Boštjan Luzar

Sebaceous carcinoma arising in nevus sebaceus of Jadassohn: a clinicopathological study of five cases.

The authors report a small series of sebaceous carcinoma developing in nevus sebaceus of Jadassohn (also known as organoid nevus) and analyze similar cases reported in the literature. All of our patients were females (age range 57-71 years; median 60 years) who had the organoid nevus on the scalp, face, or nuchal area, the rest of which was recognized clinically and/or histologically. All sebaceous carcinomas manifested unquestionable architectural (asymmetry, invasive growth) and cytological features of a carcinoma (cellular and nuclear pleomorphism, plentiful atypical mitoses, necroses en masse), demonstrated unambiguous sebaceous differentiation in the form of mature sebocytes, and lacked other differentiations. The sebaceous carcinoma was always accompanied by other benign or malignant adnexal lesions such as sebaceoma, syringocystadenoma papilliferum, syringocystadenocarcinoma papilliferum, trichoblastoma, tricholemmoma, desmoplastic tricholemmoma, or syringoma. In three cases, prominent mucinous metaplasia of sweat ducts and glands was seen. In two of these cases, sweat ducts exhibited hyperplastic changes. The analysis of the previously published material and our cases indicates that sebaceous carcinoma arising in organoid nevus has a female predilection and tends to occur in elderly patients. It may involve any site where nevus sebaceus typically occurs. Clinically, the tumor presents as a solitary nodule, ulcerated tumor, or mass, often with a recent history of rapid growth. It may arise alone, but it occurs more frequently as part of multiple benign and malignant adnexal tumors. The lesion does not seem to be associated with Muir-Torre syndrome. The rest of organoid nevus is usually recognized both clinically and microscopically, although large tumors may overgrow and mask the nevus. The tumor seems to be a low-grade carcinoma in terms of clinical behavior.

Cutaneous carcinosarcoma – basal cell carcinoma with osteosarcoma

To the Editor, The diagnostic clue for primary skin carcinosarcoma is an intimate admixture of epithelial and mesenchymal components, both of which must be malignant. Defined as such, primary skin carcinosarcoma is an exceedingly rare biphasic neoplasm. In an excellent review of 38 primary skin carcinosarcomas reported in the literature and of their own four cases, Tran and colleagues have convincingly demonstrated that two types of primary skin carcinosarcomas can be separated: epidermal-derived and adnexal carcinosarcomas. They showed in addition that this separation has also prognostic implications: while a 5-year disease-free survival is 70% for epidermal-derived carcinosarcomas (low-risk tumors), it drops sharply to 25% for adnexal-type carcinosarcomas (high-risk tumors). Nevertheless, since the follow up for the majority of cases is short, long-term prognosis still remains unknown. Here, we describe additional case of primary skin carcinosarcoma that was composed of basal cell carcinoma and osteosarcoma. A 53-year-old male presented with a slowly growing lesion of several months duration on the abdominal skin. An asymmetrical whitish tumor measuring 17 mm in greatest diameter was seen, which was centrally ulcerated and unsharply demarcated from the surrounding normal tissue. The whole resection specimen was examined histologically. On histology, a biphasic tumor was seen. The epithelial component was composed of large basaloid nodules showing peripheral palisading. The tumor cells within the nodules showed brisk mitotic activity. A retraction artefact was present between epithelial nodules and surrounding mucin-rich stroma. Intermingled with epithelial islands were spindle cells containing areas of focally calcified osteoid, rimmed by osteoblasts (Fig. 1). Mitoses in the spindle cell component were common, up to 3 per 1 high power field (Fig. 2). While epithelial component was EMA and CK17 positive but vimentin negative, inverse immunophenotype was seen in the spindle cell component. CK 17 has been demonstrated by Kurzen and colleagues to be consistently expressed in basal cell carcinomas and tumors with follicular differentiation. On the basis of a typical histomorphology and immunohistochemistry showing dual differentiation (e.g., Fig. 1. Basal cell carcinoma intermingled with foci of osteosarcoma – a primary cutaneous carcinosarcoma.

