Invasive penile squamous cell carcinoma.

Invasive penile squamous cell carcinoma (PSCC) is a rare malignancy with considerable morbidity and mortality. Because a delayed or incorrect diagnosis can have a devastating outcome, physicians should maintain a high index of clinical suspicion for PSCC in patients presenting with penile lesions, particularly in young or middle-aged patients in whom presentation of PSCC is uncommon. We report the case of a 27-year-old circumcised man who presented with invasive PSCC following a diagnosis of condyloma 8 years prior. The patient underwent robotic laparoscopic bilateral pelvis and inguinal lymph node dissection and re-excision of the primary PSCC, with one of 15 superficial right inguinal lymph nodes testing positive for squamous cell carcinoma. Given the patient's single-node positivity as well as the risks associated with chemotherapy with respect to his concurrent medical conditions, close follow-up with repeat imaging was planned following surgery. This case highlights the importance of biopsy in any lesion recalcitrant to conventional treatment modalities regardless of age. Early detection and treatment of PSCC can prevent organ dysfunction, loss of organ, or even death.

Statistical analysis of the concordance of immunohistochemical stains with the final diagnosis in spitzoid neoplasms.

INTRODUCTION: The classification of spitzoid melanocytic tumors can be difficult, and pathologists rely on both histological features and clinical information to arrive at a diagnosis. We proposed that an immunohistochemical panel could be useful in classifying these neoplasms and designed a study to test the independent contribution of the panel to the final diagnosis. METHODS: We identified 121 cases previously signed out either as (1) Spitz nevus, (2) atypical spitzoid neoplasm, favor Spitz nevus, (3) atypical spitzoid neoplasm of uncertain malignant potential, (4) atypical spitzoid neoplasm, favor melanoma, and (5) spitzoid melanoma. The slides were reveiwed in random order by 4 pathologists. For the first review, the pathologists received only hematoxylin and eosin sections and patient age. Subsequently, the same pathologists interpreted the immunohistochemically stained slides (S-100A6, HMB-45, and MIB-1) on the same cases in randomized order without the benefit of either hematoxylin and eosin sections or patient age. The original diagnosis (based on a combination of clinical information, hematoxylin and eosin-stained sections and immunohistochemical stains) was the gold standard used for statistical analysis. The primary aim of the study was to determine the level of agreement between interpretions based on hematoxylin and eosin sections and age, the immunostains alone, and the gold standard, thus providing a measurement of the degree to which each of these elements contributes to the final diagnosis. The agreement between the gold standard and external review was also determined for those cases sent for external review. RESULTS: The generalized kappa statistic was 0.95 for both the hematoxylin and eosin-stained slides alone and the immunohistochemical stains alone, implying a high level of agreement among the 4 pathologists. The combined weighted kappa statistic for the comparison of hematoxylin and eosin sections and patient age to the gold standard was 0.49, and for the immunohistochemically stained slides to the gold standard 0.48, indicating that a diagnosis based on hematoxylin and eosin sections alone or immunostains alone show only a moderate and similar level of agreement with the gold standard diagnosis. Only the most controversial cases were sent for external review. The weighted kappa statistic estimate was 0.30 for the gold standard diagnosis on those cases and the external review. CONCLUSIONS: Spitzoid neoplasms remain a difficult area in dermatopathology and experts frequently disagree on the most challenging cases. An immunohistochemical panel contributes to the diagnosis of spitzoid tumors, and the contribution is statistically similar to that of hematoxylin and eosin sections and age. Interpretation remains subjective, as evidenced by the comparison of the gold standard and external review.

The staining pattern of pigmented spindle cell nevi with S100A6 protein.

BACKGROUND: Spitz nevi typically show strong diffuse staining with S100A6, whereas staining in melanomas is commonly patchy and weak. To our knowledge, S100A6 has not been studied in pigmented spindle cell nevus (PSCN), considered by many to be a variant of Spitz nevus. METHODS: Forty-six archived PSCNs were stained with S100A6 and then categorized by predominant cell size and staining pattern. RESULTS: Eighteen (55%) of the small cell predominant nevi showed patchy staining, eight showed diffuse staining and seven were negative for S100A6. Two predominantly large-celled 'PSCNs' were diffusely positive and had many histopathological attributes of classical Spitz nevi. On review, these two cases were reclassified as Spitz nevi and excluded from the remainder of this study. Of the nevi with mixed cell size, one had no expression of S100A6. In the remaining tumors, the small cells showed patchy staining in eight (80%) and diffuse staining in two (20%). The large cells showed patchy staining in four (40%) and diffuse staining in six (60%). CONCLUSION: In contrast to the strong diffuse S100A6 staining typical of Spitz nevi, the small spindle cells of PSCN commonly show patchy staining or fail to stain completely. In melanocytic neoplasms composed of small spindle cells, patchy S100A6 staining should not be interpreted as evidence of supporting a diagnosis of melanoma.

Dense lymphocytic infiltrates associated with non-melanoma skin cancer in patients with chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is a common hematologic malignancy associated with an increased risk of non-melanoma skin cancer. Basal cell carcinomas and squamous cell carcinomas in these patients may have an associated dense peritumoral leukemic infiltrate. This infiltrate can lead to the diagnosis of CLL and may also obscure tumor margins and pose a challenge in the assessment of perineural tumor spread. Immunohistochemical stains are useful in distinguishing leukemic B-cell infiltrates from tumor-reactive T-cell infiltrates. Leukemic cells of CLL are CD20+/CD23+/CD5+/CD43+/CD3-, whereas benign reactive infiltrates are composed of CD20-/CD23-/CD5+/CD43+/CD3+ T-cells. Given the paucity of symptoms in early stages of CLL, a dense lymphoid infiltrate surrounding a cutaneous neoplasm may serve as the first indication of CLL. We report a series of three cases of SCC with a coexisting infiltrate of CLL, including one with perineural involvement, one involving metastatic SCC, and one in which this histologic finding spurred the initial diagnosis of CLL.

