Pseudocarcinomatous hyperplasia with follicular differentiation overlying basal cell carcinoma.

We present a series of 25 cases of basal cell carcinoma (BCC) with overlying cytologically bland epidermal hyperplasia and cyst formation. Eight of the BCCs were nodular and 11 were infiltrative. Immunohistochemical staining for Ki-67 and cytokeratin 17 (CK17) was performed to evaluate the proliferative and differentiation characteristics of the hyperplastic epithelium compared with the adjacent BCC and normal epidermis. Fourteen of the 25 cases had sufficient tissue to evaluate the staining patterns. In the majority of cases, Ki-67 expression was prominent throughout the BCCs, but only expressed in the basal and suprabasal layers of the adjacent hyperplastic epithelium, which was equivalent to normal epidermis. CK17 expression was prominent throughout the BCC and surrounding incident hair follicles. CK17 was expressed to a lesser extent in the central more keratinized portions of the hyperplastic epithelium, but rarely in normal epidermis. The morphologic characteristics and immunohistochemical staining patterns in these tumors suggest that the epidermal hyperplasia represents pseudocarcinomatous hyperplasia with follicular differentiation. Recognizing this pattern of epidermal change should alert the pathologist to the possibility of an associated BCC in cases in which the biopsy specimen or sectioning is initially too superficial to reveal the underlying malignancy.

The inadequacy of punch-excised melanocytic lesions: sampling through the block for the determination of "margins".

BACKGROUND: Dermatopathologists often are asked by clinicians to report margins on punch excisions of melanocytic lesions. OBJECTIVE: We sought to determine the adequacy of surgical margins on melanocytic lesions submitted with intention of complete excision using punch removal technique. METHODS: We conducted prospective analysis of surgical margins on 266 consecutive patients who underwent attempted complete removal of 405 melanocytic nevi submitted as punch and fusiform excisions. RESULTS: Of 206 nonbisected punch excisions, 127 (62%) had final positive margins. Of 159 bisected punch excisions, 76 (48%) had final positive margins. Of 40 elliptical excisions, two (5%) had final positive margins. LIMITATIONS: Information on the perilesional rim of nonpigmented skin included in the excision was not available. CONCLUSIONS: Of punch excisions, 56% had positive margins. Importantly, 30% of these punch excised specimens were negative on initial levels but had positive margins after extensive sectioning, affirming that fusiform excisions are the preferred method to evaluate margins in melanocytic lesions.

The effects of laser irradiation on Trichophyton rubrum growth.

The effects of various laser wavelengths and fluences on the fungal isolate, Trichophyton rubrum, were examined in vitro. Standard-size isolates of T. rubrum were irradiated by using various laser systems. Colony areas were compared for growth inhibition on days 1, 3, and 6 after laser irradiation. Statistically significant growth inhibition of T. rubrum was detected in colonies treated with the 1,064-nm Q-switched Nd:YAG laser at 4 and 8 J/cm(2) and 532-nm Q-switched Nd:YAG laser at 8 J/cm(2). Q-switched Nd:YAG laser at 532- and 1,064-nm wavelengths produced significant inhibitory effect upon the fungal isolate T. rubrum in this in vitro study. However, more in vitro and in vivo studies are necessary to investigate if lasers would have a potential use in the treatment of fungal infections of skin and its adnexa.

Low-grade fibromyxoid sarcoma presenting clinically as a primary ovarian neoplasm: a case report.

Low-grade fibromyxoid sarcoma is an uncommon, deceptively bland mesenchymal neoplasm that typically occurs in the deep soft tissues of the proximal extremities of young to middle-aged patients. Intra-abdominal low-grade fibromyxoid sarcomas are distinctly rare. We describe the first reported example of this sarcoma involving the ovary. The 42-year-old patient presented with progressing abdominal pain and urinary frequency. Computed tomographic imaging of the abdomen and pelvis showed a 14-cm left-sided pelvic mass. The patient underwent surgical resection and, intraoperatively, a left ovarian mass was identified that extended to both the left hypogastric artery and the left ureter. The resected specimen consisted of a 17-cm tan, fleshy mass containing grossly recognizable nodules of gelatinous, myxoid tissue and a small rim of normal ovary. Microscopic examination of the neoplasm revealed a cytologically bland spindle cell proliferation set in a collagenized stroma that abruptly transitioned to nodules of a myxoid stroma with a well-formed capillary vasculature, features characteristic of low-grade fibromyxoid sarcoma. On the basis of the diagnosis, the patient was clinically staged as a retroperitoneal sarcoma with secondary ovarian involvement. The patient has stable residual disease 11 months postoperatively. This case adds to the literature of intra-abdominal low-grade fibromyxoid sarcoma and expands the list of malignant mesenchymal neoplasms that may involve the ovary.

Monophasic sarcomatoid carcinoma of the scalp: a case mimicking inflammatory myofibroblastic tumor and a review of cutaneous spindle cell tumors with myofibroblastic differentiation.

BACKGROUND: The evaluation of malignant cutaneous spindle cell tumors is challenged by a diagnostic differential that comprises neoplasms of diverse histogenesis, and a broad immunohistochemical panel may confound the diagnosis when the results suggest multiple lines of differentiation, such as with a combined myofibroblastic and epithelial phenotype. METHODS: We report the case of a solitary scalp nodule that quickly became locally metastatic. A comprehensive panel of immunohistochemistry markers and electron microscopy was evaluated to determine the differentiation of the spindle cells. RESULTS: The tumor, consisting of wavy and slender spindle cells with predominantly bland nuclei, showed immunoreactivity to vimentin, smooth muscle actin, and muscle-specific actin. AE1/AE3, CK5/6, and MNF-116 antibodies were weakly positive in rare cells. However, 34betaE12 showed diffuse positivity in the spindle cell population, thus supporting the diagnosis of a sarcomatoid carcinoma with myofibroblastic differentiation. CONCLUSIONS: The use of 34betaE12 is essential for the evaluation of myofibroblastic spindle cell tumors with rare cytokeratin reactivity. However, even with immunohistochemical and electron microscopic studies, the diagnosis of spindle cell tumors can be confounded by the multiplicity of nosologic equivalents, such as carcinosarcoma, spindle cell carcinoma, and metaplastic carcinoma. The nomenclature of these spindle cell tumors is discussed.