Soft tissue sarcoma

Bone tumors range from benign lesions such as osteochondroma and osteoid osteoma to aggressive primary malignancies such as osteosarcoma, chondrosarcoma, and Ewing sarcoma. The diagnostic approach is a radiograph first to characterize the lesion as benign or aggressive, then MRI for local extent, then image-guided biopsy as the confirmatory step, with management ranging from observation to resection and chemotherapy.

Kaposi sarcoma is a human herpesvirus 8-associated vascular malignancy that presents as violaceous macules, papules, plaques, or tumors of the skin, mouth, gastrointestinal tract, or lungs, most often in HIV-associated, transplant-related, or classic elderly disease. Diagnosis is confirmed by biopsy. Every patient with HIV-associated Kaposi sarcoma starts or optimizes antiretroviral therapy, with liposomal doxorubicin 20 mg/m2 intravenously every 21 days added for extensive or visceral disease.

Uterine leiomyomas are benign monoclonal smooth-muscle tumors of the myometrium that cause heavy menstrual bleeding, bulk symptoms, and reproductive dysfunction; management ranges from expectant care to hormonal bleeding control to fertility-sparing or definitive surgery.

Autosomal dominant neurocutaneous disorder from NF1 tumor suppressor mutations causing cafe-au-lait macules, neurofibromas, Lisch nodules, and optic glioma; diagnosed clinically by consensus criteria and managed with surveillance, surgery for symptomatic tumors, and selumetinib for inoperable plexiform neurofibromas.

A lipoma is a benign, freely mobile subcutaneous fat tumor that is diagnosed clinically on the basis of a soft, painless, slowly growing mass and managed with observation unless the lesion is symptomatic, atypical, or the patient requests removal, in which case elective excision is curative. Features that break the typical pattern, size 5 cm or larger, deep or fascial fixation, rapid growth, or unexplained pain, should trigger imaging and specialist evaluation to exclude liposarcoma rather than routine removal.

Lymphedema is chronic tissue swelling from impaired lymphatic drainage, primary (developmental) or secondary (from surgery, radiation, infection, or malignancy). It causes progressive non-pitting edema that involves the toes, and management is decongestive therapy with compression, skin care, and cellulitis prevention, since there is no curative drug.

Five inherited syndromes drive colorectal cancer risk through distinct genes and polyp biology: FAP and MUTYH-associated polyposis through adenomas, Lynch syndrome through mismatch-repair loss, and Peutz-Jeghers and juvenile polyposis through hamartomas. Each carries its own inheritance pattern, surveillance schedule, and threshold for surgery.

Necrotizing fasciitis is a rapidly progressive, life-threatening infection of the subcutaneous tissue and superficial fascia driven by vessel thrombosis and bacterial exotoxin production. The hallmark is pain out of proportion to visible skin findings, with crepitus, bullae, and woody induration in advanced disease. Diagnosis is confirmed by direct surgical exploration; the LRINEC score aids risk stratification. Treatment is emergent surgical debridement combined with broad-spectrum empiric antibiotics.

Cellulitis is a nonpurulent, spreading infection of the deep dermis and subcutaneous fat, usually caused by beta-hemolytic streptococci, diagnosed clinically and treated with antibiotics alone since there is no collection to drain.