Kikuchi-Fujimoto Disease With Unusual Cutaneous Findings.

ABSTRACT: We present a case of the rare Kikuchi-Fujimoto disease (KFD) in a 14-year-old patient admitted to UCLA Medical Center with fever, weight loss, and pancytopenia. Physical examination revealed tender subcutaneous nodules and cervical lymphadenopathy. A lymph node biopsy showed findings consistent with KFD. The skin biopsy showed mild superficial dermal edema with neutrophil-predominant inflammation. In addition, rare atypical monocytoid cells were seen. This histologic finding of a Sweet-like morphology has not been reported previously in the literature in association with KFD. The differential diagnosis included Sweet syndrome arising in association with KFD, underlying connective tissue, and an infectious etiology.

Kaposi sarcoma in anti-neutrophil cytoplasmic antibody-associated vasculitis: a case-based review.

Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) are systemic necrotizing vasculitides associated with significant morbidity and mortality. Given the immunosuppression used to manage these conditions, it is important for clinicians to recognize complications, especially infectious ones, which may arise during treatment. Kaposi sarcoma (KS) is a lymphoangioproliferative neoplasm caused by human herpes virus 8 (HHV-8). Its cutaneous manifestations can mimic vasculitis. We describe a 77-year-old man with microscopic polyangiitis with pulmonary-renal syndrome treated with prednisone and intravenous cyclophosphamide who developed KS (HHV-8 positive) after 2 months of treatment. Cyclophosphamide was discontinued and prednisone gradually lowered with improvement and clinical stabilization of KS lesions. This comprehensive review includes all published cases of KS in patients with AAV, with a goal to summarize potential risk factors including the clinical characteristics of vasculitis, treatment and outcomes of patients with this rare complication of immunosuppressive therapy. We also expanded our literature review to KS in other forms of systemic vasculitis. Our case-based review emphasizes the importance of considering infectious complications of immunosuppressive therapy, especially glucocorticoids, and highlights the rare association of KS in systemic vasculitis.

A Case of Atypical Lymphocytic Lobular Panniculitis.

Atypical lymphocytic lobular panniculitis (ALLP) is a rare T-cell dyscrasia of the subcutaneous fat. It typically presents with indurated erythematous nodules on the lower extremities and often will have a relapsing and remitting course. The cause is unknown, but clinically and histopathologically it shares similarities to lupus panniculitis (LP) and subcutaneous panniculitis-like T-cell lymphoma (SPTCL). It generally has an indolent course, and may best be treated like indolent versions of SPTCL with systemic steroids and immunosuppressive medications.

Twenty-year-old woman presenting with typical Kawasaki disease.

We describe adult-onset Kawasaki disease (KD) and review clinical manifestations and treatment guidelines. Our patient is a 20-year-old female who initially presented to an outside hospital for fever, cervical lymphadenopathy, malaise, exudative tonsillitis, and skin eruption. She received antibiotics for suspected exudative pharyngitis, but experienced continued fevers and presented to the UCLA emergency room one week later. She had diffuse petechial macules coalescing into reticulated patches, fingertip peeling, conjunctival injection, oral erosions, and tongue swelling. Despite her age, given her constellation of symptoms, a diagnosis of typical KD was favored. She was started on high dose aspirin and IVIG, with improvement of rash and conjunctivitis. She was discharged on 325mg of aspirin daily with close follow-up. This case highlights the challenge of diagnosing KD in adults. Although this patient had classic symptoms, she was likely misdiagnosed because KD is rare in adults and without validated criteria. Our patient met the pediatric criteria, suggesting these should be considered when clinical suspicion for adult-onset KD is high. Adult-onset KD is most commonly misdiagnosed as toxic shock syndrome or drug-induced hypersensitivity syndrome and these are important to rule-out. Treatment with high-dose aspirin and IVIG is well established and should be initiated promptly.

Malignant melanoma with neural differentiation: an exceptional case report and brief review of the pertinent literature.

: The term neurotropic melanoma has been used to refer to malignant melanoma with associated infiltration of nerve or "neural differentiation"--that is, melanoma cells exhibiting cytological characteristics of nerve cells. Historically, neurotropic melanoma has generally been discussed within the context of desmoplastic melanoma. We report an exceptional case of melanoma notable for a very well-differentiated neural component that was contiguous with obvious overlying melanoma. After careful consideration of all pertinent histological features, the overall diagnostic impression was that of melanoma with associated "malignant neurotization." We have not encountered a previously reported case with such a well-differentiated neural component. The following article details our exceptional case of melanoma with "malignant neurotization" and presents a discussion of the differential diagnosis and brief review of the pertinent literature.

Acquired perforating dermatosis associated with metastatic colon cancer.

Acquired perforating dermatosis (APD) is a type of perforating disorder that is traditionally thought to be associated with diabetes, chronic renal failure, or occasionally liver disease. We report a case of APD in a patient with stage IV colon cancer with hepatic metastases. Although rare, APD associated with colon cancer is an important entity to consider; APD may be associated with a broader range of systemic diseases than previously recognized.

Dyshidrotic mycosis fungoides.

Mycosis fungoides (MF) represents the most common type of cutaneous T-cell lymphoma (CTCL). CTCL often progresses through patch, plaque and tumor stages but can also manifest with varied clinical presentations. MF rarely presents in vesiculobullous fashion, in which vesicles or bullae develop in pre-existing plaques or on the trunk or proximal extremities. We report a patient who presented with a vesiculobullous eruption on the palms and soles, resembling dyshidrotic dermatitis, which we believe represents dyshidrotic MF.

