A low incidence of histiocytic sarcomatosis associated with infection of chickens with the HPRS-103 strain of subgroup J avian leukosis virus.

Ten cases of histiocytic proliferative lesions in meat-type chickens associated in low incidence with infection by subgroup J avian leukosis virus (ALV) are described. Six were field cases in adult chickens from naturally infected flocks and four were from younger birds from transmission experiments with HPRS-103 ALV or the related acutely transforming ALV strains 17 and 879. The lesions were observed mostly in the spleen and in some cases in other organs. Microscopically, the lesions were comprised mainly of pleomorphic histiocyte-like cells admixed with variable numbers of lymphoid cells. More detailed studies were carried out on two birds at 4 and 7 wk of age following infection with HPRS-103 at 1 day of age. These birds had multiple small nodular lesions in the spleen, liver, and kidney that appeared similar cytologically to the more extensive lesions in older birds. Monoclonal antibodies specific for various lymphoid and nonlymphoid accessory cells were used in immunohistochemical studies to identify a predominance of cells of monocyte/macrophage lineage, and CD4- and CD8-positive lymphocytes, in the splenic nodules. Ultrastructural studies also revealed a similar mixed population of cells. Expression of ALV group-specific antigen, and gag and ALV-J env RNA, was not a marked feature of the histiocytic lesions. The proliferative histiocytic lesion is designated a histiocytic sarcomatosis.

Porphyria cutanea tarda in a patient with hairy cell leukemia.

The case of porphyria cutanea tarda occurring in a patient treated for hairy cell leukemia is presented. Porphyria cutanea tarda has recently been associated with a variety of hematologic disorders and the acquired immunodeficiency syndrome. Potential mechanisms explaining this association are discussed.

Temporary ectropion due to topical fluorouracil.

A patient with multiple actinic keratoses was treated with the standard regimen of 5 percent fluorouracil cream. The patient noted bilateral ectropion within two weeks of receiving therapy. The ectropion completely resolved with discontinuation of therapy. This is the first reported case of transient ectropion associated with 5-fluorouracil therapy.

Common infections of the skin. Characteristics, causes, and cures.

If the skin's protective mechanisms are disrupted, cutaneous infection may result. Diagnosis is based on recognition of clinical signs. Accurate assessment of these signs and prompt initiation of appropriate treatment can help patients avoid serious complications, such as glomerulonephritis occurring with impetigo contagiosa or gangrene and sepsis occurring with cellulitis. Recurrence of skin infections is difficult to prevent, but patients should be encouraged to practice good hygiene and to avoid irritants and predisposing factors nonetheless.

Common disorders of pigmentation: when are more than cosmetic cover-ups required?

The many types of pigmentation disorders may present in diverse forms and distributions and have various causes. They can be inherited (eg, vitiligo, familial periorbital hyperpigmentation), acquired (eg, postinflammatory pityriasis alba, idiopathic guttate hypomelanosis, Becker's nevus, melasma), infectious (eg, tinea versicolor), benign and self-limiting (eg, isolated café au lait spots, photocontact dermatitis), or a sign of more serious underlying disease (eg, multiple café au lait spots, malignant acanthosis nigricans). Primary care physicians see many patients with skin complaints and can often accomplish the early recognition and appropriate treatment that is paramount to cost-effective medicine. In many cases, an important aspect of patient care is education toward realistic expectations, because even with referral and use of extensive treatment, cosmetic results may be disappointing. Assuring patients that the disorder is not dangerous and providing tips on sunscreen and cosmetic use may be the best approach in some cases.

Squamous cell carcinoma of the skin. Will heightened awareness of risk factors slow its increase?

Although squamous cell carcinoma of the skin is still less common than basal cell carcinoma, its incidence is increasing at an alarming rate. Cumulative sun exposure is a major risk factor, and deterioration of the ozone layer combined with life-style choices that promote time in the sun may account for part of the increased incidence. Other risk factors for squamous cell carcinoma include exposure to ionizing radiation, arsenic, or industrial chemicals; viral infection; preexisting burns and scars; and immunosuppression. Actinic keratosis is considered a precancerous lesion that should be watched closely. Treatment methods for squamous cell carcinoma vary depending on the size and location of the lesion. Knowledge of high-risk locations and appropriate treatment choices ensures proper care and decreases the likelihood of metastasis.

Basal cell carcinoma. Choosing the best method of treatment for a particular lesion.

Basal cell carcinoma is the most common type of malignant tumor in the United States. The five types of basal cell carcinoma (noduloulcerative, pigmented, morpheaform, and superficial basal cell carcinoma, and premalignant fibroepithelioma) vary in clinical presentation and behavior. Diagnosis is made by skin biopsy. The size, type, and site of a lesion and the age and sex of the patient affect the choice of treatment. Electrodesiccation and curettage, cryosurgery, surgical excision, Mohs' surgery, and radiation therapy are available. Knowledge of these therapies and of when they should and should not be used is important in proper management of basal cell carcinoma.

Axillary string phlebitis in pregnancy: a variant of Mondor's disease.

A 28-year-old pregnant woman had acute superficial thrombophlebitis in the right axilla. Aside from pregnancy, there were no risk factors for hypercoagulability. This case is presented as a variant of Mondor's disease. The pendulous breasts associated with her pregnancy and strenuous lifting may have predisposed the patient to the disease.

Juvenile pseudoxanthoma elasticum: recognition and management.

An 8-year-old girl had pseudoxanthoma elasticum (PXE) with the characteristic skin and ocular findings. She had no associated systemic symptoms and no family history of PXE. The disease was most likely inherited in an autosomal recessive fashion. It is reviewed with regard to etiology, inheritance, diagnosis, and, particularly, management.