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7 楼 发表于2006-10-11 10:26:00举报|引用
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The anatomic location of the lesion is identified as "subcutaneous", and the lesion permeates adipose tissue with "nerves traversing through the lesion". In addition to lymphoproliferative disorders, I would consider a few soft tissue malignancies in my differential diagnosis.
Lymph nodes normally exist in the medial aspect of elbow and may rarely be involved by a primary nodal lymphoma. With the large and multinodular confluent tumor at hand, it's difficult to determine whether it arose from a lymph node or not. This hypercellular malignant neoplasm involves the dermis and subcutis. Although I have not seen its relationship with dermal adnexa and epidermis, cutaneous anaplastic large cell lymphoma (ALCL, Ki-1 lymphoma) certainly deserves serious consideration. Most ALCL are of T/Null cell phenotype. Unlike the systemic (disseminated nodal form) ALCL in children and young adults (often with t(2;5)), primary cutaneous ALCL are ALK-negative, usually indolent, and not rapidly progressive unless it has evolved secondarily from peripheral T cell lymphoma, mycosis fungoides and lymphomatoid papulosis.
Because of their unique biologic behaviors, all lymphomas should be carefully classified and graded. Preferably, investigative immunohistochemistry of this case should include two T cell markers, two B cell markers, CD30, EMA and ALK-1. In my limited experience, large neoplastic cells in ALCL have horseshoe-like or multilobated nuclei, single or multiple nucleoli, and abundant pale or amphophilic cytoplasm. There usually are associated prominent apoptosis (even necrosis), and varying densities of admixed small lymphocytes and histiocytes. There appear to be scattered small lymphocytes in some of the photos. In my view, many neoplastic cells in this case are plasmacytoid. Plasmacytoid appearance is not specific for plasmacytoma, but I would add CD138, kappa and lambda light chains in my immunohistochemical workup.
A few soft tissue malignancies may show similar histopathology. They include synovial sarcoma, clear cell sarcoma of tendon and aponeurosis, and epithelioid malignant peripheral nerve sheath tumor (MPNST). Given the implications on different treatment and prognosis, I would recommend PAS stain and cytokeratin (AE1/AE3), EMA, CD99, S100, HMB45, Melan A, and MiTF in the immunistochemical workup. FISH testing for t(12;22) and t(X;18) can aid in the diagnosis of clear cell sarcoma (of tendon and aponeurosis) and synovial sarcoma, respectively.
I look forward to hearing more about this interesting case.
The anatomic location of the lesion is identified as "subcutaneous", and the lesion permeates adipose tissue with "nerves traversing through the lesion". In addition to lymphoproliferative disorders, I would consider a few soft tissue malignancies in my differential diagnosis.
Lymph nodes normally exist in the medial aspect of elbow and may rarely be involved by a primary nodal lymphoma. With the large and multinodular confluent tumor at hand, it's difficult to determine whether it arose from a lymph node or not. This hypercellular malignant neoplasm involves the dermis and subcutis. Although I have not seen its relationship with dermal adnexa and epidermis, cutaneous anaplastic large cell lymphoma (ALCL, Ki-1 lymphoma) certainly deserves serious consideration. Most ALCL are of T/Null cell phenotype. Unlike the systemic (disseminated nodal form) ALCL in children and young adults (often with t(2;5)), primary cutaneous ALCL are ALK-negative, usually indolent, and not rapidly progressive unless it has evolved secondarily from peripheral T cell lymphoma, mycosis fungoides and lymphomatoid papulosis.
Because of their unique biologic behaviors, all lymphomas should be carefully classified and graded. Preferably, investigative immunohistochemistry of this case should include two T cell markers, two B cell markers, CD30, EMA and ALK-1. In my limited experience, large neoplastic cells in ALCL have horseshoe-like or multilobated nuclei, single or multiple nucleoli, and abundant pale or amphophilic cytoplasm. There usually are associated prominent apoptosis (even necrosis), and varying densities of admixed small lymphocytes and histiocytes. There appear to be scattered small lymphocytes in some of the photos. In my view, many neoplastic cells in this case are plasmacytoid. Plasmacytoid appearance is not specific for plasmacytoma, but I would add CD138, kappa and lambda light chains in my immunohistochemical workup.
A few soft tissue malignancies may show similar histopathology. They include synovial sarcoma, clear cell sarcoma of tendon and aponeurosis, and epithelioid malignant peripheral nerve sheath tumor (MPNST). Given the implications on different treatment and prognosis, I would recommend PAS stain and cytokeratin (AE1/AE3), EMA, CD99, S100, HMB45, Melan A, and MiTF in the immunistochemical workup. FISH testing for t(12;22) and t(X;18) can aid in the diagnosis of clear cell sarcoma (of tendon and aponeurosis) and synovial sarcoma, respectively.
I look forward to hearing more about this interesting case.
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