Stains and Marker122.docx

Stains and Markers Stains Perls' Prussian blue stain; iron in hemosiderin turns blue to black when exposed to potassium ferrocyanide. Toulidine blue: mastocytosis Thioflavin T: amyloidosis Cytokeratin 7: extramammary Paget's disease: Myeloperoxidase stains cells with myeloid differentiation such as...

Stains and Markers Stains Perls' Prussian blue stain; iron in hemosiderin turns blue to black when exposed to potassium ferrocyanide. Toulidine blue: mastocytosis Thioflavin T: amyloidosis Cytokeratin 7: extramammary Paget's disease: Myeloperoxidase stains cells with myeloid differentiation such as leukemia cells DFSP is CD34 positive and factor XIIIa negative S100 protein is a non-specific stain that is commonly used as an adjunctive marker in the diagnosis of melanoma. Mucicarmine stain: adenocarcinoma- Cryptococcus capsule stain red and Rhinosporidium. Periodic Acid Schiff (PAS) is useful in identifying fungi, parasites, glycogen and the basement membrane. The wall of the organism stains red. Fontana Masson stains melanin black and therefore helps identify dematiaceous (melanin producing) fungi. Gormorimethenamine silver stains fungi, parasites, Donovan bodies and Rhinoscleromablack. Von Kossa stain is used to identify calcium by staining it black. Neuron specific enolase stains merkel cells. Vimentin stains melanocytic lesions, sarcomas and lymphomas. S100 and HMB45 stains melanocytic lesions, such as melanoma. Markers CD68+ve, CD1a -ve, S100+ve in Rosai Dorfman syndrome. CD+ve, vimentin +ve [DFSP] S100+ve, CD68+ve [atypical fibroxanthoma] S100+ve, MBP +ve, vimentin +ve [shwanomma or Neurolemmoma] S100 +ve, HMB45+ve, vimentin +ve [melanoma] Vimentin +ve, Smooth muscle actin +ve [glomus tumer] Vimentin +ve, Smooth muscle actin +ve, Desmin +ve [leimyosarcoma] Merkel cell carcinoma CK20 Paget disease CK7, CEA, EMA Involuting Hemangioma…… Revolutingprliferative Hemangioma… Notes: FMF: pyrin / MEFV gene Spastic paraplegia: SPG31 Mastocytosis: CKIT Early onset sarcoid: CARD15 (NOD2) gene Henoch Schoenlein purpura: MEFV gene 143 Board Vital Board Vital A 63-year-old female presents with a life-long history of a papillomatous yellow-orange plaque on the scalp. Her daughter recently noticed a smooth, pink nodule paracentrally within the plaque and advised her mom to see a dermatologist. A biopsy of the nodule and part of the surrounding plaque was performed. Based on the clinical and histologic findings, what is the most likely diagnosis? Basal cell carcinoma arising in association with nevus sebaceus Trichoblastoma arising in association with nevus sebaceus Syringocystadenoma papilliferum arising in association with nevus sebaceus Well-differentiated squamous cell carcinoma arising in association with nevus sebaceus Desmoplastic melanoma arising in association with nevus sebaceous. Explanation: The image shows the histology of trichoblastoma. The clinical scenario depicts a tumor that developed within a nevus sebaceus. Nevus sebaceus typically presents at birth as a solitary, yelloworange plaque on the scalp or face, that become mamillated or papillomatous during puberty due to androgenic effects to its sebaceous glands. The most common neoplasm to arise from nevus sebaceus is trichoblastoma, although syringocystadenoma papilliferum used to represent this role. Basal cell carcinoma only accounts for less than 1% of secondary neoplasms arising from nevus sebaceus. The picture depicts a trichoblastoma, not basal cell carcinoma. The lack of mucinous stroma and peritumoral clefting makes the diagnosis of basal cell carcinoma unlikely. Furthermore, the most common neoplasm to arise from nevus sebaceus is trichoblastoma. Syringocystadenoma papilliferum is characterized by papillae and ducts lined by cuboidal or columnar cells with abundant basophilic cytoplasm that project into a cystic lumen. Plasma cells are often seen in the stroma. Syringocystadenoma papilliferum can arise from a nevus sebaceus, although trichoblastomas are the most common neoplasms that do so. The picture depicts a trichoblastoma, not that of a squamous cell proliferation, which typically appear as eosinophilic proliferations of keratinocytes, especially when well- differentiated. Desmoplastic melanoma is in the differential diagnosis of desmoplastic trichoepithelioma / trichoblastoma. The image depicts a trichoblastoma consisting of nodular collections of cytologically bland basaloid cells within a fibrous stroma. This is in stark contrast with the cytologically atypical strands and cords of amelanotic fusiform melanocytes within a prominently fibrous stroma seen in desmoplastic melanoma. In suspected carcinoid syndrome, which urine test should be ordered? 5-HIAA Metanephrines RBCs Protein Explanation: Carcinoid syndrome occurs in approximately 5% of carcinoid tumors and becomes clinically evident when vasoactive substances from the tumors enter the systemic circulation escaping hepatic degradation. Interestingly, if the primary tumor is from the GI tract (hence releasing serotonin into the hepatic portal circulation), carcinoid syndrome generally does not occur until the tumor has metastasised to the liver, because prior to metastasis, the released serotonin would be metabolised in the liver. If the primary is in the lung, no metastasis needs to occur for carcinoid syndrome to become clinically evident, as the secretion occurs directly in the systemic circulation. Common symptoms include flushing, pellagra-like dermatitis, and scleroderma-like skin changes. The best test is urinary 5-HIAA (the degradation product of serotonin) which is 100% sensitive. What is the most common cancer in POEMS syndrome? a. Osteosclerotic myeloma Castleman’s disease Polycythemia Plasmacytoma Waldenstrom macroglobulinemia Explanation: POEMS is a rare paraneoplastic syndrome characterized by polyneuropathy, organomegaly,endocrinopathy/edema, monoclonal plasma cell proliferative disorder and skin abnormalities (includinghyperpigmentation and hypertrichosis). Although various monoclonal plasma cell proliferative disorders have been associated with POEMS, the most common are osteosclerotic myeloma or monoclonal gammopathy of unknownsignificance.The type of light chain seen in POEMS syndrome is almost always lambda. The associated heavy chain is most commonly IgA or IgG. .Castleman’s disease, plasmacytoma and Waldenstrom macroglobulinemia occur in only a minority of cases Where on the body would this lesion most likely present? Scrotum Trunk Lip Scalp Explanation: This is a slide of a venous lake, as evidenced by the single large dilated venule located in the dermis. Clinically a venous lake is a blue-black macule that appears on sun-damaged skin, most often present on the lower lip or the ear.