Imiquimod-induced hypertrophic lupus erythematosus-like reaction.

Imiquimod is a topical immunomodulator that acts as an inducer of interferon (IFN)-a expression through Toll-like receptor (TLR)7 signaling with indications for the treatment of non-hyperkeratotic actinic keratosis of the face or scalp, superficial basal cell carcinoma (BCC), and external genital and perianal warts. Imiquimod is also used off-label for nodular BCC, cutaneous T-cell lymphoma, pyogenic granuloma, and melanoma. Imiquimod-induced lupus-like reactions have been reported. However, hypertrophic lupus erythematosus (HLE) is a rare variant of cutaneous lupus and imiquimod-induced hypertrophic lupus has not been reported to date. We report a case of local induction of a plaque that resembled HLE clinically and histologically in an 82-year old woman following topical treatment with imiquimod.

Peritoneal mesothelioma presenting as a skin nodule.

Mesothelioma is a malignancy of the pleura, pericardium and peritoneum that is rarely seen in cutaneous biopsies. We present a case of a 75-year-old man with significant occupational exposure to asbestos who developed peritoneal mesothelioma that presented as a skin nodule in an old appendectomy scar. The patient presented with a complaint of increased hardness along his appendectomy scar. Physical examination revealed an anterior abdominal wall mass overlying the appendectomy scar, which was subsequently biopsied. Histologic examination of the abdominal wall mass revealed an infiltrating epithelioid and papillary neoplasm within the dermis and subcutaneous tissue. Immunohistochemical stains showed immunoreactivity for cytokeratin (CK) 7, CK 5/6, calretinin and vimentin. CK 20, monoclonal carcinoembryonic antigen, prostate-specific antigen and prostate-specific acid phosphatase were negative. The profile supported the diagnosis of mesothelioma. Cutaneous presentation of mesothelioma is rare but should be considered in the differential diagnosis of patients with significant asbestos exposure.

Metastatic myoepithelial carcinoma in a child.

Cutaneous myoepithelial tumors are rare entities, with few reported malignant variants in the literature. The majority of these tumors are reported in the head and neck region of the adult population, with few examples in the literature arising in young patients. We present a case of myoepithelial carcinoma in a 13-year-old girl, with documented metastatic disease. Reproducible predictors of malignant behavior have yet to be clarified.

Unilesional mycosis fungoides mimicking Bowen's disease.

Cutaneous T-cell lymphoma includes a heterogeneous group of lymphomas that share the unique feature of T lymphocytes which are tropic to the skin. Clinically, the presentation of this disease is protean and can range from a single lesion to generalized erythroderma. Unilesional mycosis fungoides, a rare variant, is presented here. Its morphology mimicked squamous cell carcinoma in situ, and was refractory to conventional therapies. A review of the treatment of this subset is also presented.

Solitary fibrous tumors in the central nervous system. A clinicopathologic review of 18 cases and comparison to meningeal hemangiopericytomas.

CONTEXT: Solitary fibrous tumors (SFTs) of the central nervous system are rare neoplasms that usually present as dura-based masses and clinically resemble meningiomas. Histologically, they can be similar to fibrous meningioma or hemangiopericytoma (HPC). In particular, densely cellular regions seen in some SFTs can be indistinguishable from HPC. Little is known about the biological behavior of SFTs, although most seem amenable to total resection. OBJECTIVES: To define the clinicopathologic spectrum of SFTs in the central nervous system and to outline their differences from HPC and meningioma. DESIGN: We present the clinicopathologic features of 18 patients with SFT and compare them with those of an age- and sex-matched cohort of HPCs. RESULTS: Eleven SFTs were supratentorial, 3 were infratentorial, and 4 were intraspinal. Four of the 18 tumors were intra-axial (2 in the lateral ventricles and 2 within the spinal cord). Histologically, SFTs were similar to their soft tissue counterparts. Six tumors (6/18) had densely cellular regions, and 1 tumor showed frankly anaplastic features. All but 3 patients underwent gross total resection, and there were no metastases or tumor-related mortalities during the median follow-up of 40 months. In contrast, there were 15 local recurrences (83%), 5 extracranial metastases (27%), and 4 tumor-related deaths (22%) in the HPC cohort. CONCLUSIONS: Our study presents the clinicopathologic features of SFT as a distinct entity from both meningioma and HPC. We also present unusual examples of anaplastic, intraventricular, and intramedullary spinal SFTs that expand the clinicopathologic spectrum of these uncommon and sometimes diagnostically difficult neoplasms.

Multicentric parenchymal xanthogranuloma in a child: case report and review of the literature.

OBJECTIVE AND IMPORTANCE: Xanthogranulomas of the central nervous system are rare, and asymptomatic lesions are often identified in autopsies. We report the first case of a multicentric, cystic, intraparenchymal xanthogranuloma, involving both the supra- and infratentorial compartments, in a 16-month-old girl. CLINICAL PRESENTATION: The clinical presentation consisted of a focal motor seizure in an otherwise healthy infant. INTERVENTION: Gross total removal of the infratentorial lesion was accomplished via a midline suboccipital craniotomy. CONCLUSION: Intracranial xanthogranulomas are rare, and limited experience with the diagnosis of these lesions has been reported. Although most cases are asymptomatic, this case involves a symptomatic, multicentric, intraparenchymal xanthoma in a pediatric patient. Our review of the literature provides further insights regarding the clinical, radiological, and pathological behavior of these lesions and examines the available treatment strategies.

Should the diagnosis of benign prostatic hyperplasia be made on prostate needle biopsy?

Pathologists frequently sign out benign prostate needle biopsies as "benign prostatic hyperplasia (BPH)". There are no data indicating that a diagnosis of BPH on biopsy correlates with either gland weight or with the International Prostate Symptom Score (IPSS) used to measure urinary obstructive symptoms. We examined biopsies for average percentage of glands and average percentage of glands with papillary infolding per case, maximum percentage of glands and maximum percentage of glands with papillary infolding per core per case, and presence of any stromal nodules per case. BPH was measured in 2 ways: (1) IPSS grouped into 3 categories (mild, moderate, severe) and (2) prostate weight at radical prostatectomy in men with limited cancer. IPSS was classified as follows: mild (n = 12), moderate (n = 13), and severe (n = 10). There was no correlation with IPSS and any of the histologic features measured. For the 41 radical prostatectomy specimens, the average weight was 65.3 g (median, 56.0 g, range, 22 to 117 g). There was no correlation between gland weight and the average or maximum percentage of glands, or average or maximum percentage of glands with papillary infolding. Stromal nodules on biopsy correlated with gland weight. In the 30 cases without stromal nodules on biopsy, the mean gland weight was 51.4 g. In the 11 cases with stromal nodules on biopsy, the mean gland weight was 77.4 g (P = 0.0125). However, stromal nodules were not specific for a large prostate (i.e., a 15 g prostate had stromal nodules on biopsy). With the exception of stromal nodules found on biopsy, histologic findings on biopsy are not specific for either clinical or pathologic BPH. Thus benign prostate biopsies should be signed out merely as "benign prostate tissue."