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 Discussion
Mucinous carcinoma of the skin is a rare cutaneous neoplasm.[1-3] The
following are its main characteristics:
Main clinical features:[2,3]
- 800cated on the head.
- Slowly growing: described as dome shaped with a translucent hue or
subcutaneous mass.
- Recurs locally: metastases infrequent.[4]
- Treatment of choice: surgery. Moh's surgery has been effectively
used.[5,6]
- Must be distinguished from metastatic visceral mucinous carcinoma
(breast, colon, stomach, lung, ovary or pancreas). There
should be no evidence of primary tumor at these sites.
Main histopathological features:[2,3,7]
- Dermal pools of pale-staining sialomucin separated by thin fibrous septa.
Small cellular islands "float in the pools".
- Round or cuboidal cells, with a high nuclear:cytoplasmatic ratio. Some
of them have vacuolated cytoplasm forming ductal lumina.
- Inflamation or atypia nearly absent.
Our case shows some peculiarities. It is in an infrequent location (10f
mucinous carcinomas are in the inguinal region). It was associated with
multiple basal cell carcinomas and Bowen's disease, without clinical or
laboratory signs of arsenicism, nevoid basal cell carcinoma syndrome or
xeroderma pigmentosum. Another outstanding feature is the evolution over
thirty-five years, which speaks in favor of a benign prognosis. A trend
for local recurrence has been noted.
Histogenesis:[1]
The histogenenesis of mucinous carcinoma of the skin is debated. An apocrine
origin seems more likely. Various arguments that favor an apocrine or ecrine origin, are summarized:
Apocrine origin:[7]
- Decapitation secretion present in luminal cells, a typical feature of
apocrine secretion.
- Histologically indistinguishable from breast colloid carcinoma.
As the breast is considered to be a modified apocrine gland, breast
colloid carcinoma has an apocrine origin.
- Cells similar to neoplastic cells of pale-cell hidradenoma, a neoplasm
of apocrine origin.[8]
- Plasmocytoid cells float in the lakes of mucin, an alleged apocrine
feature.
- Positive staining for lactalbumin and gross cystic disease fluid
protein-15.[9]
Ecrine origin:
- Admixture of dark and light cells, like the secretory portion of the
ecrine coil.[10]
- Enzyme histochemistry similar to that found in ecrine secretory epithelium:
positive reactions with succinate dehydrogenase and phosphorylase.[10]
- Immunohistochemical reaction against anti-CEA as other ecrine tumors.[11]
Co-expression of cytokeratin and vimentin as fetal secretory cells of the
ecrine sweat glands.[12]
- Secretion similar to that of the dark, mucinous, cell of the ecrine coil
by electron microscopy.[10] The findings of extracellular mucin and
accumulation of it to form intercellular canaliculi have also been considered to
favor ecrine origin.[4]
References
1. Lennox B, Pearse AGE, Richards HGH. Mucin-secreting tumors of the skin:
with special reference to the so-called mixed-salivary tumour of the skin and
its relation to hidradenoma. J Pathol Bacteriol 1952; 64: 865-80.
2. Karimipour DJ, Johnson TM, Kang S, Wang TS, Lowe L. Mucinous carcinoma
of the skin. J Am Acad Dermatol 1996; 34: 323-6.
3. González-Vela MC, Mira Soto MC, Val-Bernal JF. [Mucinous carcinoma of
the scalp. Immunohistochemical study and review of the literature]. Actas
Dermosifiliogr. 1997; 88: 270-5.
4. Pilgrim JP, Wolfish PS, Kloss SG, Heng MCY. Primary mucinous carcinoma
of the skin with metastases to the lymph nodes. Am J Dermatopathol 1985; 7:
461-9.
5. Snow SN, Reizner GT. Mucinous eccrine carcinoma of the eyelid. Cancer
1992; 70: 2099-104.
6. Weber PJ, Hevia O, Gretzula JC, Rabinovitz HC. Primary mucinous
carcinoma. J Dermatol Surg Oncol 1998; 14: 170-2.
7. Requena L, Kiryu H, Ackerman AB. Ackerman´s Histopathologic diagnosis of
Neoplastic Skin Diseases. Neoplasms with Apocrine Differentiation.
Philadelphia: Lippincott-Raven Publishers, 1998: 907-47.
8. Santa Cruz DJ, Meyers J, Gnepp DR, Pérez B. Primary mucinous carcinoma
of the skin. Br J Dermatol 1978; 98: 645-53.
9. Carson HJ, Gattuso P, Raslan WF, Reddy V. Mucinous carcinoma of the
eyelid. An immunohistochemical study. Am J Dermatopathol 1995; 17: 494-8.
10. Headington JT. Primary mucinous carcinoma of the skin: histochemistry
and electron microscopy. Cancer 1977; 39:1055-63.
11. Fukamizu H, Tomita K, Inoue K, Takigawa M. Primary mucinous carcinoma of
the skin. J Dermatol Surg Oncol 1993; 19: 625-8.
12. Muramatsu T, Takagi K, Yashiki A, Sakurai S, Honoki K, Shirai T.
Mucinous carcinoma of the skin. Br J Dermatol 1995; 133: 820-1.
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