View source for WBR0803

 {{WBRQuestion
|QuestionAuthor=[[User:Gonzalo Romero|Gonzalo A. Romero, M.D.]] [mailto:gromero@wikidoc.org]
|ExamType=USMLE Step 2 CK
|MainCategory=Internal medicine
|SubCategory=Dermatology, Oncology
|MainCategory=Internal medicine
|SubCategory=Dermatology, Oncology
|MainCategory=Internal medicine
|SubCategory=Dermatology, Oncology
|MainCategory=Internal medicine
|MainCategory=Internal medicine
|MainCategory=Internal medicine
|SubCategory=Dermatology, Oncology
|MainCategory=Internal medicine
|SubCategory=Dermatology, Oncology
|MainCategory=Internal medicine
|SubCategory=Dermatology, Oncology
|MainCategory=Internal medicine
|SubCategory=Dermatology, Oncology
|MainCategory=Internal medicine
|SubCategory=Dermatology, Oncology
|MainCategory=Internal medicine
|MainCategory=Internal medicine
|SubCategory=Dermatology, Oncology
|Prompt=A 55-year-old man with darker skin is admitted to the hospital due to abdominal pain.  The ER doctor orders lab tests and a CT scan, which shows multiple liver metastasis.  On physical examination he does not have a toe; he says it was removed at the age of 20 for a tumor on the nail bed.  The patient is admitted to the hospital.  The internal medicine and oncology team tries to identify the primary tumor ordering a CXR and other diagnostic studies without any success.   Which of the following is the most likely primary tumor?
|Explanation=Most likely this patient developed an acral lentiginous melanoma, a kind of lentiginous skin melanoma.  Melanoma is a potentially serious skin cancer that arises from pigment cells (melanocytes). Although acral lentiginous melanoma is rare in Caucasians and people with lighter skin types, it is the most common subtype in people with darker skins.  Acral lentiginous melanoma is observed on the palms, soles, under the nails and in the oral mucosa. It occurs on non hair-bearing surfaces of the body which may or may not be exposed to sunlight. It is also found on mucous membranes. Unlike other forms of melanoma, acral lentiginous melanoma does not appear to be linked to sun exposure.  Final treatment might require wider excision (margins of 0.5 cm or more), digital amputation, lymphangiogram with lymph node dissection, or chemotherapy. 
Malignant melanoma has this time interval.  After removal there is still a chance of metastasis to usual places (i.e. lymph nodes, liver, lung, brain and bone) and also has capacity of metastasizing to unique places.  Melanoma is a very aggressive tumor that can metastasis even after removed.
|AnswerA=Osteosarcoma
|AnswerAExp=Osteosarcoma is the most common type of malignant bone cancer, accounting for 35% of primary bone malignancies. There is a preference for the metaphyseal region of tubular long bones. 50% of cases occur around the knee. It is a malignant connective (soft) tissue tumor whose neoplastic cells present osteoblastic differentiation and form tumoral bone.
|AnswerB=Rhabdomyosarcoma
|AnswerBExp=A rhabdomyosarcoma is a type of cancer, specifically a sarcoma (cancer of connective tissues), in which the cancer cells are thought to arise from skeletal muscle progenitors. It can also be found attached to muscle tissue, wrapped around intestines, or anywhere, to include the neck area. It is most common in children ages one to five, and teens aged 15 to 19, although quite rare in the latter. It can be a cardiac manifestation of tuberous sclerosis.
|AnswerC=Angiosarcoma
|AnswerCExp=Hemangiosarcoma is a rare, rapidly growing, highly invasive variety of cancer. It is a blood-fed sarcoma; that is, blood vessels grow directly into the tumor and it is typically filled with blood. A frequent cause of death is the rupturing of this tumor, causing the victim to rapidly bleed to death.
|AnswerD=Melanoma
|AnswerDExp=See overall explanation
|AnswerE=Lymphoma
|AnswerEExp=Lymphoma is a type of cancer that originates in lymphocytes (a type of white blood cell in the vertebrate immune system). There are many types of lymphoma.  It can metastasize to the liver, but  night sweats, weight loss and fever symptoms are not mentioned in the history.
|EducationalObjectives=# Melanoma is a very aggressive tumor that can metastasis even after removed
# Acral lentiginous melanoma is observed on the palms, soles, under the nails and in the oral mucosa and is more frequent in blacks and asians
|References=[[Melanoma]]
|RightAnswer=D
|WBRKeyword=melanoma, metastasis, liver metastasis
|Approved=No
}}