Reactive histiocytic hyperplasia with hemophagocytosis in hematopoietic organs: a reevaluation of the benign hemophagocytic proliferations.

Histiocytic hyperplasia with hemophagocytosis (HHH) is a relatively rare condition that has often been mistaken for a neoplastic disorder, but which most frequently represents a secondary reactive phenomenon whose associated risk factors have not yet been clearly defined. Histologic sections of hematopoietic organs (bone marrow, lymph nodes, and spleen) from 230 consecutive adults autopsies were reviewed to identify cases of HHH and to correlate them with clinical and autopsy findings. Moderate to severe HHH was present in the bone marrow in 102 and 230 cases, in the lymph nodes in 79 of 191 cases, and in the spleens of 16 of 209 cases.

A reappraisal of Richter's syndrome. Development of two phenotypically distinctive cell lines in a case of chronic lymphocytic leukemia.

Richter's syndrome, the development of a malignant lymphoma in a patient with preexisting chronic lymphocytic leukemia (CLL) is an infrequent but well-documented phenomenon generally thought to represent a monoclonal proliferation of B-lymphocytes arising from the CLL. A heterogeneous population of cells consisting of sheets of transformed lymphocytes in combination with clusters of bizarre, atypical histiocytes developed in a patient with a history of longstanding CLL. Immunocytochemistry using a panel of monoclonal and polyclonal antibodies by immunoperoxidase techniques identified the presence of both B-lymphocytic and monocytic-histiocytic cell lines of differentiation.

A characteristic vesiculobullous eruption in patients with chronic lymphocytic leukemia.

We report ten cases of a characteristic vesiculobullous eruption in patients with chronic lymphocytic leukemia. Clinically, six lesions were thought to represent insect bites. All ten patients had bone marrow examinations that confirmed the diagnosis of chronic lymphocytic leukemia.

Membranous fat necrosis.

We report the case of a 66-year-old man with nodular lesions on the chest that were clinically diagnosed as epidermal cysts. Histologically the lesions consisted of fat necrosis with cystic spaces lined by striking membranous structures, mimicking a parasitic cuticle and exhibiting all the staining reactions of ceroid. Retrospective review of 33 consecutive cases of fat necrosis revealed similar membranous changes in 21% of the cases.

Hepatitis B surface antigen positive skin lesions. Two case reports with an immunoperoxidase study.

This study represents the first two case reports of skin lesions positive for hepatitis B surface antigen (HBsAg) with the immunoperoxidase technique. A 25-year-old man and a 64-year-old woman with serologic evidence of acute B viral hepatitis and concurrent skin lesions are presented. Immunoperoxidase study of the skin lesions for HBsAg revealed strong positive staining of squamous epidermal cells, eccrine sweat glands, and endothelial cells in the superficial papillary dermis.

Peritoneal keratin globules in uterine adenosquamous carcinoma.

We have described a previously unreported lesion--peritoneal keratin globules in uterine adenosquamous carcinoma. We postulate that the keratin globules are derived from sloughed uterine adenosquamous carcinoma which gains access to the peritoneum through retrograde dissemination via the fallopian tubes, and we suggest that the finding of these globules does not alter the prognosis and staging of the primary carcinoma.

A malignant neoplasm with features of both squamous cell carcinoma and malignant melanoma.

A case of a malignant neoplasm with features suggestive of both malignant melanoma and squamous cell carcinoma is reported. The neoplastic cells were positive for both S-100 protein and keratin when stained by the indirect peroxidase-antiperoxidase method. The literature on other instances of bi- or multidirectional differentiation of neoplastic cells is reviewed.

Tunga penetrans in south Florida.

We have described a 25-year-old man with infestation of the feet by the burrowing flea Tunga penetrans, acquired in Brazil. We have also presented the microscopic characteristics of the flea and the histologic differential diagnosis.

Familial multicentric angiofollicular lymphoid hyperplasia.

Multicentric angiofollicular lymphoid hyperplasia occurred in a brother and a sister. This is the first report of familial incidence of this disease, which raises the possibility of a hereditary or environmental factor in its pathogenesis.

Coexistence of Castleman's disease and Kaposi's sarcoma. Report of a case and a speculation.

A case report of multicentric Castleman's disease associated with Kaposi's sarcoma is presented. Histologic examinations of cutaneous lesions and of an axillary lymph node were made. The cutaneous lesions showed Kaposi's sarcoma and a lymph node revealed Castleman's disease and foci of spindle cells characteristic of Kaposi's sarcoma.

Woringer-Kolopp disease (pagetoid reticulosis).

We report the clinical, histopathological, and ultrastructural features of a case of Woringer-Kolopp disease, review the literature, and discuss the relationship of the condition to mycosis fungoides. At the present time it is best to regard Woringer-Kolopp disease as a form of cutaneous T-cell lymphoma that may remain localized for many years or may eventually be associated with widespread mycosis fungoides.