Paul Chu

Histologic features of cutaneous sinus histiocytosis (Rosai-Dorfman disease): study of cases both with and without systemic involvement

Sinus histiocytosis with massive lymphadenopathy (Rosai‐Dorfnian disease) is a systemic proliferation of cells that resemble‐ the sinus histiocytes of lymph nodes. Whereas initial reports high‐lighted the often striking cervical adenopathy, more than 40% of patients have extranodal involvement. Cutaneous lesions are (Inmost common form of extranodal disease, but cases that present as cutaneous disease without lymph node involvement are rare. We examined biopsies from three patients with cutaneous lesions of sinus histocytosis, none of whom had detectable systemic involvement, and compared them to those of two patients whose lymph nodes were involved by the disease. The histology of skin lesions in all live cases showed dense nodular or diffuse infiltrates of “hisliocytes,” emperipolesis of lymphocytes, neutro‐phils, and plasma cells. “Histiocytes” were present in lumens of dilated lymphatics. At the peripheries of the lesions were lymphoid aggregates and thick‐walled vessels surrounded by plasma cells. Staining with anti‐S‐100 protein antibody showed marked cytoplasmic positively in the “hisliocytes” in each case. The only features that differed among the two groups were the presence ol pseudoepitheliomalous hyperplasia and infiltrates of eosinophils in one case in which the disease was limited to the skin. We believe that cutaneous sinus histiocytosis can be specifically diagnosed by skin biopsy. Because cutaneous sinus histiocytosis may be unfamiliar to general palhologists, dermatopathologists, and dermatologists, cases limited to the skin may be under‐recognized.

An eruptive vascular proliferation resembling acquired tufted angioma in the recipient of a liver transplant

A 59-year-old man developed grouped erythematous papules on the skin of the right axilla and arm shortly after orthotopic liver transplantation. Histologic changes closely resembled those of acquired tufted angioma, with capillary lobules studding the dermis. The lesions spontaneously involuted over several months. Histopathologic and immunohistochemical findings excluded Kaposis sarcoma and bacillary angiomatosis, the two vascular proliferations most frequently seen in the immunocompromised host. We believe that our case is one of acquired tufted angioma appearing as an eruptive condition similar to eruptive pyogenic granuloma, to which it seems closely related. The involution of lesions in this case is unexplained.

Solitary plexiform neurofibroma is not pathognomonic of von Recklinghausen's neurofibromatosis: a report of a case

A 42‐year‐old Caucasian man presented with a 1.8‐cm nodule in the proximal thigh (Fig. 1) that had been slowly enlarging for approximately 5 years. The patient had no family history of neurofibromatosis. Physical examination revealed none of the other stigmata of this neurocutaneous disorder. D.A.F. performed an elliptical excision as an out‐patient procedure. Grossly, the lesion was homogeneously opalescent and gelatinous. The tissue was fixed in 10% formalin and embedded in paraffin. Routine hematoxylin and eosin stained sections were prepared. The most notable feature on low power magnification was a large, circumscribed, lobular proliferation of spindle cells in a loose fibrillar background that distorted much of the dermis and subcutaneous fat (Fig. 2). On high power magnification, a population of cells with ovoid and S‐shaped nuclei admixed within densely packed eosinophilic collagenous material was seen at the center of the lobule (Fig. 3A). A small amount of mucin was also present. Within this cellular area, a dense population of S‐shaped spindle cells with eosinophilic cytoplasm was arranged in a parallel array forming microfascicles. At the periphery of this cellular component, a similar population of cells was arranged against a loose fibrillar background of abundant mucin (confirmed by colloidal iron stain) and scattered mast cells (Fig. 4). Lining the lobule was a compressed rim of thin, delicate collagen bundles and perineurial cells. Pleomorphic nuclei and mitotic figures were not observed. The surrounding dermis and subcutaneous tissue were unremarkable. Thickened collagen bundles at the center of the lobule could be seen with a frichrome stain. An S‐100 protein immunoperoxidase stain highlighted scattered Schwann cells within the lobule (Fig. 3B), and nerve bundles adjacent to the neurofibroma served as infernal positive controls.

