Intraepidermal and dermal Merkel cell carcinoma with squamous cell carcinoma in situ: a case report with review of literature

Merkel cell carcinoma (MCC), a rare aggressive primary cutaneous neuroendocrine carcinoma, occurs on sun‐damaged skin, especially in the elderly. Its unique co‐expression of cytokeratin 20 (CK20) and neuroendocrine markers, including neuron‐specific enolase (NSE), is diagnostic. Most MCCs are located in the dermis, rarely has an intraepidermal component been reported. We report a case of MCC with an intraepidermal component admixed with squamous cell carcinoma in situ (SCCIS). We were able to identify the differences in the immunohistochemical expression pattern between that of the intraepidermal and the dermal components. Most intraepidermal neoplastic cells of MCC in this case showed a less intense immunoreactivity to CK20 and NSE compared to that of dermal neoplastic cells. This case reports an unusual occurrence of combined SCC and MCC that shows both intraepidermal and dermal components. Sirikanjanapong S, Melamed J, Patel R. Intraepidermal and dermal Merkel cell carcinoma with squamous cell carcinoma in situ: a case report and review of literature.     

Eccrine porocarcinoma, tricholemmal carcinoma and multiple squamous cell carcinomas in a single patient.

A 75-year old woman without remarkable medical history presented with a large eccrine porocarcinoma of the trabelucar type located on her leg. This tumor was associated with two invasive squamous cell carcinomas of the legs, two Bowen's diseases of her thigh and arm and multiple actinic keratoses of the face. Despite major surgery, local recurrence of the porocarcinoma was observed 6 months later. During the 3-year follow-up after a second surgical intervention, this lesion did not reccur, but the patient developed a rapidly enlarging ulcerated tumor of the forehead which proved to be tricholemmal carcinoma. Although no carcinogenetic factor or familial history of multiple neoplasms could be evidenced, the occurrence of multiple tumors of various histogenesis over a 1 year period of time is unlikely to be fortuitous. Such an association of rare adnexal neoplasms has not yet been described.     

Clear-cell porocarcinoma in situ: a cytologic variant of porocarcinoma in situ.

Poromas are benign neoplasms composed of poroid and cuticular cells. Four histopathologic variants of poromas are accepted, according to the architectural features of the neoplasm: hidroacanthoma simplex or intraepidermal poroma; eccrine poroma, which is a poroma connected to the epidermis that extends to superficial dermis; dermal duct tumor, which develops when the neoplasm is composed of small, solid aggregations of poroid and cuticular cells confined to the dermis with little or no connection with the epidermis; and poroid hidradenoma, which is a solid-cystic, dermal poroma. The malignant counterpart of hidroacanthoma simplex is named malignant hidroacanthoma simplex or porocarcinoma in situ. This report describes an example of clear-cell malignant hidroacanthoma simplex, a cytologic variant of porocarcinoma in situ, which, to our knowledge, has not been previously reported. In contrast with other clear-cell neoplasms, a relation with diabetes mellitus could not be clearly established in this case.     

皮肤鳞状细胞癌临床和病理分析

目的探讨皮肤鳞状细胞癌的临床和病理特点。方法收集2009--2012年经组织病理诊断为皮肤鳞状细胞癌的58例患者的临床及病理资料,对临床和组织病理学特征进行回顾分析。结果皮肤鳞状细胞癌高峰发病年龄为70～89岁,皮损见于头面部27例（46．55％）,外生殖器部位20例（34．48％）,四肢9例（15．52％）,躯干2例（3．45％）。临床上表现为结节隆起型27例,占46．55％,深在浸润型19例,占32．76％,溃疡型12例,占20．69％。组织病理表现为经典型51例,特殊类型7例（疣状型5例、腺性鳞癌1例、透明细胞型1例）。结论皮肤鳞状细胞癌好发于老年人曝光部位,应及早进行组织病理学检查以明确诊断,提高患者生存率。     

Cutaneous clear cell squamous cell carcinoma in situ : clinical, histological and immunohistochemical characterization

BACKGROUND: Clear cell squamous cell carcinoma in situ (SCCIS) has not been defined in the literature with respect to its clinical, histological, and immunohistochemical features. METHODS: Nearly 1500 consecutive cases of SCCIS were assessed for percent clear cell change. The clinical features of all SCCIS with >or=10% clear cell change, including age, sex and site distribution, were compared with classical SCCIS using chi-square analysis. PAS special staining and immunohistochemical analysis with 11 cell markers were performed to characterize the clear cell of origin. RESULTS: Eighty SCCIS cases with a spectrum of clear cell change of >or=10% were identified. Six cases with >or=80% clear cells were defined as clear cell SCCIS. The clinical features of the cases did not vary significantly from classical SCCIS. Antibodies labeling outer root sheath (ORS) cells also labeled clear cells in the cases and included K8.12 (labeling CK13 and CK16), cellular retinoic acid binding protein II, CAM 5.2 and CK15. Antibodies that did not label ORS cells, but did label eccrine glands (CK7 and CK18) or sebocytes (EMA), also did not label the cases. CONCLUSION: Clear cell change in SCCIS is part of a spectrum which displays ORS differentiation.     

