Mycobacterium leprae in bone marrow

The case of a 54-year-old man, who was referred to evaluate a consumptive syndrome with anemia and fever of unknown origin, is reported. A physical examination revealed madarosis, nodular lesions on the ears, nasal soft tissue collapse, subcutaneous nodules on arms and generalized lymphadenopathy. Laboratory tests showed anemia (Hb 8.8 g/dL, mean corpuscular volume 82.4 fL, mean corpuscular hemoglobin 24.5 pg), normal reticulocyte count (0.5%), thrombocytosis (482 × 10⁹/L), normal serum ferritin (268 ng/mL) and elevated C-reactive protein (124 mg/L). Serologies (viral hepatitis and human immunodeficiency virus) were non-reagent. Lepromatous leprosy was confirmed by staining for acid-fast bacilli using samples from the ear and subcutaneous nodules and bone marrow smears. Bone marrow was hypercellular with myeloid hyperplasia (myeloid-erythroid ratio 7:1) but without dysplasia. Mycobacterium leprae was detected lying free and in foamy histiocytes named Virchow cells ( Figure 1 and Figure 2). ^{1 and 2} A multidrug therapeutic regimen (clofazimine, dapsone, rifampicin) was established with progressive improvement.

Figure 1
Large cells (histiocytes) with their abundant cytoplasm filled with acid-fast bacilli (Mycobacterium leprae) in bone marrow (Ziehl-Neelsen stain) magnification 1000×.

Figure 2
Large cells (histiocytes) with their abundant cytoplasm filled with acid-fast bacilli (Mycobacterium leprae) in bone marrow (Fite-Faraco stain) magnification 1000×.

REFERENCES

• ¹
  Singh N, Bhatia A, Lakra A, Arora VK, Bhattacharya SN. Comparative cytomorphology of skin, lymph node, liver and bone marrow in patients with lepromatous leprosy. Cytopathology. 2006;17:257-61.
• ²
  Suster S, Cabello-Inchausti B, Robinson MJ. Non-granulomatous involvement of the bone marrow in lepromatous leprosy. Am J Clin Pathol. 1989;92:797-801.

Publication Dates

• Publication in this collection
  Jul-Aug 2014

History

• Received
  04 Mar 2014
• Accepted
  17 Mar 2014