Indian Journal of Pathology and Microbiology

: 2018  |  Volume : 61  |  Issue : 1  |  Page : 159--161

Clear cell myeloma artefactual or real

Vinita Pandey1, Yasmeen Khatib1, Archana Laxman Khade2, Rahul Pandey3, Manisha S Khare2,  
1 Department of Pathology, HBT Medical College and Dr. R N Cooper Hospital, Mumbai, Maharashtra, India
2 Department of Pathology, HBT Medical College and Dr. R N Cooper Municipal General Hospital, Mumbai, Maharashtra, India
3 Department of Pathology, Tata Memorial Hospital, Mumbai, Maharashtra, India

Correspondence Address:
Archana Laxman Khade
Department of Pathology, C Wing, 1st Floor, Hospital Building, HBT Medical College and Dr. R N Cooper Municipal General Hospital, Juhu, Mumbai - 400 056, Maharashtra

How to cite this article:
Pandey V, Khatib Y, Khade AL, Pandey R, Khare MS. Clear cell myeloma artefactual or real.Indian J Pathol Microbiol 2018;61:159-161

How to cite this URL:
Pandey V, Khatib Y, Khade AL, Pandey R, Khare MS. Clear cell myeloma artefactual or real. Indian J Pathol Microbiol [serial online] 2018 [cited 2023 Sep 29 ];61:159-161
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Full Text


Many rare morphological variants of myeloma cells have been described such as clear cells, signet ring cells, monocytoid cells, and pseudogaucher cells, which pose a diagnostic challenge.[1]

We report two unusual cases of multiple myeloma with clear cell morphology. The first case was a 66 year old male who presented with a history of backache of 2 months duration. His Hemoglobin was 9.6g/dl and ESR was 65mm/h. His creatinine was elevated at 1.5 mg/dl.

Computed tomography showed an epidural, soft tissue mass in D2 region associated with a vertebral lytic lesion [Figure 1]a. Microscopic examination of the epidural mass showed a tumor composed of cells with clear to vacuolated cytoplasm with moderate nuclear pleomorphism [Figure 1]b. Some cells showed signet ring morphology. A single cluster of eosinophilic hyaline globules was also noted [Figure 1]c. The differential diagnosis considered was metastatic clear cell carcinoma and plasmacytoma due to the presence of hyaline globules. On immunohistochemistry, the tumor was immunonegative for pancytokeratin and showed strong expression of CD 138 [Figure 1]d. There was monoclonal expression of kappa light chains. Serum protein electrophoresis showed “M” band of 0.32 g % in the gamma region and increased serum IgG on immunoglobulin assay. The bone scan revealed another lytic lesion in the left clavicle. Bone marrow was uninvolved.{Figure 1}

Our second case was a 48 year old male who presented with pancytopenia. Serum protein electrophoresis showed M band of 0.42 g % in the gamma region. The bone marrow aspirate was diluted with blood and showed the presence of few neoplastic plasma cells with classic morphology. The bone marrow biopsy revealed replacement of the entire marrow by sheets of clear cells with finely vacuolated cytoplasm [Figure 2]a and [Figure 2]b. The cells expressed CD 138 and were lambda light chain restricted. On retrospective analysis, it was found that the marrow biopsy was fixed in 10% buffered formalin for less than an hour and then transferred to 10% formic acid for decalcification. This clear cell change was therefore, artefactual owing to poor fixation of the biopsy in formalin.{Figure 2}

Clear cell myeloma was first reported by Chen et al. in 1985 who initially mistook it for liposarcoma.[2] Signet ring change in myeloma can be misinterpreted as metastatic carcinoma.[3] Svec et al.[4] have reported two cases of myeloma with the presence of microvacuolated plasma cells mixed with signet ring cells which were positive for CD138, Kappa light chains and ubiquitin. The pathogenesis of such cytoplasmic vaculation in myeloma cells is attributed to the formation of autophagic vacuoles due to the excessive production of misfolded immunoglobulins. This was further reiterated by high alkaline phosphatase (lysosomal enzyme) score and strong ubiqutin expression in these neoplastic plasma cells.[4]

Our second case showed artefactual clearing owing to underfixation with 10% formalin. Kotru et al.[5] also reported a similar case and hypothesized that such clear cell change was probably due to action of CO2 like gases during the decalcification process on a poorly fixed tissue.

We therefore conclude that plasmacytoma must be included in the differential diagnosis of a clear cell neoplasm and conversely, artefactual cytoplasmic clearing must be ruled out before making a diagnosis of clear cell myeloma as the entity is relatively rare.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.


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