Thermal keratoses and squamous cell carcinoma in situ associated with erythema ab igne

A 60-year-old black woman had a large hyperkeratotic lesion and multiple smaller hyperkeratotic papules and plaques on the lower part of her legs in areas of erythema ab igne. Histologic examination of the largest lesion showed hyperplastic carcinoma in situ and the multiple smaller lesions showed varying degrees of squamous cell atypia and dermal elastosis. Histologically, these lesions were identical to solar-induced atypia, indicating that squamous cell carcinoma arising in erythema ab igne may be biologically similar to actinic carcinoma. Discussed here are clinical and histologic features of the thermal-induced lesions and other types of thermal-induced carcinomas.     

Invasive squamous cell carcinoma after treatment of carcinoma in situ with 5% imiquimod cream

Squamous cell carcinoma in situ has the potential to progress to invasive squamous cell carcinoma. This report presents two cases of punch biopsy-proven squamous cell carcinoma in situ, treated with once-daily application of 5% imiquimod cream for 6 weeks. Both patients developed moderate local inflammatory reactions during treatment. The first patient demonstrated clinical clearance of the scalp lesion after treatment. Two months later, he re-presented with a subcutaneous nodule at the same site. Histology was consistent with recurrent squamous cell carcinoma. Five months following excision of the recurrent tumour, he presented with metastatic squamous cell carcinoma to a cervical lymph node. The second patient had low-grade chronic lymphocytic leukaemia and presented with squamous cell carcinoma in situ of the leg that failed to clear clinically after treatment with imiquimod. He presented 4 months later with a focus of invasive squamous cell carcinoma within the lesion.     

皮肤Merkel细胞癌伴鳞状细胞癌一例

患者男,76岁,因左耳前肿物2个月,破溃1个月就诊.2个月前左耳前面颊部无明显诱因出现一约黄豆大小的丘疹,迅速长大,1个月前表面出现破溃,无自觉症状.2周前左耳后出现一蚕豆大小肿大的淋巴结,有触痛,抗炎治疗后缩小.     

Merkel细胞癌合并原位鳞状细胞癌一例并文献复习

Merkel细胞癌是一种罕见的、具有高度侵袭性的皮肤神经内分泌癌,好发于老年人的日光暴露部位,尤其是头颈部(41%～50%),其次是四肢(32%～38%)。Merkel细胞癌可与鳞状细胞癌、鲍温病、基底细胞癌等皮肤肿瘤合并发生。我们报道一例发生在非光暴露部位的Merkel细胞癌合并原位鳞状细胞癌,并对相关文献进行复习。     

Subsequent cancers after in situ and invasive squamous cell carcinoma of the skin

OBJECTIVES: To compare cancer risks after in situ and invasive squamous cell carcinoma (SCC) of the skin and to determine whether these 2 forms of cancer differ in prognostic significance. PATIENTS: Subsequent events after in situ and invasive SCC were studied in the Swedish Family-Cancer Database, in which cancer data were obtained from the Swedish Cancer Registry from 1958 to 1996. Among 22293 patients with in situ SCC, 3940 had first invasive cancer; among 17637 patients with invasive SCC, 3624 had a second occurrence of cancer. MAIN OUTCOME MEASURE: Standardized incidence ratios (SIRs), ratios of the observed to expected number of cases, served as a measure of relative risk. For overall risks, cases diagnosed within the first year of follow-up were omitted. RESULTS: The median age of onset was 72 to 73 years for in situ and invasive SCC, respectively. Standardized incidence ratios of all cancers were increased after in situ SCC (men-women, 1.5:1.3) and invasive SCC (men-women, 1.9:1.5). The subsequent occurrences of cancer and their SIRs were similar after in situ and invasive SCC, with skin cancer showing the highest SIR of 6.4:10.0. Among discordant cancers, increased SIRs were recorded for melanoma and a group of malignant neoplasms observed in patients with immunosuppression, including lymphoma and oral cancers. Subsequent cancers in the salivary glands and nasal cavity also showed increased SIRs, particularly after invasive SCC. CONCLUSION: Risks of subsequent cancers, including skin cancer, melanoma, and internal cancers, showed similar patterns in patients with in situ and invasive SCC, suggesting that the 2 groups have a similar susceptibility to cancer.