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Information from PDQ -- for Health Professionals
Merkel cell carcinoma
208/10847
** GENERAL INFORMATION **
Merkel cell carcinoma (MCC), or neuroendocrine carcinoma of the skin, is an
uncommon and often aggressive malignancy that has a poor prognosis. The Merkel
cell is located in or near the basal layer of the epidermis and is closely
associated with terminal axons.[1-3] MCC is predominantly a tumor of the
elderly, and most reported cases have occurred in Caucasians.[1,2,4-6] It
occurs most frequently in the head and neck region and in the extremities, and
has a predilection for the periocular region.[1,2,5,6] While MCC may be
difficult to diagnose, it usually presents as a painless, indurated, solitary
dermal nodule with a slightly erythematous to deeply violaceous color. MCC
frequently involves regional lymph nodes (10%-45% at initial
presentation),[1,2,4,5,7] and between 50% and 75% of patients will develop
regional lymph node metastases at some time during the course of their
disease.[1,2,4] Distant metastases eventually occur in up to one half of
patients, with lymph nodes, the liver, bone, brain, lung, and skin as the most
common sites of distant involvement.[1,2,5,6,8] MCC can often develop an
aggressive course, similar to aggressive melanoma. After excision of the
primary tumor, local recurrence develops in 25% to 44% of patients, and is
often associated with inadequate surgical margins.[1,4,5]
References:
1. Haag ML, Glass LF, Fenske NA: Merkel cell carcinoma. Diagnosis and
treatment. Dermatologic Surgery 21(8): 669-683, 1995.
2. Ratner D, Nelson BR, Brown MD, et al.: Merkel cell carcinoma. Journal of
the American Academy of Dermatology 29(2 part 1): 143-156, 1993.
3. Gould VE, Moll R, Moll I, et al.: Neuroendocrine (Merkel) cells of the
skin: hyperplasias, dysplasias, and neoplasms. Laboratory Investigation
52(4): 334-353, 1985.
4. Yiengpruksawan A, Coit DG, Thaler HT, et al.: Merkel cell carcinoma.
Prognosis and management. Archives of Surgery 126(12): 1514-1519, 1991.
5. Goepfert H, Remmler D, Silva E, et al.: Merkel cell carcinoma (endocrine
carcinoma of the skin) of the head and neck. Archives of
Otolaryngology, Head and Neck Surgery 110(11): 707-712, 1984.
6. Gollard R, Weber R, Kosty MP, et al.: Merkel cell carcinoma. Review of
22 cases with surgical, pathologic, and therapeutic considerations.
Cancer 88(8): 1842-1851, 2000.
7. Tai PT, Yu E, Winquist E, et al.: Chemotherapy in neuroendocrine/Merkel
cell carcinoma of the skin: case series and review of 204 cases.
Journal of Clinical Oncology 18(12): 2493-2499, 2000.
8. Marks ME, Kim RY, Salter MM: Radiotherapy as an adjunct in the management
of Merkel cell carcinoma. Cancer 65(1): 60-64, 1990.
** CELLULAR CLASSIFICATION **
MCC is usually found within the dermis, but may extend into the subcutaneous
tissue. The combination of vesicular nuclei with small nucleoli, abundant
mitoses, and apoptosis is considered to be characteristic of this tumor when
evaluated within the context of certain architectural features.
Histologically, MCC has been classified into three distinct subtypes:[1-3]
1. trabecular - cells are arranged in distinctly organoid clusters and
trabeculae with occasional ribbons; individual cells are round to
polygonal in shape and are compactly arranged; the tumor cell
cytoplasm is comparatively abundant and often well defined; mitoses
are few to moderate in number; this type of tumor is usually found
adjacent to adnexal structures, particularly hair follicles; it is the
least frequent histologic pattern identified.
2. intermediate - exhibits a solid and diffuse growth pattern; cells are
less compactly arranged and the cytoplasm is less abundant than in the
trabecular type; mitoses and focal areas of necrosis are frequently seen;
these tumors also arise adjacent to adnexa, but may invade the epidermis;
this is the most frequent histologic subtype identified; and tumors of
this type may behave in a clinically more aggressive manner than those of
the trabecular type.
3. small cell type - closely mimics small cell tumors of other sites; the
tumors arise in the dermis and appear as solid sheets and clusters of
cells; areas of necrosis and "crushing" artifact are frequently seen; the
clinical behavior of this subtype appears to be as aggressive as that of
the intermediate subtype.
