Merkel Cell Tumor in a Trichilemmal Cyst: Collision or Association?

An 86-year-old white male presented with an erythematous, painless, slowly growing, and firm left thigh nodule. Histologic examination revealed a dermal proliferation of monomorphous cells arranged in trabeculae, nests, and sheets with an infiltrative growth pattern. The cells had a high nuclear-cytoplasmic ratio, finely granular nuclear chromatin, and nuclear molding. Numerous mitotic figures, apoptotic cells, and individual cell necrosis were present; lymphovascular invasion was identified. The tumor was attached, demonstrating pagetoid intraepithelial migration, to a follicular cyst lined by squamous epithelium, lacking a granular cell layer and filled with compact keratinous content, diagnostic of trichilemmal cyst. Immunohistochemical study revealed that tumor cells expressed pan-cytokeratin (CK), chromogranin, synaptophysin, neuron-specific enolase, and CK20 (dotlike staining pattern), thus supporting the diagnosis of Merkel cell carcinoma. The association of Merkel cell carcinoma with a cyst is an exceptionally rare occurrence. As a result of the prominent involvement of the cyst wall by tumor cells, we favor that in this case carcinoma arose in the trichilemmal cyst rather than being a collision tumor. This hypothesis is also supported by the recent observation that Merkel cells are frequently present within normal hair follicles, especially in the isthmic portion that corresponds with the area of origin of the trichilemmal cyst.

Merkel cell carcinoma: clinicopathological aspects of an unusual neoplasm

Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous cancer that predominately affects elderly Caucasians with fair skin and has a propensity for local recurrence and regional lymph node metastases. It can occur on the face, the trunk, the genitalia, and the perianal region. The median age of the patients is 69 years, but it may occur earlier and more frequently in immunosuppressed patients. MCC usually arises in the dermis and extends into the subcutis. It may be difficult to accurately diagnose MCC by light microscopy alone and ancillary techniques, including electron microscopy and immunohistochemistry, may be necessary for a definitive diagnosis. The management of MCC is dependent on the stage of the disease and is hampered by its rarity and lack of randomized trials. Nonetheless, for localized disease most guidelines include wide local excision of the primary tumor either alone or followed by radiation therapy. Sentinel lymph node biopsy can be helpful in staging and prognosis, but its benefit in survival remains to be seen. Systemic chemotherapy may be considered as an adjuvant following surgery or to treat locoregional or distant disease. The prognosis of MCC is variable. In patients with localized disease the course is indolent and is well-controlled with local excision alone. On the other hand, many tumors are aggressive and have a tendency for locoregional recurrence and distant metastases. Such patients have a grim prognosis, with a median survival of 9 months. Successful outcome most often is seen in patients with early diagnosis and complete excision.

Merkel cell carcinoma: a case report

Merkel cell carcinoma is an uncommon, highly malignant, primary cutaneous neuroendocrine tumour mostly occurring as a solitary nodule on the head or on the extremities. It has high recurrence rate. We hereby report a case of Merkel cell carcinoma in a young woman.

Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous cancer that predominately affects elderly Caucasians with fair skin and has a propensity for local recurrence and regional lymph node metastases. A variety of terms have been used to describe this tumor, including trabecular cell carcinoma, neuroendocrine or primary small cell carcinoma of the skin, and anaplastic cancer of the skin. Although the skin lesion is most commonly found on sun-exposed areas of the head and neck or extremities, it can occur on the trunk, genitalia, and perianal region. The median age is 69 years, but it may occur earlier and more frequently in immunosuppressed patients. Patients with MCC frequently present with a nonspecific erythematous or violaceous firm nodule or small plaque that may be surrounded by small satellite tumors. MCC usually arises in the dermis and extends into the subcutis. It may be difficult to accurately diagnose MCC by light microscopy alone and ancillary techniques, including electron microscopy and immunohistochemistry, may be necessary to make a definitive diagnosis. Management of MCC is dependent on stage of the disease and is hampered by its rarity and lack of randomized trials. Nonetheless, for localized disease most guidelines include wide local excision of the primary tumor either alone or with radiation therapy. Sentinel lymph node biopsy can be helpful in staging and prognosis, but its benefit in survival remains to be seen. Systemic chemotherapy, akin to regimens for small cell carcinoma of the lung, may be considered as an adjuvant following surgery or to treat locoregional or distant disease. The prognosis of MCC is variable. Some patients with localized disease have an indolent course and are well controlled with local excision alone. On the other hand, many tumors are aggressive and have a tendency for locoregional recurrence and distant metastases. Such patients have a grim prognosis with a median survival of 9 months. Successful outcomes are most often seen in patients with early diagnosis and complete excision.