Fungal leukocytoclastic vasculitis as a presentation of systemic vasculitis in a patient with systemic lupus erythematosus.

Patients with systemic lupus erythematosus (SLE) commonly have vasculitis with cutaneous involvement. Disease activity associated with SLE is frequently responsible for the vasculitis, although infection is also important to consider. We describe a young woman with SLE who was found to have leukocytoclastic vasculitis due to Candida albicans.

Immunohistochemical characteristics of melanoma.

Melanoma has a wide spectrum of histologic features which mimic epithelial, hematologic, mesenchymal, and neural tumors. Immunohistochemistry has been the primary tool to distinguish melanomas from these other tumors; it has also been studied for use as an adjunct to distinguish benign and malignant melanocytic tumors and to elucidate prognosis. Furthermore, there has been extensive effort to find a suitable marker to differentiate spindle cell and desmoplastic melanoma from other tumors. We have reviewed the literature investigating melanocytic differentiation markers, proliferation markers, immunomodulatory markers, signaling molecules, and nerve growth factors and receptors. Despite the proliferation of immunohistochemical markers, S-100 remains the most sensitive marker for melanocytic lesions, while markers such as HMB-45, MART-1/Melan-A, tyrosinase, and MITF demonstrate relatively good specificity but not as good sensitivity as S-100. No marker has proven useful in distinguishing spindle cell and desmoplastic melanomas from other tumors. Ki67 remains the most useful adjunct in distinguishing benign from malignant melanocytic tumors. None of the markers reviewed has been shown conclusively to have prognostic value for melanocytic neoplasms.

Pathologic reporting and special diagnostic techniques for melanoma.

Pathologists play a central role in the management of cutaneous melanoma in determining that a tumor is a melanoma, whether or not it is primary or metastatic, and whether or not the margins of excision are tumor free and in evaluating prognostic indicators from examination of the primary tumor and, where appropriate, lymph nodes, including the sentinel nodes.

Longitudinal melanonychia of the toenails with presence of Medlar bodies on biopsy.

A 9-year-old girl presented with a 2-year history of pigmented streaks on her second right toenail as well as on her fourth and fifth left toenails. The patient was otherwise asymptomatic with no other physical findings. Owing to parental concern, a biopsy was performed, which revealed numerous bacteria as well as Medlar bodies overlying the nail bed with no evidence of a nevomelanocytic lesion. To our knowledge, this is the first report of Medlar bodies causing pigmented streaks in the toenails.

Scalp paraffinoma underlying squamous cell carcinoma.

We report the case of an 84-year-old man with multiple squamous cell carcinomas located on his bald scalp, arising in association with underlying paraffinoma. Histologically, poorly differentiated, acantholytic squamous cell carcinomas were located above characteristic pseudocystic spaces. Carcinomas have been reported in association with penile and breast paraffinomas, but we are unaware of any reports of squamous cell carcinoma arising over a scalp paraffinoma.

Immunohistochemical analysis of lung carcinomas with pure or partial bronchioloalveolar differentiation.

CONTEXT: In 1999, the World Health Organization redefined bronchioloalveolar carcinomas (BACs) as those neoplasms with only a pure lepidic growth pattern and no invasion. OBJECTIVES: The present study examined 45 lung cancers with a BAC component (1) to determine whether these tumors would be classified as BACs by current World Health Organization standards, (2) to quantitate the BAC component within these tumors, and (3) to see if phenotypic differences exist between the so-called invasive and noninvasive regions of these tumors. DESIGN: Retrospective review of hematoxylin-eosin-stained slides and classification of histologic grade, tumor subtype, and percentage of pure BAC pattern, with further characterization by immunohistochemical staining for thyroid transcription factor 1, cytokeratin 7, cytokeratin 20, and Ki-67 antibodies. RESULTS: Only 7 (15.6%) of the 45 tumors examined could be classified as BAC by current strict World Health Organization criteria. Those tumors, classified as nonmucinous and mixed, showed similar immunohistochemical staining for cytokeratin 7, cytokeratin 20, and thyroid transcription factor 1; mucinous tumors showed disparate staining. Significant differences in immunohistochemical staining and tumor cell proliferation were seen for the regions of tumors designated as lepidic, infiltrative, and leading edge and for the regions of tumors with different histologic grades (ie, well, moderately, and poorly differentiated). CONCLUSIONS: Nonmucinous and mixed BACs are phenotypically similar and show identical immunohistochemical staining patterns; mucinous tumors, on the other hand, show disparate immunohistochemical staining. Pulmonary neoplasms designated as adenocarcinomas with a BAC component represent a heterogenous group with a range of cell types, differentiation, growth, and immunophenotypes. Within an individual neoplasm, there are regional differences in these parameters as well.

Old world cutaneous leishmaniasis in Los Angeles: a case report, overview of the current literature, and guide for the treating dermatopathologist.

We describe a case of cutaneous leishmaniasis in a Spanish patient visiting Los Angeles. Leishmania species cause both cutaneous and visceral disease; the majority of infections with Leishmania are of the cutaneous form. Although leishmaniasis is a relatively rare occurrence in the United States, travel by United States' citizens to endemic regions and increased United States military operations in the Middle East raise the chances of encountering cutaneous leishmaniasis. The following case report and overview of the current literature outlines the major morphologic findings and current diagnostic modalities available to diagnose cutaneous leishmaniasis.