Aggressive digital papillary adenocarcinoma is a rare tumor predominantly involving the distal end of digits. We examined 31 cases of this distinctive tumor for clinicopathologic, immunohistochemical, and follow-up data where available. Males were predominantly affected (n=29), with a mean age of 43 years (range, 14 to 67 y). Three lesions were reported in patients below the age of 20 years. All cases involved a finger (n=26) or a toe (n=5), with most involving the distal portion of the digit (n=29). Two lesions involved the base of the digit/webspace. Histopathologically, all tumors involved the dermis with subcutaneous extension in 14 cases. The lesions demonstrated a multinodular solid and/or cystic pattern, with focally infiltrative architecture in 21 cases. Papillary projections were: prominent (n=10), focal (n=15), or not identified (n=6). Within the solid component, tubular structures were present at least focally in all cases. Cytologic atypia ranged from mild (n=8) to moderate (n=20), but was focally severe in 3 cases. Mitotic count ranged from <1 to 18 per mm. Focal necrosis was seen in 6 cases. Immunohistochemically stained sections were available for review in 8 cases. Tumor cells were diffusely positive for MNF116 (3 of 3). Carcinoembryonic antigen and epithelial membrane antigen highlighted the luminal border of tubules (8 of 8). Smooth muscle actin (5 of 6) and calponin (6 of 6) highlighted a myoepithelial layer around tubular/glandular structures, as did p63 (2 of 2) and podoplanin (5 of 5). Follow-up after excision or amputation (n=23; range, 2 mo- to 21 y) revealed local recurrence (n=5) and metastatic disease (n=6; lymph node in 1, lungs in 4, and both lymph node and lung in 1). Metastases were noted at presentation in 2 cases (lymph node in 1 and lung in 1), but presented as late as 14 and 20 years in lymph node and lung, respectively. Only 1 patient died of metastatic disease 6 years after initial diagnosis, after multiple recurrences and lung metastases. Three patients were alive with progressive disease up to 24 months after developing lung metastases. Histopathologic features were not found to be predictive of outcome. The presence of tumor-associated myoepithelial cells histologically and immunohistochemically was not synonymous with benignity. Wide excision and partial digit amputation significantly reduced recurrence and metastatic rates. Delayed occurrence of metastases and a protracted course despite metastatic disease, necessitates long-term follow-up. As the name implies a malignant neoplasm, the rubric "aggressive" is unnecessary.

We report two cases of a CD8-positive lymphoid proliferation presenting as solitary lesions on the ear and nose, respectively. Histopathologically, both cases were characterized by a diffuse non-epidermotropic dermal proliferation of clonal medium-sized CD8-positive T-lymphocytes with a lymphoblast-like appearance, having cells with large folded nuclei, prominent nucleoli and ample amphophilic or pale eosinophilic cytoplasm. Staging procedures excluded systemic involvement, and both lesions were successfully treated with localised radiotherapy without evidence of recurrence after 12 and 24 months' follow up, respectively. Previously reported cases on the ear had similar clinicopathological and immunophenotypical features, and together raise the possibility of a distinct entity, an indolent CD8-positive lymphoid proliferation.

Early lesions of lichen sclerosus et atrophicus (LSA) may present as a mild lichenoid tissue reaction, occasionally together with basilar epidermotropism, mimicking early cutaneous T‐cell lymphoma, mycosis fungoides (MF) variant. We report a case of extragenital LSA in which both histological patterns were present in the same clinically homogenous and stable lesion. A 27‐year‐old man presented with a history of white atrophic plaques on the trunk. A biopsy of an abdominal lesion revealed epidermal thinning, a superficial perivascular lymphoid cell infiltrate with focal epidermotropism, mild nuclear atypia and perinuclear halos. Immunophenotyping showed decreased CD5 and CD7, with a slight predominance of CD8‐positive T‐lymphocytes. All these changes were suggestive of MF. However, a repeat biopsy 3 months later from the same stable plaque revealed features diagnostic of LSA. LSA mimicking early MF histologically has been reported in genital skin. Conversely, MF may clinically and histopathologically resemble LSA. With gene rearrangement studies, clonal proliferation may not be detected in early MF but has been reported to occur in LSA. Awareness of the histopathologic spectrum of LSA within a stable plaque is important to avoid a potential diagnostic pitfall, and should prompt a repeat biopsy. Suchak R, Verdolini R, Robson A and Stefanato CM. Extragenital lichen sclerosus et atrophicus mimicking cutaneous T‐cell lymphoma: report of a case.

Cutaneous schwannomas in their classical form are readily identified histologically. A number of variants, including ancient, cellular, epithelioid, plexiform, microcystic and neuroblastoma-like, may cause diagnostic difficulty and rarely be confused with malignancy. Neuroblastoma-like schwannoma was first described by Goldblum et al. in 1994, and very few cases have since been reported. It is a benign sporadic neoplasm with no reported association with neurofibromatosis, and is characterized histologically by small round lesional cells surrounding collagenous cores forming rosette-like structures. The differential diagnosis includes other lesions with the formation of rosettes including neuroblastoma, low-grade fibromyxoid sarcoma and dendritic cell neurofibroma, as well as primitive neuroectodermal tumors and rare malignant transformation in a schwannoma. We describe two further cases of this rare entity and review the literature on the subject. Our first case additionally has a plexiform multinodular pattern, a feature described in only one previous report.

Epithelioid angiosarcomas are rare aggressive neoplasms that occur most frequently in deep soft tissues. Primary cutaneous lesions are rare, and there are discrepant findings in the literature regarding their behavior. In this study, we report a series of 13 cases of primary cutaneous epithelioid angiosarcoma and analyze their clinicopathologic features. The tumors arising in the conventional settings for cutaneous angiosarcoma (ie, in the head and neck region of elderly patients, and those occurring postradiation or associated with lymphedema) were excluded. Primary cutaneous epithelioid angiosarcoma occurred in adults (mean age, 66 y) with an equal sex distribution, and presented as solitary (n=10) or multiple (n=3) nodules ranging in size from 8 to 80 mm, with a predilection for the limbs (n=10). Histopathologically, the tumors comprised infiltrative sheets of atypical epithelioid cells within the dermis with or without the involvement of the subcutis. Vascular channel formation and intracytoplasmic lumina were seen, at least focally, in most cases. Mitoses were readily identified and necrosis was seen in 40% of the cases. The tumors were immunoreactive for vascular markers, with CD31 and FLI-1 offering the highest sensitivity. Pancytokeratin was positive in two thirds of the cases, and epithelial membrane antigen was positive in one-quarter of the cases. There was rare focal expression of Melan-A (n=2) and smooth muscle actin (n=3). Follow-up information was available for 11 patients. Six patients died of metastatic disease after a median follow-up of 12 months (range, 3 to 36 mo), and 1 patient died of unrelated causes. These findings suggest that primary cutaneous epithelioid angiosarcoma occurring outside the conventional settings of angiosarcoma is a highly aggressive malignant tumor with mortality rates in excess of 55% after 3 years.