Merkel cell carcinoma and multiple primary cancers

Merkel cell carcinoma (MCC) is an aggressive neuroendocrine tumor of the skin for which causative factors remain largely unknown. The site-specific risks of multiple primary cancers associated with MCC, which may provide insight into etiologic influences, have not been quantified in large population-based studies. We estimated the long-term risk of subsequent primary tumors after a first primary MCC (1,306 patients) and the risk of second primary MCC following other first primary cancers (2,048,739 patients) within 11 population-based cancer registries which report to the National Cancer Institute's Surveillance, Epidemiology, and End Results Program (1986-2002). Patients with first primary MCC were at significantly increased risk of developing a subsequent cancer [standardized incidence ratio (SIR), 1.22; 95% confidence intervals (95% CI), 1.01-1.45; observed (O = 122)], with significant excesses restricted to the first year after diagnosis (SIR, 1.71; 95% CI, 1.21-2.33; O = 39). Significantly elevated site-specific risks were observed for cancers of salivary gland (SIR, 11.55; 95% CI, 2.32-33.76; O = 3), biliary sites other than liver and gallbladder (SIR, 7.24; 95% CI, 1.46-21.16; O = 3), and non-Hodgkin lymphoma (SIR, 2.56; 95% CI, 1.23-4.71; O = 10). Nonsignificantly increased risks of 2-fold or higher were seen for chronic lymphocytic leukemia, and cancers of the small intestine and brain. A significantly increased 1.36-fold risk (95% CI, 1.19-1.55; O = 221) of MCC as a second primary malignancy was observed among patients with all other first primary cancers taken together. In particular, significant 3- to 7-fold excesses of MCC followed multiple myeloma (SIR, 3.70; 95% CI, 1.01-9.47; O = 4), chronic lymphocytic leukemia (SIR, 6.89; 95% CI, 3.77-11.57; O = 14), non-Hodgkin lymphoma (SIR, 3.37; 95% CI, 1.93-5.47; O = 16), and malignant melanoma (SIR, 3.05; 95% CI, 1.74-4.95; O = 16). Although enhanced medical surveillance may play a role, increased reciprocal risks suggest that MCC may share etiologic influences with other malignancies. Heightened awareness of the associations of lymphohematopoietic malignancies with MCC may facilitate early clinical recognition.

Merkel cell carcinoma: a report of 34 cases and literature review

BACKGROUND

Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer, with unclear histogenesis. To date there is no consensus on the optimal treatment of this neoplasm, with controversy surrounding the use of radiotherapy and chemotherapy. There are also limited data on biological behaviour and prognosis, with reported survival ranging from 31% at three years to 74% at five years.

METHOD

The medical records of 34 patients with a diagnosis of primary MCC, treated at two NHS trusts in Birmingham and Coventry, were reviewed. An extensive review of the English literature was also performed.

RESULTS

MCC occurred predominantly in Caucasians (97%) with a mean age of 75 years. Identified risk factors were a previous history of SCC (37%), BCC (18%) and AK (20%). Ten percent of patients showed evidence of immunocompromise. Most tumours were located on the extremity, where they reached a mean size of 2.1cm. Fifty percent had regional metastasis during the course of their disease. A sub group analysis of the excision margins showed that a 2-cm excision margin, extending to the deep fascia, resulted in a 50% incomplete excision rate and a 33% local recurrence rate. In contrast a 3-cm margin including deep fascia resulted in no incomplete excisions and a 10.5% local recurrence rate Prognosis was poor with a 40% 3-year survival. Combining the data from two trusts has produced a relatively large series and highlighted differences in patient characteristics and management between the units. We advocate a 3-cm excision margin, including fascia wherever possible, combined with post-operative radiotherapy to offer the best chance of local control. Survival is fairly dismal and in keeping with the aggressive nature of this tumour. The respective roles of radiotherapy and chemotherapy remain controversial.

