David A. Mehregan

Pulsed dye laser therapy for sun damaged skin

The objective of this study was to evaluate the effectiveness of the pulsed dye laser (585 nm, 450 ms) in the treatment of sun induced wrinkles.

Carbon dioxide laser vaporization of recalcitrant symptomatic plaques of Hailey-Hailey disease and Darier's disease

Carbon dioxide laser vaporization of localized, recalcitrant intertriginous plaques was done in two patients with Hailey-Hailey disease and two patients with Dariers disease. After treatment, only one patient had recurrence in one treatment site. All patients had significant clinical and symptomatic improvement. Destructive treatment must include the follicular infundibulum in Dariers disease, because histologically this was the focus of recurrent disease at one treated site. We suggest carbon dioxide laser vaporization for the treatment of chronic, localized, symptomatic plaques of Hailey-Hailey or Dariers disease, if medical therapy has been ineffective.

Clinical and histologic evaluation of psoriatic plaques treated with a flashlamp pulsed dye laser

BACKGROUND Psoriatic plaques can be cleared by destruction of the dermal papillae. Dilated vessels, the major component of psoriatic dermal papillae, can be selectively destroyed with yellow light lasers. Previous investigators have demonstrated partial clearing of psoriatic plaques after treatment with a pulsed dye laser (PDL) (585 nm). OBJECTIVE This study was designed to examine the clinical and histologic events of psoriasis treated with the PDL. METHODS Psoriatic plaques were treated with a short (450 microseconds) and long (1500 microseconds) pulse-width PDL. Photographs of the plaques were used for clinical assessment. Biopsy specimens were examined microscopically. RESULTS Significant clinical improvement was seen, and no significant difference between the long and short pulse-width lasers was found. Patients responding to treatment with the PDL remained in remission for up to 13 months. Histologic normalization occurred after treatment. Two pretreatment vascular patterns were seen: vertically oriented vessels with few horizontal vessels and numerous tortuous vessels. Tortuous vessels were associated with poor clinical results. CONCLUSION The PDL can induce prolonged remission in chronic plaque psoriasis. The vascular pattern may help to distinguish those patients likely to respond to this treatment.

Subcutaneous T‐cell lymphoma: A clinical, histopathologic, and immunohistochemical study of six cases

Recently, T‐cell lymphoma localized to the subcutaneous tissue has been reported. We report the clinical, histolpgic, immunohistochemical, and molecular genetic findings in 6 patients who we believe had this peculiar T‐cell lymphoma with its unique morphologic and clinical features. All patients presented with deep‐seated nodules, most frequently on the extremities, and with systemic complaints of low‐grade fever, fatigue, myalgias, and weight loss. In all cases, the neoplastic lymphocytic infiltrate was confined to the subcutaneous tissue, predominantly in a lobular pattern. Hemorrhage, necrosis, and rare erythrophagocytosis were also seen. Immunohistochemical staining was predominantly T‐cell reactive (CD43, CD3, and CD45RO). Clonal rearrangements of the β and γ chains of the T‐cell antigen receptor genes were found in 1 case. Three of the 6 patients died within 22 months of the diagnosis of lymphoma. We believe that subcutaneous T‐cell lymphomas are a distinctive group of peripheral T‐cell lymphomas with unusual clinical and morphologic features and that they should be distinguished from other types of lymphoma.

Deep penetrating nevus

BACKGROUND Deep penetrating nevus is a variant of melanocytic nevi with histologic features that may be alarming and can be mistaken for malignant melanoma. We are presenting a review of the clinical findings and the histologic features of deep penetrating nevus in a series of 14 cases. OBSERVATIONS Deep penetrating nevus occurs most commonly over the acral skin of young adults. Clinically, the lesions were diagnosed as pigmented nevus, blue nevus, or malignant melanoma. Histologically, deep penetrating nevus shows a wedge-shaped lesion extending to the deep dermis and the subcutaneous fat tissue. Nests and fascicles of pigmented melanocytes extended deep at the periphery of blood vessels, nerves, and the cutaneous adnexa. Low-grade cellular atypia is present and mitoses are rare. CONCLUSIONS Deep penetrating nevus is a variant of benign pigmented nevi with deep dermal and subcutaneous involvement. The pattern should be recognized and differentiated from malignant melanoma.

