Update on Malignant Sweat Gland Tumors.

Malignant sweat gland tumors are rare cutaneous neoplasms, traditionally separated according to their behavior into low- and high-grade malignant. There is significant morphologic overlap, and outright malignant tumors may show relatively bland histologic features. They may, therefore, be mistaken easily for benign neoplasms. Recognition of these tumors and accurate diagnosis is important for early treatment to prevent aggressive behavior and adverse outcome. This article provides an overview of 4 important entities with emphasis on diagnostic pitfalls, differential diagnosis and recent developments. Microcystic adnexal carcinoma, squamoid eccrine ductal carcinoma, aggressive digital papillary adenocarcinoma, and spiradenocarcinoma are discussed in detail.

The effect of topical diclofenac 3% and calcitriol 3 µg/g on superficial basal cell carcinoma (sBCC) and nodular basal cell carcinoma (nBCC): A phase II, randomized controlled trial.

BACKGROUND: Nonsteroidal anti-inflammatory drugs and vitamin-D derivatives can target signaling pathways activated in basal cell carcinoma (BCC). OBJECTIVE: We investigated the efficacy of topically applied diclofenac sodium 3% gel, calcitriol 3 µg/g ointment, and a combination of both in superficial BCC (sBCC) and nodular BCC. METHODS: Patients with a primary, histologically proven sBCC (n = 64) or nodular BCC (n = 64) were randomized to topical diclofenac, calcitriol, combination of both, or no topical treatment (control group). After self-application twice daily under occlusion (8 weeks), tumors were excised. Primary outcome was posttreatment expression levels of proliferation (Ki-67) and antiapoptosis (B-cell lymphoma [Bcl-2]) immunohistochemical markers. Secondary outcomes were histologic clearance, adverse events, application-site reactions, and patient compliance. RESULTS: sBCC treated with diclofenac showed a significant decrease in Ki-67 (P < .001) and Bcl-2 (P = .001), and after combination therapy for Ki-67 (P = .012). Complete histologic tumor regression was seen in 64.3% (P = .0003) of sBCC (diclofenac) and 43.8% (P = .007) of sBCC (combination therapy) compared with 0.0% of controls. No significant changes were found in nodular BCC. Application-site reactions were mostly mild to moderate. LIMITATIONS: The sample size was small. CONCLUSION: Our results suggest that topical diclofenac is a promising new treatment for sBCC. Its mode of action differs from available noninvasive therapies, and thus has an additive value.

Squamoid Eccrine Ductal Carcinoma: A Clinicopathologic Study of 30 Cases.

Squamoid eccrine ductal carcinoma is a poorly documented skin adnexal carcinoma showing squamous and duct differentiation. It is regarded to be of low-grade malignant potential, but limited follow-up information is available. To study their clinical behavior and histologic features, 30 squamoid eccrine ductal carcinomas were identified from departmental and referral files. Hematoxylin and eosin-stained sections were reviewed, and immunohistochemistry for carcinoembryonic antigen and epithelial membrane antigen was examined to confirm duct differentiation. Clinical follow-up was obtained from patient records and referring pathologists. The tumors presented as nodules or plaques (median size, 1.0 cm; range, 0.5 to 2.5 cm) with a predilection for the head and neck (77%). The patients were elderly (median age, 79.5 y; range, 10 to 96 y) with a male predominance. Histologically, these poorly demarcated tumors were characterized by an infiltrative growth pattern within the dermis and additional invasion of subcutis in 70%. Median tumor thickness was 4.3 mm (range, 1.5 to 18 mm). Superficially, the tumors resembled well-differentiated squamous cell carcinoma. In the deeper reaches, they were organized in cords and strands showing duct differentiation in a desmoplastic stroma. Cytologic atypia was moderate to severe. Ulceration (47%), necrosis (23%), and perineural and lymphovascular infiltration (27% and 6%, respectively) were additional features. Follow-up data (median, 29 mo; range, 7 to 99), available for 24 patients (80%), revealed a local recurrence rate of 25%. Three patients had lymph node metastasis, and 1 patient died of metastatic disease. Our study outlines the histologic characteristics of squamoid eccrine carcinoma and emphasizes its clinical behavior with risk for local recurrence and potential for more aggressive behavior with metastasis and rare disease-related mortality.

Morphologically low-grade spiradenocarcinoma: a clinicopathologic study of 19 cases with emphasis on outcome and MYB expression.

Spiradenocarcinoma is a rare skin adnexal neoplasm with potential for aggressive behavior, classified histologically into low- and high-grade tumors. Morphologically, low-grade tumors are thought to behave more favorably. Limited information is available, however, with only 18 published cases. To study their clinical behavior, histological features, and the diagnostic value of immunohistochemistry, 19 morphologically low-grade spiradenocarcinomas were retrieved and compared with 21 spiradenomas and cylindromas. H&E-stained sections were reviewed, follow-up was obtained, and immunohistochemistry for Ki-67, p53 and, MYB was performed. The tumors were solitary, measuring 0.8-7 cm (median: 2.7 cm), with a predilection for the head and neck of elderly patients (median age: 72 years; range 53-92) without gender bias. Histologically, the tumors were multinodular and located in deep dermis and subcutis. A pre-existing spiradenoma was present in all cases. The malignant component was characterized by expansile growth with loss of the dual cell population, up to moderate cytological atypia and increased mitotic activity (median: 10/10 HPF; range 1-28). Additional findings included squamoid differentiation (n=9), necrosis (n=7), and ulceration (n=5). P53 expression was variable and no significant differences were noted in the benign compared with the malignant parts of the tumors. In contrast, in the malignant components the Ki-67 proliferative index was slightly increased, and MYB expression was lost. Follow-up (median: 67 months; range: 13-132) available for 16 patients (84%) revealed a local recurrence rate of 19% but no metastases or disease-related mortality. In this large study with long-term follow-up, we demonstrate that spiradenocarcinomas with low-grade morphology pursue an indolent course, characterized by local recurrence only. Metastases and disease-related mortality appear to be exceptional. Lack of MYB expression may be useful as an additional aid in the diagnosis of these challenging tumors.

[A man with painful testis]. / Een man met een pijnlijke testis.

A 54-year-old man presented with intermittent pain in the left testis caused by a fibrothecoma of the testis.