[Merkel cell carcinoma]

Merkel cell carcinoma is a rare form of skin cancer of likely neuroendocrine origin wich affects mainly white population in sun-exposed areas. It is an aggressive tumor and survival is dependent on stage at the time of diagnosis. The staging evaluation include CT imaging and recently PET scan. Surgical excision with or without lymph node dissection, followed by postoperative radiotherapy in stage II disease, is the standard treatment of non metastatic disease. The role of adjuvant chemotherapy is still controversial. In patients with metastatic disease, chemotherapy regimens active in small cell lung cancer are generally used. The combination of cyclophosphamide, doxorubicin and vincristine (CAV) has an overall response rate of 75%, whereas the response rate of etoposide in combination with cisplatin or carboplatin is 60%. Experience with other therapeutic agents, such as tumor necrosis factor, interferon and octreotide is scanty. Recently, encouraging preliminary results with targeted agents have been reported. Our experience in 14 patients, four of whom treated with chemotherapy for advanced disease, is in agreement with literature

Non-Hodgkin lymphoma and skin cancer: A dangerous combination

There is a significant association between non-Hodgkin lymphoma, including chronic lymphocytic leukaemia, and both melanoma and non-melanoma skin cancer. This review highlights the existing data on the phenomenon of accelerated skin cancer in patients with non-Hodgkin lymphoma and specifically chronic lymphocytic leukaemia. The outcomes of patients with non-Hodgkin lymphoma (including chronic lymphocytic leukaemia) and non-melanoma skin cancer are worse than in patients without concomitant lymphoreticular malignancy, as shown by increased rates of local recurrence, regional metastasis and death. Pathogenic factors may be common between non-Hodgkin lymphoma and chronic lymphocytic leukaemia and skin cancer. The treatment of skin cancer in patients with non-Hodgkin lymphoma must factor in the worse prognosis and adapt standard therapeutic approaches to minimize the risk of metastasis and death. Preventive strategies and early detection are paramount in this high-risk population.

Merkel cell tumour of the external ear. Report of a case

Merkel cells carcinoma (MCC) is an uncommon skin lesion, considered a malignancy of the neuroendocrine system, which is found mainly in elderly people. Its incidence is highly correlated with sun exposure or immunodeficiency syndromes. MCC is often an aggressive tumour with high tendency for local recurrence, lymph node involvement and distant metastasis. To our best knowledge 20 cases originated from the auricle have been described, 2 of them arising from external ear canal. The authors report a case of the ear canal characterized by two others synchronous tumours and the occurrence of a malignant high grade lymphoma, in which contribute of the pathologist was essential for a critical review. MCC diagnosis is not always easy for its pathological and clinical features and it should always be considered in presence of lymphoma. A multidisciplinary approach is basic.

[Merkel cell carcinoma]

Merkel cell carcinoma (Mcc) is a very rare, malignant, neuroendocrine tumour. Mcc has an aggressive behavior, local recurrence, and regional or distant metastasis generally develop within a short period of time. At the Oral Medicine Department 158,056 patients were treated between 1970 and 2004. A single case of Mcc was diagnosed, in a 79-year-old woman. The tumour was localized to the upper lip. After successful cryosurgery and a 7-year tumour-free period, a new tumour developed in her palatine tonsil. It was an anaplastic carcinoma with neuroendocrine features, raising the possibility of a late haematogenous metastasis, a second field tumour, or a second primary tumour. The clinical, histological, immunohistochemical and genetic findings suggested that the tumour of the palatine tonsil is a second field tumour.