References:
1. Haag ML, Glass LF, Fenske NA: Merkel cell carcinoma. Diagnosis and
treatment. Dermatologic Surgery 21(8): 669-683, 1995.
2. Ratner D, Nelson BR, Brown MD, et al.: Merkel cell carcinoma. Journal of
the American Academy of Dermatology 29(2 part 1): 143-156, 1993.
3. Gould VE, Moll R, Moll I, et al.: Neuroendocrine (Merkel) cells of the
skin: hyperplasias, dysplasias, and neoplasms. Laboratory Investigation
52(4): 334-353, 1985.
** STAGE INFORMATION **
There is no widely accepted or standardized staging classification based upon
prognosis. A staging system based upon clinical presentation is as follows:[1]
Stage I: Primary tumor, with no evidence of spread to lymph nodes or distant
sites.
Stage II: Regional node involvement, but no evidence of distant metastases.
Stage III: Presence of systemic metastases beyond the regional lymph nodes.
References:
1. Haag ML, Glass LF, Fenske NA: Merkel cell carcinoma. Diagnosis and
treatment. Dermatologic Surgery 21(8): 669-683, 1995.
** TREATMENT OPTION OVERVIEW **
The designations in PDQ that treatments are "standard" or "under clinical
evaluation" are not to be used as a basis for reimbursement determinations.
** STAGE I MERKEL CELL CARCINOMA **
Wide local excision has been recommended whenever possible.[1-3][Level of
evidence: 3iiiD] Frozen section control has also been recommended, especially
when the tumor is in an anatomical site that is not amenable to wide margins.
Some authors have advocated the use of Mohs micrographic surgery as a
tissue-sparing technique, but comparatively few cases have been treated in this
manner.[2,4] The role of elective lymph node dissection (ELND) in the absence
of clinically positive nodes is controversial. ELND has been recommended for
larger tumors, tumors with greater than 10 mitoses per high-power field,
lymphatic or vascular invasion, and the small-cell histologic subtypes.[1-3]
There are no data available with regard to the role of sentinel lymph node
mapping and biopsy in the management of MCC.
Radiation therapy to the primary site after excision and to the regional lymph
node basin has been advocated by some authors;[1,2,4,5] however, others have
found no advantage in local or regional control with adjuvant radiation therapy
in comparison with aggressive surgical therapy.[3] In general, radiation
therapy has been recommended for larger tumors, those with lymphatic invasion,
tumors approaching the surgical margins of resection, and locally unresectable
tumors. Total doses of 40 Gy to 60 Gy to the surgical bed and the draining
regional lymphatics have been used.[1,2,5,6] For unresected tumors or tumors
with microscopic evidence of spread beyond resected margins, doses of 56 Gy to
65 Gy have been recommended.[1][Level of evidence: 3iiiD]
References:
1. Haag ML, Glass LF, Fenske NA: Merkel cell carcinoma. Diagnosis and
treatment. Dermatologic Surgery 21(8): 669-683, 1995.
2. Ratner D, Nelson BR, Brown MD, et al.: Merkel cell carcinoma. Journal of
the American Academy of Dermatology 29(2 part 1): 143-156, 1993.
3. Yiengpruksawan A, Coit DG, Thaler HT, et al.: Merkel cell carcinoma.
Prognosis and management. Archives of Surgery 126(12): 1514-1519, 1991.
4. Goepfert H, Remmler D, Silva E, et al.: Merkel cell carcinoma (endocrine
carcinoma of the skin) of the head and neck. Archives of
Otolaryngology, Head and Neck Surgery 110(11): 707-712, 1984.
5. Gollard R, Weber R, Kosty MP, et al.: Merkel cell carcinoma. Review of
22 cases with surgical, pathologic, and therapeutic considerations.
Cancer 88(8): 1842-1851, 2000.
6. Marks ME, Kim RY, Salter MM: Radiotherapy as an adjunct in the management
of Merkel cell carcinoma. Cancer 65(1): 60-64, 1990.
** STAGE II MERKEL CELL CARCINOMA **
Wide local excision of the primary tumor, whenever possible, and regional lymph
node dissection have been recommended.[1,2][Level of evidence: 3iiiD] Although
most authors advocate the use of adjuvant radiation therapy,[1,3-5] others have
found no advantage in local or regional control with adjuvant radiation
compared with aggressive surgery alone.[2] In general, the primary site and
regional lymph node-bearing areas are included in the radiation field. The
role of adjuvant chemotherapy remains unproven, but is advocated by some
authors.[1,6,7] The chemotherapy regimens that have been employed are similar
to those used for patients with small cell lung cancer. (See the PDQ summary
on Small Cell Lung Cancer Treatment for chemotherapeutic options.)
