Strongyloidiasis, an infection by the small intestinal nematode Strongyloides stercoralis, is encountered worldwide but is most common in tropical climates.
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Paragonimiasis is infection by the oriental lung fluke Paragonimus westermani or by one of several other species of Paragonimus.
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REAH is an expansile mass that causes upper respiratory symptoms and discomfort mainly in adults .
Symptoms at presentation vary and are similar to those that accompany chronic sinusitis, eg, nasal congestion, nasal obstruction, headaches, facial pain, epistaxis, and hyposmia.
Endoscopy does not reveal any distinguishing features to suggest a diagnosis of REAH, and neither CT nor magnetic resonance imaging produces a specific signal intensity that can help the clinician distinguish REAH from other sinus lesions.
Distinctive histologic features of REAH include a glandular component that originates in the overlying surface respiratory epithelium and polypoid growths that represent a proliferation of respiratory epithelial adenomatoid tissue.
It is important to recognize this lesion, however, because it can be confused histopathologically with other disease processes that require a significantly different treatment approach.
Included in the microscopic differential diagnosis of REAH are inflammatory polyps , inverted Schneiderian papillomas , and well-differentiated adenocarcinoma .
Pathologists must be aware of this entity to avoid overdiagnosis and overly aggressive surgical procedures.
Goblet cell carcinoid tumors accounts for 6% of appendiceal carcinoid tumors.
Histologically, GCC has features of both epithelial and carcinoid tumors and is considered intermediate between classic appendiceal carcinoid tumors and adenocarcinomas.
Although some authors believe that this tumor is of low-grade malignancy , it has a more aggressive natural history than the classic carcinoid tumors with variable malignant potential .
At diagnosis the tumor most commonly has transmural extension with diffuse infiltration into the periappendiceal fat and perineural invasion.
Although simple appendectomy may be adequate for most patients, some patients may require a more radical procedure including right hemicolectomy, particularly if there is involvement at the base of the appendix with cecal wall inflammation, lymph node metastasis, tumor size greater than 2 cm, or high-grade tumor histology.
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PASH is a benign proliferation of the mammary stromal tissue. On histologic analysis, it shows complex interanastomosing slit-like spaces which appear to be lined by spindle cells in the breast parenchyma.
It is important to differentiate the lesion from angiosarcoma. It can be confused histologically with PASH. Angiosarcoma often shows a more aggressive infiltrative pattern into surrounding fibroadipose breast tissue and is highly vascular, lined by endothelial cells. It does not show a collagenous stroma. Angiosarcoma displays positive immunoreactivity for CD31 and, although less frequently and with less sensitivity, for the factor VIII–related or von Willebrand factor antigens.
PASH is associated with several benign entities including proliferative and nonproliferative fibrocystic changes, such as fibroadenomas, gynecomastia, normal breast tissue, and sclerosing lobular hyperplasias. The etiology and pathogenesis remain unknown.
Local excision is curative in most cases. Although recurrence may occur, the overall rate is low. Follow-up after excision is recommended as local recurrence has been reported.
Hyalinizing trabecular tumor (HTT) of the thyroid gland is a rare neoplasm of follicular cell origin that was initially described by Carney et al. This rare form of tumor is commonly circumscribed or encapsulated, consisting of polygonal and spindle cells arranged in a trabecular pattern and separated by hyalinized stroma .Microscopically, this neoplasm shows hyaline contents and nuclei with frequent grooves and intranuclear inclusions, mimicking the presence of amyloid in medullary thyroid carcinoma or the nuclear features of papillary thyroid carcinoma , potentially leading to misdiagnosis of this benign tumor as malignant based on preoperative fine needle aspiration (FNA) cytology. HTT is generally accepted to be a benign tumor , in which the majority of tumors do not present with aggressive behavior such as capsular/vascular invasion, local recurrences, or distant metastases.
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LAZY-LEUCOCYTE SYNDROME
A New Disorder of Neutrophil FunctionA primary abnormality of leucocyte function—a deficiency of chemotaxis— has been found in two unrelated children with recurrent infection. The syndrome is characterised by recurrent stomatitis, otitis, gingivitis, and low-grade fevers, normal humoral and cellular immunity, severe peripheral neutropenia, normal numbers of mature, morphologically normal neutrophils in the bone-marrow, poor peripheral blood leucocyte response to chemical or inflammatory stimulation, poor neutrophil chemotaxis, and severely impaired random mobility of neutrophils. Neutrophils from peripheral blood or from bone-marrow suspensions had normal phagocytic and bactericidal activities, but almost no chemotactic activity. Infection and fever in these patients seems to result from an inability to release and mobilise otherwise functionally normal neutrophils in the presence of bacterial stimuli. The precise receptor defect in these ” lazy leucocytes ” remains to be defined.