Merkel cell carcinoma (primary cutaneous neuroendocrine carcinoma): An overview on management

Merkel cell carcinoma is an uncommon but aggressive primary cutaneous neuroendocrine (small cell) carcinoma. There is ongoing debate regarding the optimal treatment of this disease. The early literature comprised small institutional studies with inherent weaknesses. Recent data have emerged from larger studies, including those from Australian institutions, that adds support to a multimodality approach as best practice. Despite this, the outcome for patients with unfavourable disease remains poor and in most series 25-30% of patients die as a direct result of Merkel cell carcinoma. The head and neck is the commonest site for presentation (50-60%) and wide excision (2-3 cm) of the primary lesion is usually recommended, although achieving this is often difficult within functional and cosmetic constraints. All clinically node-negative patients should be considered candidates for elective nodal treatment and those with clinical nodal disease should undergo nodal dissection and adjuvant radiotherapy. Recent evidence suggests that patients treated with surgery and adjuvant locoregional radiotherapy experience a better disease-free survival compared with those undergoing surgery alone. The role of platinum-based chemotherapy is evolving. The aim of this article is to discuss relevant issues in the management of a patient with Merkel cell carcinoma.

Merkel Cell Carcinoma Guidelines

Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous tumor that combines the local recurrence rates of infiltrative non-melanoma skin cancer with the regional and distant metastatic rates of thick melanoma. The mortality rate of MCC exceeds that of melanoma, and the 5-year disease-specific survival rate is 64%. These guidelines and most biomedical literature suggest that the workup of a patient with MCC should include chest radiograph and additional studies as clinically indicated. These guidelines, which the NCCN Non-Melanoma Skin Cancer Panel developed as a supplement to those for squamous cell and basal cell skin cancer, also outline treatment strategies.

For the most recent version of the guidelines, please visit NCCN.org

Pax-5 immunoexpression in various types of benign and malignant tumours: a high-throughput tissue microarray analysis

BACKGROUND

Pax-5 belongs to the Pax gene family transcription factors that play an important role in organogenesis and in B cell ontogeny. It is expressed in B cell non-Hodgkin's lymphoma (B-NHL), Hodgkin's lymphoma (HL) and neuroendocrine carcinomas. However, its expression in other tumour types is not fully explored.

AIMS AND METHODS

To determine Pax-5 expression in other tumour types, immunohistochemistry was performed on 3758 benign and malignant tumours using multiple tumour microarrays, as well as on whole sections.

RESULTS

Pax-5 was expressed in 108/118 (91.5%) B-NHLs, in 60/70 (85.7%) HLs and in 0/7 T cell lymphomas. In addition, Pax-5 was seen in 24/34 (70.6%) Merkel cell carcinomas, 42/53 (79.2%) small cell carcinomas, 1/164 (0.6%) breast carcinomas, 2/204 (1%) endometrial adenocarcinomas and 1/452 (0.2%) urothelial carcinoma of the bladder.

CONCLUSION

Despite its expression in a small subset of malignancies of epithelial origin, Pax-5 is still a good and reliable immunomarker in diagnosing B-NHL, HL and neuroendocrine carcinomas.

Sentinel lymph node biopsy for evaluation and treatment of patients with Merkel cell carcinoma: The Dana-Farber experience and meta-analysis of the literature

OBJECTIVE

To determine the diagnostic accuracy and usefulness of sentinel lymph node biopsy (SLNB) and computed tomographic scans in the initial evaluation and treatment of patients with Merkel cell carcinoma (MCC).

DESIGN

Single-institution case series and literature-based case-level meta-analysis.

SETTING

Academic cutaneous oncology clinic.Patients Sixty-one adults with biopsy-proven MCC (30 who had undergone SLNB) plus 92 cases from the literature of patients who had undergone SLNB.

MAIN OUTCOME MEASURES

Relapse-free survival.

RESULTS

In 122 patients with no nodal disease found by physical examination, SLNB findings revealed nodal involvement in 39 cases (32%). At 3 years, the recurrence rate for those with a positive SLNB was 3 times (60%) higher than for those with a negative SLNB (20%; P = .03). Patients with a positive SLNB who received adjuvant nodal therapy had a relapse-free survival rate of 51% at 3 years (n = 26) compared with 0% for patients who did not receive nodal therapy (n = 3; P < .01). In contrast, among patients with a negative SLNB there was no significant difference in 3-year relapse-free survival rates for those who did (90%; n = 24) or did not (70%; n = 19; P = .26) receive adjuvant nodal therapy. Using SLNB plus clinical follow-up as a gold standard, computed tomographic scans had low sensitivity (20%) for detecting MCC that had spread to the lymph node basin and low specificity for distant disease (only 4 of 21 "positive" scans were confirmed during 6 months of follow-up).