Cutaneous clear cell sarcoma: report of three cases of a potentially underestimated mimicker of spindle cell melanoma.

Abstract: Clear cell sarcoma is a unique soft tissue tumor with distinct microscopic features that include a nested or fascicular pattern of spindle cells accompanied by larger wreath-like giant cells scattered throughout. It harbors a unique EWSR1-ATF1 gene fusion secondary to a t(12;22)(q13;q12) translocation. Recently, it was reported that clear cell sarcoma can occur in the skin and mimic a broad spectrum of entities, including spindle cell melanoma. Here, we describe 3 new cases of clear cell sarcoma of the skin, all of which were confirmed molecularly. The patients, a 12-year-old boy, a 29-year-old woman, and a 60-year-old man, had cutaneous lesions on the thigh, dorsum of foot, and sole, respectively. All 3 lesions were originally considered suspicious of spindle cell melanoma. Microscopically, the lesions featured nodular proliferation centered in the dermis that consisted of discrete fascicles of spindle cell enmeshed by thin fibrous strands. Wreath-like cells were present in all cases. Tumor cells were positive for S100 protein (3 of 3 cases), melan A (2 of 3 cases), HMB 45 (1 of 3 cases) although a junctional melanocytic proliferation was seen in 1 case. Sentinel lymph node biopsy was negative in 2 patients. Follow-up was uneventful in 2 patients, whereas the other patient developed a lymph node metastasis 5 months after primary tumor excision. This study confirms that malignant dermal tumors that mimic but do not exactly replicate spindle cell melanoma should raise suspicion for cutaneous clear cell sarcoma and prompt the investigation for the confirmatory gene fusion t(12;22).

Deep Penetrating Nevus: A Review

CONTEXT Deep penetrating nevus is a distinctive melanocytic lesion that may simulate melanoma both clinically and histologically. OBJECTIVE To review clinical and histologic features of deep penetrating nevi and discuss their differential diagnosis, especially regarding melanoma. DATA SOURCES The literature on deep penetrating nevi is reviewed and supplemented by our experiences with deep penetrating nevi. CONCLUSIONS One or more disturbing histologic features may frequently be found in deep penetrating nevi, including asymmetry, plump but fairly regular nests of melanocytes in the dermis, cytologic atypia with some nuclear pleomorphism, a small to medium-sized eosinophilic nucleolus, absence of maturation, occasional presence of normal dermal mitoses, and a patchy mononuclear inflammatory cell infiltrate. Although unusual, such histologic features should not be regarded as a sign of malignancy in deep penetrating nevi.

Signet Ring Cell Angiosarcoma: A Hitherto Unreported Pitfall in the Diagnosis of Epithelioid Cutaneous Malignancies

Abstract:We report 2 cases of cutaneous epithelioid angiosarcoma featuring predominantly signet ring cells. The patients—a woman, 68 years of age, and a man, 85 years of age, respectively—were referred for slowly growing indurated plaques on their parietal and retroauricular skin. Microscopic examination showed diffuse dermal proliferations comprising polygonal cells and relatively abundant cytoplasm. Because the tumor cells often were distended by variably sized vacuoles pushing the nuclei to the periphery, the nuclear profile tended toward a crescent-like morphology. Abortive luminal formations were recognized. The tumor cells were positive for CD31, CD34, and D2-40/podoplanin, with no expression of epithelial or melanocytic markers. In 1 case, upon ultrastructural examination of paraffin-embedded tissue—cut from wax tissue and reprocessed—the optically empty spaces were surrounded by a membrane with ultrastructural features identical to those of the outer cell membrane, suggesting that these spaces corresponded to the formation of primitive intracytoplasmic lumina within the tumor cells. A few Weibel–Palade bodies also were noted. Our report offers further evidence that epithelioid angiosarcoma of the skin has a broad microscopic spectrum and that tumors displaying a preponderant population of signet ring cells pose further diagnostic challenges. A brief overview of cutaneous malignant tumors in the differential diagnosis of signet ring cell angiosarcoma is provided.

