Nodular Mucinosis of the Breast: Expanding Our Understanding With an Unusual Case

Abstract

Nodular mucinosis of the breast is an extraordinarily rare lesion that occurs in patients who do not have Carney syndrome. Typically, the affected patients are young women with no medical history and a nodule under 1 nipple. Histopathologic examination has, until now, shown a multinodular myxoid lesion containing scattered capillaries and histiocytes but void of epithelial components. We present the case of a 72-year-old woman with a history of mucinous carcinoma of the breast who now presents with a painful subareolar nodule of the same breast. Biopsy and histological examination confirmed nodular mucinosis of the breast.

Papular mucinosis of the breast after radiation therapy

“…Our case should also be distinguished from nodular mucinosis of the breast, which commonly presents as an idiopathic uni‐nodular or multi‐nodular eruption on the breast, unrelated to Carney complex, mostly under one of the nipples, especially in young women . The lesions are nodules and typically over 1 cm in diameter . Also, histopathologic study of such cases reveals features different from those evidenced in papular mucinosis, with more prominent dermal mucin deposits organized in non‐encapsulated but well‐demarked nodules with scattered capillaries inside .…”

“…Our case should also be distinguished from nodular mucinosis of the breast, which commonly presents as an idiopathic uni‐nodular or multi‐nodular eruption on the breast, unrelated to Carney complex, mostly under one of the nipples, especially in young women . The lesions are nodules and typically over 1 cm in diameter .…”

A Rare Case of Nodular Mucinosis of the Breast

“…The cut surface demonstrates a well-circumscribed but not encapsulated, multinodular lesion that is grayish-white, grayish-pink, or yellow-to-tan in color [2-6] and has a myxoid, mucinous or gelatinous consistency [3-6]. The histological features of nodular mucinosis of the breast include a multinodular myxoid or mucinous lesion separated by fibrocollagenous stroma [2-6].…”

“…The lesion consists of sparse spindle cells, which have bland and elongated nuclei, scant and/or pale cytoplasm, and indistinct cell boarders [2,4,5]. Rarely histiocytes, lymphocytes, plasma cells, and/or mast cells can be seen within and around the nodules [2-6], and some capillaries or small vessels are seen within the lesions [3,5,6]. The lesion neither contains nor invades the breast parenchyma [2-4,6].…”

Nodular Mucinosis of Breast: A Case Report

“…It is distinct from myxomas developed in Carney complex. There are 13 reported cases in the English literature [1][2][3][4][5][6][7][8][9]. All the reported cases involve around the nipple of young women, as well as men.…”