Black bone marrow aspirate

H Mirfazaelian¹, A Rezvani², Y Daneshbod³,  
¹ Department of Emergency Medicine, Tehran University of Medical Sciences, Tehran, Iran
² Department of Hematology-Oncology, Shiraz University of Medical Sciences, Shiraz, Iran
³ Department of Hematopathology, Dr. Daneshbod Pathology Laboratory, Shiraz, Iran

Correspondence Address:
H Mirfazaelian
Department of Emergency Medicine, Tehran University of Medical Sciences, Tehran
Iran

Full Text

Sir,

A 61-year-old man presented with anorexia and 2 weeks of abdominal pain. On physical examination, there was only mild right upper quadrant abdominal tenderness with no organomegaly. There was a past medical history of Hodgkin's disease (HD), mixed cellularity type (stage IV), which was on remission since 5 years ago after chemotherapy with unknown regimen without any radiation therapy.

The laboratory results were significant for only lactate dehydrogenase level, which was 1000 IU/L with mild normocytic anemia. On his abdominal computed tomography scan with intravenous contrast, there was a mildly enlarged liver with numerous enhancing and non-enhancing hypodense foci. The diagnosis of probable HD relapse with liver involvement was made. Liver biopsy and bone marrow aspiration and biopsy were undertaken. Interestingly, a dark tinged aspirate was obtained in bone marrow aspiration. The smears showed polymorphic population of normal hematopoietic cells with darkly pigmented cells [Figure 1]a and b. Bone marrow biopsy revealed polymorphic normocellular marrow with solitary and clusters of dark pigmented cells with prominent nucleoli [Figure 1]c. Iron stain carried out on smears and trephine biopsy was negative in the pigments, which proved the cells as non-Hemosiderin laden macrophages. Immunoperoxidase staining showed strong and diffuse positivity for S100 protein, Human Melanoma Black (HMB)-45, Melan-A, and negative for cytokeratin, epithelial membrane antigen, CD45, and CD30 which is characteristic for malignant melanoma. On liver biopsy, there was diffuse infiltration by large pigmented malignant cells with prominent eosinophilic nucleoli. After bleaching, the pigments disappeared, a finding in favor of melanin pigments. Immunoperoxidase proved that this tumor was also melanoma. A thorough search for finding the origin of this new malignancy was performed (including nasal, mucosal, and ophthalmologic examinations), which was futile.{Figure 1}

Malignant melanoma accounts for 1-3% of all malignancies with an increasing incidence being seen worldwide with lung most commonly involved in metastatic disease. [1] While epithelial tumors of the thyroid, breast, lung, kidney, and prostate commonly metastasize to the marrow, melanoma metastatic infiltration can be diagnosed in 5-7% of patients with disseminated disease (usually amelanotic). [2],[3],[4] Anemia is the most common hematologic manifestation followed by thrombocytopenia, pancytopenia, and leukoerythroblastosis. These changes have been attributed to different causes such as bone marrow invasion, tumor mediators, and autoimmunity. [1] Although primary tumor is obvious most of the times, it might have regressed over the period of time in the index patient. While partial regression is a common feature, in about 5-15% of cases, metastatic melanoma is detected in the absence of an identifiable primary site. [1] In immunohistochemistry, melanin usually reacts with vimentin, S-100 protein, HMB-45 (more specific than S-100), melan-A, tyrosinase, and microphthalmia transcription factor. [1] Although HD can coincide with melanoma, radiotherapy is considered as one of risk factors for melanoma formation and its diagnosis after HD treatment has been reported previously. [5] This patient had not received radiotherapy in his regimen. So, it can be proposed that radiation is not the sole risk factor and one should also consider factors such as chemotherapy and genetic predisposition factor for this ominous event.

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