Neurofibroma with clear cell change.

Cutaneous clear cell proliferations and degenerative change have been seen in a variety of entities including nevi, dermatofibromas, fibrous papules, atypical fibroxanthomas, basal cell carcinomas, and squamous cell carcinomas, to name a few. However, there have been no reports of clear cells within neurofibromas. We received a biopsy and excision from a 61-year-old man with a papule on his right lateral clavicle. The initial biopsy showed a proliferation of clear cells that stained positive with S-100 and focally with CD68. A clear cell granular cell tumor was favored. Subsequent excision showed the same population of clear cells as seen on the initial biopsy. Interestingly, a neurofibroma was also present immediately beneath the clear cells with areas of transition. A p75 stain highlighted both populations of cells. This is the first case of neurofibroma with clear cells reported in the literature. We postulate that the clear cells are due to degenerative change.

Fontana-positive grains in mycetoma caused by Microsporum canis.

We describe mycetoma caused by Microsporum canis occurring in a 9-year-old African-American girl. Pathologic evaluation showed a granulomatous dermatitis with numerous large fungal grains containing septate hyphae that were Fontana-Masson positive. Two cultures of pure grains grew M. canis. Mycetoma due to dermatophytes is very uncommon. The few instances reported have been pseudomycetoma (grains in the absence of sinus tracts). Our patient developed sinus tracts (true mycetoma). No prior reports were found of M. canis staining Fontana positive. Differentiation of dermatophyte-induced mycetoma from kerion is important because mycetomas require a combined approach including surgical debridement in addition to oral antifungal therapy.

Mycobacterium haemophilum in an immunosuppressed child.

Mycobacterium haemophilum is an emerging cutaneous and systemic pathogen in immunosuppressed adults. Reports in the pediatric literature prior to 2004, limited to immunocompetent children with lymphadenitis, offer a different clinical presentation from that of the immunosuppressed adult. We report an instance of this atypical mycobacterial infection occurring in an immunosuppressed boy with clinical findings similar to those described in immunosuppressed adults.

Kaposi's varicelliform eruption: a case report and review of the literature.

Disseminated herpes or vaccinia in the setting of underlying skin diseases is known as Kaposi's varicelliform eruption (KVE). Patients typically present with disseminated vesicopustules in the areas of the most severe involvement of their underlying skin disease. We report a case of eczema herpeticum in a woman with a long-standing history of atopic dermatitis (AD). This report also reviews the literature on eczema herpeticum and eczema vaccinatum (EV), summarizes clinical and histopathologic characteristics and treatment, and discusses the recommendations of the Centers for Disease Control and Prevention for smallpox vaccination.

Persistent cellulitis in a patient receiving renal dialysis.

Cryptococcus neoformans, an opportunistic fungus, may cause cutaneous disease by dissemination from primary lung infection or, more rarely, by direct cutaneous inoculation. Cellulitis in an immunocompromised host who does not respond to conventional antibacterial therapy should alert the physician to consider other diagnoses, including cryptococcal skin infection.

Worsening injection site reactions with continued use of etanercept.

We report the case of a patient with persistent and worsening injection site reactions associated with subcutaneous etanercept therapy. Injection site reactions are well documented to occur early in therapy; however they typically decrease in frequency over time. This patient developed early injection site reactions that have persisted and worsened into his tenth month of treatment with etanercept.

Interdigital pilonidal sinus in a dog groomer.

Pilonidal sinus is an acquired condition that usually develops in the sacrococcygeal area or other hair-bearing areas. It has also been described as an occupational disease, especially when present interdigitally. We describe the case of a 47-year-old dog groomer with interdigital pilonidal sinus and briefly review the postulated pathogenesis, clinical characteristics, differential diagnosis, and treatment.

Lentigo maligna with spread onto oral mucosa.

BACKGROUND: Lentigo maligna (LM) is a form of melanoma in situ most often seen in white patients on sun-exposed areas, primarily the head and neck. Spread of LM onto the conjunctiva has been reported. There have been no reports of LM extending onto oral mucosa. OBSERVATIONS: We report 4 cases of LM in white women with contiguous spread from perioral areas to oral mucosa. The locations of the primary lesions were the vermilion of the lip, vermilion and perioral skin, cheek, and cutaneous aspect of the lip. Three cases showed focal histopathologic evidence of invasion during the course of the disease. The lesions ran a prolonged course characterized by repeated recurrences after surgery. Three of the cases required a complicated reconstruction after surgical excision. Mohs surgery with rush permanent (paraffin-embedded) sections resulted in a long remission in 2 cases, while in 1 patient, treatment with carbon dioxide laser was unsuccessful. CONCLUSIONS: In a perioral distribution, LM can spread onto oral mucosa. This clinical presentation may cause significant long-term morbidity, as indicated by a high recurrence rate and/or progression to invasive melanoma. The oral mucosa should be examined in patients with atypical pigmented perioral lesions.

Eccrine angiomatous hamartoma.

Four patients with eccrine angiomatous hamartoma are described. Blue-purple color, enlarging size, location on an extremity, pain, and hypertrichosis were common features and aided differentiation from other vascular anomalies and hamartomas of childhood. None of our patients experienced lesional hyperhidrosis, and simple excision alleviated pain.