Granuloma Annulare – A Manifestation of Primary Cutaneous Mucinous Carcinoma?

Abstract

The objective of this report is to present a rare case of primary cutaneous mucinous carcinoma (PCMC) manifesting with granuloma annulare (GA), and to discuss the association as a paraneoplastic phenomenon.A 65-year-old female presented with a painless, slow-growing, cystic nodule less than 1 cm over the left lateral canthus. The clinical presentation was highly suspicious of sebaceous cyst.The histopathologic examination revealed variable sizes of neoplastic cell clusters in a pool of abundant mucin. A focus of palisading lympho-histiocytic infiltrate surrounding a necrobiosis suggestive of granuloma annulare adjacent to the tumor is identified. Series of extensive investigations performed did not reveal any primary origin.GA can rarely be associated with various malignant conditions. Its association and prognostic importance to these conditions are unclear. The presence with certain malignancies and the resolution of GA with the treatment of underlying malignancy are an indicator that this condition can very well be a paraneoplastic phenomenon.

Primary Cutaneous Mucinous Carcinoma: A Review of the Literature

“…In many cases, lesions are initially biopsied or excised under the assumption of it being a benign epidermal inclusion cyst. 22,23 The clinical differential diagnosis may include a number of other benign neoplasms such as a hidrocystoma, neuroma, hemangioma, or lipoma, as well as many malignant neoplasms such as basal cell carcinoma, squamous cell carcinoma, sebaceous carcinoma, and metastatic adenocarcinoma, including metastatic mucinous carcinoma from the breast, gastrointestinal (GI) tract, lung, and ovary, among others. 11,15,24 Given the rarity of PCMC compared with mucinous carcinoma of other organs, it is imperative to rule out metastatic disease from one of these extracutaneous sites for proper diagnosis and to inform prognosis and treatment.…”