References:
1. Haag ML, Glass LF, Fenske NA: Merkel cell carcinoma. Diagnosis and
treatment. Dermatologic Surgery 21(8): 669-683, 1995.
2. Yiengpruksawan A, Coit DG, Thaler HT, et al.: Merkel cell carcinoma.
Prognosis and management. Archives of Surgery 126(12): 1514-1519, 1991.
3. Ratner D, Nelson BR, Brown MD, et al.: Merkel cell carcinoma. Journal of
the American Academy of Dermatology 29(2 part 1): 143-156, 1993.
4. Goepfert H, Remmler D, Silva E, et al.: Merkel cell carcinoma (endocrine
carcinoma of the skin) of the head and neck. Archives of
Otolaryngology, Head and Neck Surgery 110(11): 707-712, 1984.
5. Marks ME, Kim RY, Salter MM: Radiotherapy as an adjunct in the management
of Merkel cell carcinoma. Cancer 65(1): 60-64, 1990.
6. Tai PT, Yu E, Winquist E, et al.: Chemotherapy in neuroendocrine/Merkel
cell carcinoma of the skin: case series and review of 204 cases.
Journal of Clinical Oncology 18(12): 2493-2499, 2000.
7. Feun LG, Savaraj N, Legha SS, et al.: Chemotherapy for metastatic Merkel
cell carcinoma. Review of the M.D. Anderson Hospital's experience.
Cancer 62(4): 683-685, 1988.
** STAGE III MERKEL CELL CARCINOMA **
Chemotherapy is the treatment most often used for patients with stage III
Merkel cell carcinoma (MCC).[1-5][Level of evidence: 3iiiDiii] Because of
morphologic and immunohistochemical similarities, the regimens employed are
similar to those used for patients with small cell lung cancer. MCC often
responds to chemotherapy initially, but the response is usually short-lived and
the impact of chemotherapy on survival is uncertain.[1-5] (See the PDQ summary
on Small Cell Lung Cancer Treatment for chemotherapeutic options.)
References:
1. Haag ML, Glass LF, Fenske NA: Merkel cell carcinoma. Diagnosis and
treatment. Dermatologic Surgery 21(8): 669-683, 1995.
2. Ratner D, Nelson BR, Brown MD, et al.: Merkel cell carcinoma. Journal of
the American Academy of Dermatology 29(2 part 1): 143-156, 1993.
3. Tai PT, Yu E, Winquist E, et al.: Chemotherapy in neuroendocrine/Merkel
cell carcinoma of the skin: case series and review of 204 cases.
Journal of Clinical Oncology 18(12): 2493-2499, 2000.
4. Feun LG, Savaraj N, Legha SS, et al.: Chemotherapy for metastatic Merkel
cell carcinoma. Review of the M.D. Anderson Hospital's experience.
Cancer 62(4): 683-685, 1988.
5. Voog E, Biron P, Martin JP, et al.: Chemotherapy for patients with
locally advanced or metastatic Merkel cell carcinoma. Cancer 85(12):
2589-2595, 1999.
** RECURRENT MERKEL CELL CARCINOMA **
Treatment options for patients with local recurrence are similar to those for
patients with stage II disease because the likelihood of regional lymph node
metastasis is very high.[1,2] Regional lymph node dissection and adjuvant
radiation therapy have been advised if the regional draining nodes have not
been previously treated. Chemotherapy may be an option for patients with
unresectable recurrent tumors or patients who have received their maximum
tolerated radiation dose.[1]
References:
1. Haag ML, Glass LF, Fenske NA: Merkel cell carcinoma. Diagnosis and
treatment. Dermatologic Surgery 21(8): 669-683, 1995.
2. Ratner D, Nelson BR, Brown MD, et al.: Merkel cell carcinoma. Journal of
the American Academy of Dermatology 29(2 part 1): 143-156, 1993.
Date Last Modified: 05/2001
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[Home] | [Search] | [Medical Q&A Forums] | [Patient Network] |
This information has been brought to you by
Med Help International,
licenced by the National Cancer Institute as a distributor of CancerNet.