Extramedullary plasmacytoma mimicking colon carcinoma: an unusual presentation and review of the literature

After two weeks of supportive treatment, the patient’s symptoms began to improve. He continued to Carfilzomib have numerous indurated confluent lesions on his body Carfilzomib and face consistent with KS. His pulmonary symptoms were thought to be due to disseminated KS. Following significant discussions with the patient and his family regarding the poor prognosis of his disease, he decided not to undergo any further antineoplastic treatments and eventually was discharged home with hospice.
Discussion of diagnosis

Kaposi Sarcoma (KS) is an angioproliferative tumor associated with human herpes virus 8 (HHV-8)1,2. It is one of the AIDS-defining skin diseases and is strongly linked to male homosexual behavior3,4. Four clinical variants of KS have been described: classic, African, iatrogenic and AIDS-related5–10. The classic variant mainly affects elderly men of Eastern European Jewish and Mediterranean origin7–9. The African, or endemic type, affects primarily men in the 4th decade of life in East and Central Africa10. Its clinical presentation is similar to the classic form but with a more aggressive variant that responds poorly to conventional treatment10. The third variant, iatrogenic KS, is related to chronic immunosuppressive drugs used in organ-transplant recipients or cancer patients5–10. This variant tends to be more aggressive, involving lymph nodes, mucosa and visceral organs. AIDS-related KS is an aggressive epidemic form that commonly affects patients with immunosuppression from AIDS3–5.

Pulmonary involvement in KS has only been discussed in a handful of case reports, very few of which were in non-HIV patients11–16. This is likely due to the lack of published evidence of KS in general, as well as the presence of multiple co-morbidities in most patients which may mask clear identification of pulmonary KS. In most cases, it occurs in conjunction with more extensive muco-cutaneous disease12–16. Unique manifestations that distinguish KS from other pathologic processes in the lungs have not been identified. The most common characteristics of pulmonary KS include peri-broncho-vascular and nodular opacities, thickened interlobular septa and pleural effusions17–21.

Signs and symptoms such as shortness of breath, hypoxemia, and dry cough are common in pulmonary KS. Hemoptysis, fever, chest pain and respiratory failure can also occur. Additionally, enlarged mediastinal lymph nodes are frequently seen in patients with this disease16–21.

The diagnosis of pulmonary involvement in KS can often be made by a combination of clinical, radiographic and laboratory findings, in conjunction with results of a transbronchial biopsy21,22. Radiographic findings in pulmonary KS are varied and include segregated pulmonary nodules, pleural effusions, and hilar or mediastinal lymphadenopathy, all of which were also evident in our patient23–25. Several polymerase chain reaction (PCR) assays employing primers unique for HHV-8 have been described26,27. Our patient did not match the typical subgroups as HIV infection and other immune disorders were ruled out. Furthermore, it has been shown that KS, in non-HIV patients, clinically resembles classic KS but occurs at a younger age, is limited to the skin, and is associated with a good prognosis5. Our patient, however, demonstrated both dermatologic and pulmonary manifestations suggesting a disseminated and aggressive form of the disease.