by a stalk. The existence of a previously unknown pedunculated variant of MCC underlines the importance to suspect, among other hypothesis, a possible MCC in subjects presenting with an asymptomatic pedunculated skin neoformation. The clinical differential diagnosis includes acrochordon, polypoid basal cell carcinoma, fibroepithelioma of Pinkus and intradermal melanocytic nevus. A recent study has suggested that the presence of three or more of several clinical features summarized in the acronym “AEIOU” (asymptomatic/lack of tenderness, expanding rapidly, immune suppression, older than 50 years, and ultraviolet-exposed site on a person with fair skin) may indicate a concerning process that would warrant a biopsy to research a MCC. Our case is in agreement with this study because four of these features were present in the clinical description (asymptomatic neoformation characterized by a very rapid growth and occurred on a UV-exposed site in patient older than 50 years). For this reason, we believe that the use of acronym “AEIOU” could also serve as a good support to suspect the pedunculated variant of MCC. Anyhow, further reports of pedunculated MCC are necessary to confirm this point and to clarify the meaning of the Telangiectatic aspect reported in our case. In fact, the low number of cases does not allow to understand if this feature is a specific characteristic of this variant of MCC or not.

What is new?

1. This report describes the first case of pedunculated MCC, thus adding a new clinical presentation for this rare tumor.

2. The existence of this new variant of MCC underlines the importance to suspect, among other hypothesis, a possible MCC in subjects presenting with an asymptomatic pedunculated skin neoformation.

3. On the basis of the clinical features present in this case, we believe that the use of acronym “AEIOU” could serve as a good support also to suspect the pedunculated variant of MCC.