Intravascular Kaposi’s sarcoma – a hitherto unrecognized phenomenon

Background:  Based on the spectrum of histological features, Kaposi’s sarcoma (KS) is grouped into patch, plaque and nodular stages. The histological changes overlap, especially with lesional evolution. To date, intravascular KS is undocumented.

Angiokeratoma-like changes in extragenital and genital lichen sclerosus

Hemorrhagic blisters have rarely been described developing in the background of either genital or extragenital lichen sclerosus and have invariably been designated clinically as telangiectatic, hemorrhagic or bullous lichen sclerosus. We describe three patients with extragenital and genital lichen sclerosus, who presented clinically with hemorrhagic plaques and/or papules. In addition to the classical histology of lichen sclerosus, dilated, congested and focally thrombosed vascular channels lined by flat endothelium were seen within the sclerotic dermal collagen. They were in close proximity to and even in contact with the overlying epidermis and thus mimicked an angiokeratoma. Angiokeratoma‐like changes in lichen sclerosus represent secondary features because of damage to the dermis by lichen sclerosus and are characterized histologically by ectatic thin‐walled vascular spaces in the papillary dermis intimately associated with the epidermis. Increased venous pressure, local trauma, degenerative changes in the elastic tissue of the vessel wall and/or surrounding supportive tissue, as well as abnormalities in the extracellular protein network, appear to be implicated in their pathogenesis.

Primary cutaneous nevoid melanoma with Homer-wright rosettes: a hitherto unrecognized variant with immunohistochemical and ultrastructural study.

We report a case of cutaneous nevoid melanoma manifesting as a growing and pruritic pigmented lesion of the back in a 43-year-old woman. The lesion measured 1.2 cm in its largest dimension. The salient microscopic features were discrete dermal nests of palisading tumor cells and a central fibrillary tangled core. Other features were microscopically consistent with melanoma: irregular tumor cell nesting associated with upward migration of melanocytes and consumption of the epidermal component, lack of maturation, expansile growth pattern, and a tendency to confluence of the dermal nests. No prominent mitotic activity was recognized. Breslow thickness was 1.3 mm. Tumor cells were positive for HMB45, Melan A, tyrosinase, and S100 protein. The MIB-1/ki-67 proliferative index was 2%. Histologic examination of a biopsy sample from the axillary sentinel lymph node was positive for small foci of melanocytic cells measuring 0.04 mm in their largest dimension.

Cutaneous Osteoblastic Osteosarcoma: Report of 2 New Cases Integrated With SATB2 Immunohistochemistry and Review of the Literature.

Abstract:We report 2 cases of primary dermal osteosarcoma. The patients were an 88-year-old man and a 72-year-old man complaining of masses occurring in the ear pavilion and the palm, deemed suspicious for basal cell carcinoma and metastatic colonic carcinoma, and were treated by resection. Microscopically, both featured a dermal lesion mostly composed of atypical spindle cells within a fibrous to hyaline matrix often showing mineralization. Osteoid material was rimmed by atypical tumor cells and was also associated with osteoclast-like giant cells. Tumor cells were positive for SATB2 and negative for markers of epithelial (low-molecular and high-molecular weight cytokeratins, epithelial membrane antigen, p63), melanocytic (S100 protein, HMB45, Melan A), and skeletal/smooth muscle differentiation (desmin, myogenin). No further therapy has been administered. Follow-up at 6 (case 1) and 8 months (case 2) was uneventful. A brief differential diagnosis discussing cutaneous tumors capable of showing osseous differentiation is summarized, along with a review of the pertinent literature. The specificity and sensitivity of SATB2 is also shortly addressed.