Kaposi sarcoma (KS) is a low-grade vascular neoplasm associated with human herpesvirus-8 (HHV-8) infection. Clinically, lesions commence as blue-red macules that may develop into plaques and eventually into nodules. T...Kaposi sarcoma (KS) is a low-grade vascular neoplasm associated with human herpesvirus-8 (HHV-8) infection. Clinically, lesions commence as blue-red macules that may develop into plaques and eventually into nodules. The histologic appearance spans a broad spectrum and varies with the stage of the lesion. At each stage, KS has significant morphologic overlap with other vasoproliferative lesions. Recently, we encountered 6 KS tumors that histologically mimicked pyogenic granuloma (PG), a common benign vascular tumor of the skin that usually does not figure in the histologic differential diagnosis of KS. We stained 6 PG-like KS and 28 PGs with a mouse monoclonal antibody (13B10) against HHV-8 latent nuclear antigen-1 (LNA-1) to determine the utility of immunoperoxidase staining in distinguishing KS from PG. All 6 PG-like KS demonstrated nuclear staining for HHV-8 LNA-1. No staining was identified in any of the 28 PGs. Histologic criteria often used to differentiate between these two entities were not helpful in our cases. The only distinguishing feature was the presence or absence of HHV-8 LNA-1 staining. The presence of HHV-8 LNA-1 nuclear staining seems to be a specific marker for KS when comparing PGs and PG-like KS. Immunoperoxidase staining for HHV-8 LNA-1 is a useful diagnostic tool in this setting.展开更多
The unusual combination of Hirschsprung’s disease and Achalasia in one case treated by standard procedures led to the discussion about RET germ-line mutations and consequently to the speculation about higher risk for...The unusual combination of Hirschsprung’s disease and Achalasia in one case treated by standard procedures led to the discussion about RET germ-line mutations and consequently to the speculation about higher risk for multiple endocrine neoplasia syndrome type 2-related tumors.Although amutation could be excluded by sequence analysis in this case, the correlation of these specific diseases affords additive investigations to make sure that no further prophylactic procedures were necessary.展开更多
Erythema nodosum (EN) is the most common panniculitis and histologically represents the prototype of a septal panniculitis. However, the histologic findings can be quite variable. We describe four patients with EN who...Erythema nodosum (EN) is the most common panniculitis and histologically represents the prototype of a septal panniculitis. However, the histologic findings can be quite variable. We describe four patients with EN who each underwent two consecutive biopsies. In each case, the first biopsy showed histopathologic features that fall outside the usual spectrum of disease. Two cases showed predominantly neutrophilic infiltrates with focal suppuration as well as vasculitis of medium-sized arteries. The areas of suppuration were more extensive in the first case prompting special stains for microorganisms that were all negative. The third case demonstrated a lobular panniculitis with a predominantly lymphohistiocytic infiltrate. Special stains were negative in this case as well. The fourth case revealed vasculitis of a medium sized artery, small vessel vasculitis, and a mixed septal and lobular panniculitis with a polyclonal population of atypical lymphocytes. In all patients, the clinical course and the subsequent biopsy were classic for EN. We conclude that lobular neutrophilic panniculitis with suppuration, small vessel vasculitis, and even medium vessel arteritis may rarely occur in EN. There are few clues in these unusual cases that allow for a specific diagnosis from the start, and often, a second biopsy is required.展开更多
文摘Kaposi sarcoma (KS) is a low-grade vascular neoplasm associated with human herpesvirus-8 (HHV-8) infection. Clinically, lesions commence as blue-red macules that may develop into plaques and eventually into nodules. The histologic appearance spans a broad spectrum and varies with the stage of the lesion. At each stage, KS has significant morphologic overlap with other vasoproliferative lesions. Recently, we encountered 6 KS tumors that histologically mimicked pyogenic granuloma (PG), a common benign vascular tumor of the skin that usually does not figure in the histologic differential diagnosis of KS. We stained 6 PG-like KS and 28 PGs with a mouse monoclonal antibody (13B10) against HHV-8 latent nuclear antigen-1 (LNA-1) to determine the utility of immunoperoxidase staining in distinguishing KS from PG. All 6 PG-like KS demonstrated nuclear staining for HHV-8 LNA-1. No staining was identified in any of the 28 PGs. Histologic criteria often used to differentiate between these two entities were not helpful in our cases. The only distinguishing feature was the presence or absence of HHV-8 LNA-1 staining. The presence of HHV-8 LNA-1 nuclear staining seems to be a specific marker for KS when comparing PGs and PG-like KS. Immunoperoxidase staining for HHV-8 LNA-1 is a useful diagnostic tool in this setting.
文摘The unusual combination of Hirschsprung’s disease and Achalasia in one case treated by standard procedures led to the discussion about RET germ-line mutations and consequently to the speculation about higher risk for multiple endocrine neoplasia syndrome type 2-related tumors.Although amutation could be excluded by sequence analysis in this case, the correlation of these specific diseases affords additive investigations to make sure that no further prophylactic procedures were necessary.
文摘Erythema nodosum (EN) is the most common panniculitis and histologically represents the prototype of a septal panniculitis. However, the histologic findings can be quite variable. We describe four patients with EN who each underwent two consecutive biopsies. In each case, the first biopsy showed histopathologic features that fall outside the usual spectrum of disease. Two cases showed predominantly neutrophilic infiltrates with focal suppuration as well as vasculitis of medium-sized arteries. The areas of suppuration were more extensive in the first case prompting special stains for microorganisms that were all negative. The third case demonstrated a lobular panniculitis with a predominantly lymphohistiocytic infiltrate. Special stains were negative in this case as well. The fourth case revealed vasculitis of a medium sized artery, small vessel vasculitis, and a mixed septal and lobular panniculitis with a polyclonal population of atypical lymphocytes. In all patients, the clinical course and the subsequent biopsy were classic for EN. We conclude that lobular neutrophilic panniculitis with suppuration, small vessel vasculitis, and even medium vessel arteritis may rarely occur in EN. There are few clues in these unusual cases that allow for a specific diagnosis from the start, and often, a second biopsy is required.
