Mucinous breast carcinoma. Single cutaneous metastasis

Papular mucinosis of the breast after radiation therapy

Localized papular mucinosis is a type of mucinosis induced by several different causes. However, to the best of our knowledge, prior radiation therapy has not been reported to be related to papular mucinosis. We present a case of a 47-year-old woman who had undergone an operation for a breast carcinoma 2 years earlier and received local radiotherapy in the affected breast. Currently, she presents multiple erythematous papules that are caused by abundant dermal mucin deposits. We discuss some potential differential diagnoses.

Skin metastasis: a pathologist's perspective

Skin metastasis is defined as the spread of malignant cells from a primary malignancy to the skin. It is one manifestation of systemic spread of cancer. The tumor cells originate either from an internal malignancy or from a primary skin cancer. This study presents a literature review concerning these issues as well as this author's experience encountered throughout 19 years of surgical pathology and dermatopathology practice. Several conclusions are evident. Generally, skin metastases are encountered in 0.7-9% of all patients with cancer and as such the skin is an uncommon site of metastatic disease when compared to other organs. There is usually a long-time lag between the diagnosis of the primary malignancy and the recognition of the skin metastases. However, these metastases may be the first indication of the clinically silent visceral malignancies. The regional distribution of the skin metastasis, although not always predictable, is related to the location of the primary malignancy and the mechanism of metastatic spread. The relative frequency of skin metastasis correlates with the type of primary cancer, which occurs in each sex. For instance, lung and breast carcinomas are the most common primaries that send skin metastasis in men and women, respectively. The head and neck region and the anterior chest are the areas of greatest predilection in men. The anterior chest wall and the abdomen are the most commonly involved sites in women. Skin metastases usually appear as non-specific groups of discrete firm painless nodules that emerge rapidly without any explanation. They vary in size from so tiny as to be of 'miliary lesions' to as large as 'Hen's egg size'. Some skin metastasis may mimic specific dermatological conditions such as cutaneous cyst, dermatofibroma, pyogenic granuloma, hemangioma, papular eruptions, herpes zoster eruptions, rapidly infiltrating plaques, alopecic patches, cellulitis and erysipelas. Histologically, the skin metastases usually show features reminiscent of the primary malignancy, but with variable degrees of differentiation. Molecularly, skin metastasis is an organized, non-random and organ-selective process orchestrated by interaction among several heterogeneous molecules, which are largely unknown. Metastasis to the skin is often a pre-terminal event that heralds poor outcome.

Mucinous Carcinoma of the Skin, Primary, and Secondary

We present the largest series of mucinous carcinoma involving the skin, describing the histopathologic, immunohistochemical, electron microscopic, and cytogenetic findings. Our aim was fully to characterize the clinicopathologic spectrum and compare it with that seen in the breast. In addition, we wished to reevaluate the differential diagnostic criteria for distinguishing primary mucinous carcinomas from histologically similar neoplasms involving the skin secondarily, and study some aspects of their pathogenesis. We demonstrate that primary cutaneous mucinous carcinomas span a morphologic spectrum compatible to their mammary counterparts. Both pure and mixed types can be delineated morphologically, and some lesions have mucocele-like configurations. Most lesions seem to originate from in situ lesions that may represent, using mammary pathology terminology, ductal hyperplasia, atypical ductal hyperplasia, or ductal carcinoma in situ or a combination of the three. Inverse cell polarity appears to facilitate the progression of the changes similar to lesions in the breast. The presence of an in situ component defines the neoplasm as primary cutaneous, but its absence does not exclude the diagnosis; although for such neoplasms, full clinical assessment is essential. Mammary mucinous carcinoma involving the skin: all patients presented with lesions on chest wall, breast, axilla, and these locations can serve as clue to the breast origin. Microscopically, cutaneous lesions were of both pure and mixed type, and this correlated with the primary in the breast. Dirty necrosis was a constant histologic finding in intestine mucinous carcinomas involving the skin, and this feature may serve as a clue to an intestinal origin.

Secondary mucinous carcinoma of the skin: metastatic breast cancer

BACKGROUND

Breast cancer is the most common cancer in women. Its involvement of skin is the most frequent of visceral cancers in women. In cutaneous metastatic disease, including breast cancer, the clinical and histologic pattern may be specific or nonspecific. Specific clinical patterns of cutaneous metastatic disease are linked with breast cancer but occur less often with other cancers metastatic to skin. Likewise, specific histologic patterns of cutaneous metastatic disease are linked with breast cancer but occur less often with other cancers metastatic to skin.

OBJECTIVE

To present a case of a mucinous breast cancer metastatic to skin where the histologic pattern is similar to the primary tumor.

METHODS

This is a case report and a literature review.

RESULTS

Metastatic breast cancer may rarely resemble primary skin cancer, in this case primary mucinous carcinoma of the skin. We describe a 60-year-old woman with breast cancer with the incidental finding of a nonspecific, soft, solitary nodule on her back. It was found to contain mucinous material and on close examination was found to be a metastatic mucinous carcinoma of the skin from a primary adenocarcinoma of the breast.

CONCLUSION

One usually considers that hard, firm nodules are more suggestive of cutaneous metastatic disease than soft, nondescript ones, but one should be careful to consider secondary mucinous carcinoma of the skin and a histologically similar solitary cutaneous metastasis.

Primary mucinous carcinomas of the skin express TFF1, TFF3, estrogen receptor, and progesterone receptors

Mucinous carcinoma may present at various sites, including the breast and the gastrointestinal tract. Rarely, such tumors arise within the skin. Comparatively, breast lesions are relatively common and usually associated with a good prognosis. When pure, they are typically estrogen (ER) and progesterone receptor (PR) positive and responsive to tamoxifen. The authors studied 12 mucinous carcinomas of the skin and compared the morphology with that of typical mammary lesions. The authors also evaluated for expression of estrogen receptor, progesterone receptor, and the mucus-associated peptides of the trefoil factor family (TFF), TFF1 (formerly pS2) and TFF2 (formerly SP), using immunohistochemistry. The localization of mRNAs for TFF1, TFF2, and TFF3 (formally ITF) was also studied in a subset of three tumors, using in-situ hybridization with S35 labeled riboprobes. The Grimelius stain was used to look for evidence of neuroendocrine differentiation. Eight resembled type A mucinous carcinomas of the breast, two resembled type B, and one had composite features. The 12th was a papillary neoplasm. The two type B tumors exhibited argyrophilia. All showed strong nuclear staining with the estrogen receptor antibody but a more varied pattern with antibodies to progesterone receptor and TFF1. None labeled for TFF2. The detection of TFF1 in mammalian skin is a novel finding. Cutaneous mucinous carcinoma shows strong similarities to its mammary counterpart, including expression of estrogen receptor, TFF1, and TFF3 mRNA. These observations suggest that some mucinous carcinomas of the skin might respond to antiestrogenic therapies.

Histopathologic aspects of cutaneous metastatic disease

In cutaneous metastatic disease the histologic pattern may be specific or nonspecific. Carcinoma cutis most often shows only the nonspecific pattern of an adenocarcinoma, a squamous cell carcinoma, or an undifferentiated metastatic tumor. However, certain clinical and histologic characteristics may suggest a primary tumor site and type. In addition, special histologic stains and the use of immunohistochemical and electronmicroscopic techniques may also prove valuable in the diagnosis of carcinoma cutis and other cutaneous metastatic diseases.