We have posted updates of the following topics:
Bone & joints > Chondrosarcoma > Chondrosarcoma (primary, secondary, periosteal)by Akif K. Guney, M.D., Shadi Qasem, M.D.
Topic summary: Locally aggressive or malignant group of tumors characterized by formation of cartilaginous matrix. Primary: arising without a benign precursor. Secondary: arising in preexisting enchondroma or preexisting cartilaginous cap of an osteochondroma. Periosteal: occurs on the surface of the bone in association with the periosteum. Histologic grade, extracompartmental spread and local recurrence are important prognostic factors. Accounts for ~20% of all malignant bone tumors. Most common sites are the pelvic bones, femur and humerus. Pain, local swelling and enlarging mass are the most common presenting symptoms. Diagnosis of chondrosarcoma can be made on imaging studies (Xray, CT scan, MRI) in combination with biopsy specimen. Wide surgical resection is the mainstay of treatment.
Bone marrow neoplastic > Bone marrow – neoplastic myeloid > Myeloid / lymphoid neoplasms with eosinophilia and gene rearrangement > PCM1-JAK2
by Monika Nageshwar, M.B.B.S., M.D., Zeba N. Singh, M.B.B.S., M.D.
Topic summary: PCM1-JAK2 fusion is a rare genomic abnormality resulting from t(8;9)(p22;p24.1), which fuses the Janus activated kinase 2 gene (JAK2) with the human autoantigen pericentriolar material gene 1 (PCM1), resulting in a constitutively activated tyrosine kinase. Morphology usually like an MPN, MDS / MPN or acute leukemia, both myeloid and lymphoid. Sites: peripheral blood and bone marrow. Diagnosis: review of the CBC and peripheral smear evaluation; if eosinophilia is present, all secondary causes of eosinophilia should be excluded clinically and by appropriate investigation. Neoplasms resulting from –PCM1-JAK2 mutation do not respond to imatinib; the JAK1/2 inhibitor ruxolitinib has shown good response, although eventually these patients require allogenic stem cell transplantation.
Lymphoma & related disorders > HHV8 associated lymphoproliferative disorders > HHV8 related germinotropic lymphoproliferative disorder
by Jayalakshmi Venkateswaran, M.D., Julie Teruya-Feldstein, M.D.
Topic summary: Monotypic HHV8 positive lymphoproliferative lesion occurring characteristically in HIV negative patients. Coinfection of HHV8 and EBV. No known epidemiological association. Uncertain contribution of EBV in pathogenesis. Localized, sometimes multifocal lymphadenopathy in otherwise healthy individuals. Very few descriptions of radiological features reported so far. Overall favorable response to chemotherapy and radiation. Treatment approach is variable; some cases have not been treated, while others have been treated with surgery alone or with chemotherapy and radiation.
Lymphoma & related disorders > Mature T/NK cell disorders > Intestinal > Indolent T lymphoproliferative disease of the GI tract
by Anamarija M. Perry, M.D.
Topic summary: Clonal T cell lymphoproliferative disorder (T-LPD) that involves the mucosa of gastrointestinal (GI) tract. Rare, approximately 50 reported cases; most commonly diagnosed in fifth and sixth decade, with a broad age range (23 – 79 years). Generally involves small intestine and colon but any GI site can be involved. Most common presenting symptoms are abdominal pain and diarrhea. Diagnosis: biopsy of affected GI site. No specific prognostic factors identified. Poor response to conventional chemotherapy and immunotherapy; so far, there is no successful treatment.
Uterus > Smooth muscle tumors > Leiomyoma-general
by Léonie Alran, B.S., Agnieszka Rychlik, M.D., Sabrina Croce, M.D., Ph.D.
Topic summary: Most common uterine tumor. Benign mesenchymal tumor derived from smooth muscle. All ages, especially in fifth decade; third decade for fumarate hydratase deficient leiomyoma. Sites: uterine corpus; less common in vulva, vagina, cervix, broad ligament, ovary. Mitotically active leiomyoma: associated ischemia or hormonal stimulation (endogenous or exogenous). Diagnosis can be established by resection of the whole uterus (hysterectomy), by resection of the leiomyoma if accessible by curetting (if submucosal) or by myomectomy (if subserosal). Asymptomatic: does not require therapy. Symptomatic leiomyoma: surgery (hysterectomy or myomectomy); hysteroscopic resection.