CONCLUSIONS

Sentinel lymph node biopsy detects MCC spread in one third of patients whose tumors would have otherwise been clinically and radiologically understaged and who may not have received treatment to the involved node bed. There was a significant benefit of adjuvant nodal therapy, but only when the SLNB was positive. Thus, SLNB is important for both prognosis and therapy and should be performed routinely for patients with MCC. In contrast, computed tomographic scans have poor sensitivity in detecting nodal disease as well as poor specificity in detecting distant disease.

Merkel cell carcinoma -- a rarity in the urogenital tract

BACKGROUND

Merkel cell carcinoma -- a rare, aggressive cancer of the skin integument - is being increasingly diagnosed but represents an absolute rarity in the urogenital tract.

CASE REPORT

We report on a 70-year-old man who was referred to us with suspected testicular cancer. The pathology report revealed a metastasized Merkel cell carcinoma. Fulminant disease progression under chemo-therapy (regimen as for small cell lung cancer) resulted in death 5 months later.

CONCLUSION

The patient described is considered to be the first to develop testicular metastasis derived from Merkel cell carcinoma. Besides neuroendocrine and epithelial antigen tests, somatostatin receptor scintigraphy is a helpful diagnostic tool. New receptor-associated therapies may allow more effective and less toxic treatment modalities in the mostly elderly or immune deficient patients.

Merkel cell cancer of the skin

Merkel cell carcinoma (MCC) is a rare malignant cutaneous tumor of the elderly with rapidly growing skin nodules found predominantly on sun-exposed areas of the body. The vast majority of patients present with localized disease, while up to 30% have regional lymph node metastases. Despite local excision and the incidence of local recurrence, regional lymph node metastases and distant metastases is high and usually occurs within 2 years of primary diagnosis. The optimal treatment for patients with MCC remains unclear. The best outcome is achieved with multidisciplinary management including surgical excision of primary tumor with adequate margins and post-operative radiotherapy (RT) to control local and regional disease. Patients with regional nodal metastases should be treated with lymph node dissection plus RT. Adjuvant chemotherapy (CT) should be considered as part of the initial management. In case of metastatic disease CT based on regimens used for small-cell lung cancer is the standard treatment of care.

Merkel Cell Carcinoma Arising from the Subcutaneous Fat of the Arm with Intact Skin

BACKGROUND

Merkel cell carcinoma is a rare malignant neuroendocrine neoplasm characteristically arising from the dermis of sunlight-exposed skin. It rarely arises outside the skin.

OBJECTIVE

We present a patient with primary Merkel cell carcinoma arising from subcutaneous fat, with no involvement of the overlying skin. We describe the clinical manifestations and magnetic resonance imaging (MRI) findings.

METHODS

We report a 63-year-old woman with a primary lesion of Merkel cell carcinoma that arose from the subcutaneous fat layer of the left arm. The lesion presented as a subcutaneous nodule with intact overlying skin. MRI showed that the nodular lesion was located entirely in the subcutaneous fat layer, with no involvement of the dermis. Peritumoral infiltration around the lesion and enlarged lymph nodes deep to the lesion were noted. The patient received wide excision of the lesion with dissection of the regional lymph nodes and adjuvant radiotherapy and chemotherapy.

RESULTS

Histopathologic examination confirmed the diagnosis of Merkel cell carcinoma with local lymphatic metastasis, and the lesion was completely located in the subcutaneous fat, with no involvement of the dermis. These findings were well correlated with MRI findings.

CONCLUSION

Primary Merkel cell carcinoma may arise from the subcutaneous fat and present as an entirely subcutaneous lesion with intact skin. MRI is helpful to evaluate the local extension of the lesion and regional lymphatic metastasis.