Chronic Lupoid Leishmaniasis: Evaluation by Polymerase Chain Reaction

BACKGROUND The cutaneous lesions in chronic lupoid leishmaniasis resemble those of lupus vulgaris, both clinically and histologically. The differential diagnosis is difficult and may depend on the detection of a few Leishmania amastigotes in the histologic sections, the growth of the promastigotes in cultures, or the identification of amastigotes by other techniques. Polymerase chain reaction was used to detect Leishmania amastigote DNA in tissue samples obtained from 65 patients with chronic lupoid leismaniasis, and the results were confirmed by Southern blot analysis. OBSERVATIONS The histologic findings of a predominantly epithelioid cell granuloma surrounded by lymphocytic infiltrate in chronic lupoid leishmaniasis are very similar to those observed in lupus vulgaris. Extensive histologic examination of the sections in this series revealed occasional macrophages containing a few amastigotes in only 12 cases. Cultures in NNN medium yielded Leishmania promastigotes in 20 cases. Polymerase chain reaction studies using a Leishmania-specific primer identified Leishmania DNA in 30 of 63 cases, and those using a Mycobacterium tuberculosis primer were found to be negative for mycobacteria in 47 cases tested, including 11 cases with a positive tuberculin skin reaction. CONCLUSIONS The histologic findings in chronic lupoid leishmaniasis resemble those of lupus vulgaris. Polymerase chain reaction studies were useful in identifying amastigotes in 30 (47.6%) of 63 cases. This study confirms the presence of DNA molecules of Leishmania amastigotes in samples of formalin-fixed, paraffin-embedded granulomatous tissue obtained from patients with chronic lupoid leishmaniasis.

Malignant blue nevus: a report of eight cases

Malignant blue nevus is uncommon compared to its benign counterpart and is regarded as a rare form of malignant melanoma. We report the clinical and histological findings in eight cases. Histologically, all eight specimens showed no epidermal involvement and had contained within or were adjacent to portions of blue nevus or cellular blue nevus. Proliferation of bundles of bipolar spindle shaped cells with marked cellular atypia, mitotic figures, foci of necrosis, and inflammatory cell infiltrate were noted. Two of the cases were studied by DNA flow cytometry and the populations of tumor cells were found to be diploid. Two cases have died secondary to metastasis. Although malignant blue nevi may not behave as aggressively as nodular malignant melanoma, they have definite potential to do so and therefore should be removed by wide surgical excision.

Intertriginous granular parakeratosis

An unusual form of parakeratosis localized to the axillae has been previously described in the literature as axillary granular parakeratosis. We report an additional 4 cases, including one that was isolated to the inguinal region. The same histopathologic changes of papillomatosis, acanthosis, and parakeratosis with retention of keratohyalin granules were found in all 4 cases. In the future, we suggest that this entity be designated as intertriginous granular parakeratosis to reflect the newly recognized pattern of distribution. Three separate reports1-3 have described 8 cases of a distinct cutaneous condition known as axillary granular parakeratosis. We describe an additional 4 cases, including the first documented case outside of the axillae (ie, within the groin).

Axillary granular parakeratosis

We report two cases of axillary granular parakeratosis, which is a unique eruption involving the axilla that has distinctive histopathologic features. Both of our patients had slightly pruritic, hyperpigmented patches in the axilla. The biopsy specimens revealed severe compact parakeratosis with maintenance of the stratum granulosum and retention of keratohyalin granules throughout the stratum corneum, which was markedly thickened and measured between 90 to 185 microns. The exact etiology is not known, but this conditions is believed to represent a contact reaction to an antiperspirant or deodorant.

Histopathologic Study of Hidradenitis Suppurativa Following Long-Pulsed 1064-nm Nd:YAG Laser Treatment

OBJECTIVE To assess clinical and histopathologic changes occurring after long-pulsed 1064-nm Nd:YAG laser treatment of hidradenitis suppurativa (HS). DESIGN Prospective, controlled clinical and histologic study of patients with Hurley stage II HS disease. SETTING Outpatient dermatology department at Henry Ford Hospital, Detroit, Michigan. PARTICIPANTS Nineteen patients with Fitzpatrick skin types II to VI with Hurley stage II HS lesions of the axilla and groin. Interventions Two monthly laser sessions were performed using the long-pulsed 1064-nm Nd:YAG laser. Main Outcome Measure Clinical response was scored using the modified Sartorius scale for HS reflecting Lesion Area and Severity Index (LASI). Histologic changes were examined before treatment and 1 week, 1 month, and 2 months after treatment. RESULTS The percentage change in HS severity after 2 sessions of laser treatment was -31.6 over all anatomic sites (P < .005), -24.4 for the axillary site (P = .008), and -36.8 for the inguinal site (P = .001). Histologic changes corresponded to clinical response. Findings from serial biopsy specimens showed increased inflammation at 1 week after treatment and decreased inflammation with resulting fibrosis and scarring at 1 month and 2 months after treatment. CONCLUSIONS The long-pulsed 1064-nm Nd:YAG laser is a novel effective treatment option for HS. Our histopathologic data suggest that HS is primarily a follicular disorder. The Nd:YAG laser penetrates for selective photothermolysis of the follicular unit and destruction of organized inflammatory lesions in the superficial to mid dermis. Our study offers insight into the pathogenesis of HS and the mechanism of the Nd:YAG laser in treatment of patients with this chronic, debilitating disease.