Extramedullary hematopoiesis in a pyogenic granuloma.

Extramedullary hematopoiesis is rare outside the setting of significant primary hematologic disease. We describe this phenomenon in an exuberant pyogenic granuloma in an otherwise healthy man. We postulate that this vascular lesion provided a suitable milieu for homing and proliferation of stem cells.

Histopathology of psoriasis treated with zinc pyrithione.

Psoriasis is still a relatively poorly understood inflammatory dermatosis that is resistant to many therapies. Because the pathogenesis is poorly understood, rational treatment is elusive. Until recently, the North American public was able to achieve successful resolution with an over-the-counter topical preparation marketed for dandruff and seborrheic dermatitis called SkinCap, which has now been withdrawn from the market. The purpose of this study was to examine the histologic changes induced by this preparation in a well-developed psoriatic plaque. Serial punch biopsies were taken over a 2-week period during which time SkinCap was applied topically twice daily. The biopsies were examined histologically, and features were evaluated semiquantitatively. The classic histologic features of psoriasis resolved completely over 2 weeks, with the reversal beginning with disappearance of neutrophils and the most striking finding being prominent apoptosis at 48 hours. The mechanism of this normalization is unknown. Hypotheses include blockage of cytokine and growth factor effect at some level and induction of apoptosis.

Cytology of ascitic fluid in a patient with granulocytic sarcoma (extramedullary myeloid tumor). A case report.

BACKGROUND: Granulocytic sarcoma (GS) is the rare extramedullary manifestation of acute myeloid leukemia that may precede or be concurrent with leukemic infiltration of bone marrow or herald blastic transformation of a chronic myeloproliferative disorder. It has been found in most body sites and shows no age or sex predilection, necessitating its inclusion in the differential diagnosis of undifferentiated neoplasms. CASE: A 36-year-old female presented with a three-year history of abdominal pain, jaundice and fluctuating abdominal girth. Cytology of the ascitic fluid revealed myeloid cells of eosinophilic lineage at all stages of differentiation, with many undifferentiated cells. Immunohistochemical studies on a cell block confirmed the diagnosis of granulocytic sarcoma, which excluded the differential diagnoses of Hodgkin's disease, non-Hodgkin's lymphoma and Langerhans histiocytosis. CONCLUSION: Granulocytic sarcoma may present as a serous effusion and can be diagnosed on a cytologic specimen.

Cytomegaly of pancreatic D cells in triploidy.

Triploidy is a common chromosomal aberration seen in 1% of clinically recognized human pregnancies. Development beyond 10 weeks is unusual. Occasionally fetuses survive past 20 weeks; however, they usually present as a stillbirth with only a few managing some hours of independent life. The clinical features of these infants cover a wide spectrum, but a consistent feature is organ hypoplasia and hypotonia. We observed marked enlargement of somatostatin-producing cells (D cells) in the pancreata of triploid fetuses. Somatostatin-producing cells are widely distributed in normal mammals although concentrated in the pancreas and gastrointestinal tract, generally being antiproliferative and having an inhibitory effect on various functions. The control of fetal growth is not well understood. There is, however, some evidence that somatostatin does play a significant part and our consistent observation of cytomegaly of the pancreatic D cells in growth-retarded triploid fetuses provides more support for this contention.

Multiple sclerosis with medullary plaques and fatal sleep apnea (Ondine's curse).

We report 2 patients with multiple sclerosis (MS) who were symptomatic but ambulatory, and died in their sleep. Sleep studies in 1 patient showed hypercarbia and hypoxia accompanying sleep. In both cases autopsy showed plaques of multiple sclerosis in the medulla oblongata, incompletely involving the neuroanatomic areas of the medullary reticular formation controlling automatic breathing. A systematic analysis of the location of the plaques in relation to areas known to be important in breathing control revealed that the regions corresponding to the ventral nuclear complex of respiratory control in animals were incompletely and unilaterally involved in both cases. Close correlation with nuclei that have been demonstrated in animal experiments to be important in descending respiratory control of phrenic and intercostal musculature was not possible due to possible differences in anatomy between animals and humans, and the fact that plaques of MS affect axons of passage and spare neuronal cell bodies. Nevertheless, the cases clearly illustrate that patchy, unilateral lesions of the medullary reticular formation in humans can give rise to sleep disordered breathing. The cases also illustrate the risk of death during sleep in MS patients with demyelination in the medulla oblongata, and demonstrate the need to carefully examine the medulla in MS patients if they die unexpectedly during sleep.

Diffuse-variant tenosynovial giant cell tumor: a rare and aggressive lesion.

The diffuse-variant tenosynovial giant cell tumor is rare. Although it shares histologic features with the exclusively intra-articular pigmented villonodular synovitis and local tenosynovial giant cell tumor, its behavior differs dramatically, being locally very aggressive. We report a case of a diffuse-variant aggressive tenosynovial giant cell tumor that, although diploid by flow cytometry, demonstrated trisomy 7 and 5 as well as clonal rearrangements involving chromosomes 1, 3, and 15. These cytogenetic abnormalities may be markers for aggressive behavior and useful for directing treatment.