[Immunohistochemical diagnosis of metastases of small round cell carcinomas with undetected primary focus]

17 small round cell tumors of unkown primary site were studied. The main location was lymph nodes and brain. Immunohistochemical study was performed. One of the following diagnosis was obtained in 14 cases (82.4%): small cell carcinoma, Merkel cell carcinoma, melanoma, Ewing sarcoma family tumor. In other three cases (17.6%) tumor histogenesis was not determined definitively.

Cytopathologic features of olfactory neuroblastoma

BACKGROUND

Olfactory neuroblastoma (ONB) is an uncommon neoplasm arising from the olfactory mucosa. Because its cytopathology is largely limited to case reports, the goal was to evaluate a series of ONB cases, compare them with previously reported cases, and with a control group of pulmonary and cutaneous small cell neuroendocrine carcinoma (NEC).

METHODS

Six fine-needle aspiration (FNA) biopsies of metastatic ONB and one case with imprint smears of primary ONB were recovered from files. Aspirates from seven FNA cases of metastatic pulmonary small cell NEC and four cases of metastatic Merkel cell carcinoma to the head and neck functioned as a control group and were compared with those of ONB.

RESULTS

Seven cases from 4 patients included 3 males (ages 33-39 yrs) and 1 female (age 58 yrs). Aspirates were acquired from soft tissues of the neck (three cases), cervical lymph nodes (two cases), parietal scalp (one case), and imprint of a nasal mass (one case). A correct cytologic diagnosis of metastatic ONB (five cases) or malignant small round cell tumor (one case) was made in six cases. One aspirate was misdiagnosed as a reactive lymph node. The single primary tumor and five of six metastatic tumors were histologically confirmed. Cytologic features were similar in all cases. These included high cellularity (seven of seven cases), distribution as single forms and cell clusters (seven of seven cases), a two-cell population of intact and apoptotic nuclei (seven of seven cases), nuclear molding (seven of seven cases), paranuclear 'blue bodies' (five of seven cases), necrosis (five of seven cases), and absence of lymphoglandular bodies (seven of seven cases). Unlike prior reports, no case exhibited rosettes or fibrillar neuropil on smears. All examples from the control group displayed nearly identical cytomorphologic features to those of the study group.

CONCLUSIONS

The cytopathology of metastatic ONB is nonspecific unless fibrillar neuropil is identified. Nonetheless, a cytopathologic diagnosis of metastatic ONB can be made with confidence in nearly all patients if a well documented history of ONB exists. Minus such a clinical context, aspirates of metastatic ONB may be mistaken for metastatic pulmonary small cell NEC, cutaneous neuroendocrine (Merkel cell) carcinoma, and even small cell lymphoma.

Biopsia selectiva de ganglio centinela en tumores cutáneos no melanoma

PURPOSE

To assess the feasibility of the Sentinel lymph node biopsy (SLNB) technique in cutaneous non-melanoma malignancies.

MATERIALS AND METHODS

Nine patients were retrospectively evaluated performing a scintigraphy with 99mTc-nanocolloid. On the day of the surgery, an initial dynamic study and static images were obtained. The first drainage station visualized was considered the sentinel node (SLN). The SLN position was marked on the skin and after a correct localization in the surgical field with a gamma probe the SLN was obtained. Patients of this study have been followed up for 8 to 48 months.

RESULTS

Lymphoscintigraphy detected the sentinel node in 88,8 % of our studies (the SLN was not observed in a patient with a Merkel's tumour on the back). The SLN was identified intraoperatively in those patients with positive imaging. Those cases without scintigraphic demonstrated migration were also not found intraoperatively. Histopathological analysis of the SLN showed non metastatic disease and none patient developed metastases or local recurrence in the monitoring period.

CONCLUSIONS

Sentinel node biopsy can be applied to certain cutaneous non-melanoma malignancies. In patients with unclear drainage and to avoid unnecessary lymphadenectomy, the technique offers clear advantages. In our study the SLN analysis was related to the clinical progress. A large number of patients should be examined to truly assess the benefit of this technique in this kind of malignancies and to determinate when the technique must be performed.