Idiopathic eruptive macular pigmentation: a case of 21 years' duration

Idiopathic eruptive macular pigmentation is a rare condition characterized by asymptomatic pigmented macules involving the neck, trunk, and proximal portions of the extremities. Age at onset usually varies from 1 to 20 years. The lesions usually appear abruptly and remit spontaneously over months to years. An unusual case of a 24-year-old woman with idiopathic eruptive macular pigmentation lasting 21 years was characterized by several periods of spontaneous resolution followed by recurrences.

Multiple infundibulocystic basal cell carcinomas in association with human immunodeficiency virus

Infundibulocystic basal cell carcinoma (IBCC) is a relatively recently described variant of basal cell carcinoma that is controversial and not universally accepted. Excluding cases of nevoid basal cell carcinoma syndrome, IBCC usually presents as a small, solitary, superficial lesion on the face of older persons. There have been previous reports of diffusely distributed, multiple similar lesions, but there is disagreement about the diagnosis in these cases. We present a case of a 43‐year‐old man with multiple papular lesions which we believe represent IBCC in the setting of infection with the human immunodeficiency virus (HIV).

Four Views of Areolar Melanosis: Clinical Appearance, Dermoscopy, Confocal Microscopy, and Histopathology

Melanosis of the areola is a benign process characterized by hyperpigmentation of basal keratinocytes in the presence of normal to slightly increased numbers of melanocytes. It can simulate malignant melanoma clinically and it therefore, can present a diagnostic dilemma. We recently reported a case in which a pregnant patient presented with a growing, changing pigmented lesion on her right breast. Examination of the skin revealed a large, poorly demarcated and asymmetric hyperand hypopigmented patch spanning the left lower quadrant of the right areola and nipple without any associated induration or ulceration (Figure 1). Further evaluation of the lesion with dermoscopy, confocal microscopy, and histopathology ruled out malignancy and led to a diagnosis of areolar melanosis. In this report, we provide the first description of this entity under confocal microscopy and correlate its features across the various imaging modalities utilized.

A comparison of the pulmonary toxicity produced by metal-free and copper-complexed analogs of bleomycin and phleomycin

Abstract Previous studies from this laboratory indicated that the terminal amine groups adjacent to the thiazole rings of bleomycins are important determinants of pulmonary toxicity. The present study examines the relation between pulmonary toxicity and molecular sites other than the terminal amine. Phleomycins differ from bleomycins in having a thiazoline instead of a thiazole ring. The contribution of the thiazole rings and also the metal binding sites were assessed by studying the pulmonary toxicity produced by metal-free and copper-complexed bleomycins and phleomycins bearing identical terminal amines. Bleomycin and phleomycin CHP; bleomycin B6, bleomycin B6 Cu, phleomycin G, phleomycin G Cu, bleomycin PEPP, bleomycin PEPP Cu, and phleomycin PEPP Cu (1 and 10 nmol) were administered to DBA 2J mice by the endotracheal route. The abilities of these analogs to produce pulmonary fibrosis and metaplasia were evaluated by histopathologic criteria and compared to the activity of a mixture of bleomycins (Blenoxane). Bleomycin B6 and phleomycin G tended to be more toxic than the other analogs, while the toxicities of bleomycin and phleomycin CHP and PEPP were comparable to Blenoxane. Analogous bleomycins and phleomycins with identical terminal amine groups were equally toxic. Copper-complexed analogs retained the toxicity of the respective metal-free bleomycin or phleomycin. These studies indicated that neither administration as a copperchelate nor substitution of a 4,5-dihydrothiazole ring for a thiazole ring affected pulmonary toxicity. These results are consistent with the importance of the variable bleomycin terminal amine groups in the production of lung injury.

Pedunculated malignant melanoma

Background. The pedunculated melanoma is an unusual variant of nodular melanoma that presents a challenge in staging and management. Objective. We discuss the clinical and histopathologic characteristics of a case of pedunculated melanoma and present a brief review of the literature. Methods. Routine stain with hematoxylin and eosin was performed on tissue specimens. Results. The pedunculated melanoma was excised. Sentinel lymph node dissection was performed and was negative for the presence of melanoma. Conclusions. Pedunculated melanoma is a rare type of melanoma. Conventional staging methods for melanoma may not be reliable in this type of tumor. Complete workup, possibly including sentinel lymph node dissection, should be performed in all patients with pedunculated melanomas.