Compound Heterogeneous Sickle Cell-B+ Thalassemia Incidentally Discovered Through Cytological Examination of a Fine-Needle Aspiration Specimen from an Aneurysmal Bone Cyst in a Young Child: A Case Report

Abstract

Sickle cell beta-thalassemia (S/β) is a rare inherited variant of sickling disorders, usually occurring due to the inheritance of two abnormal genes, namely, the sickle cell gene, and the beta-thalassemia gene. There are two types of sickle cell β-thalassemia: (S/β+) and (S/β0), based on a decrease or complete absence of beta-globin synthesis, respectively. Skeletal complications, such as osteonecrosis, osteomyelitis, and septic arthritis, are well-known sequelae in sickle cell patients due to vaso-occlusive events. Nevertheless, the occurrence of aneurysmal bone cysts in patients with sickle cell hemoglobinopathy is an exceptional phenomenon. Herein, we report a case of a young boy who presented with nonspecific clinical symptoms over a few years. The patient was referred to our institution as a case of short stature with recurrent joint pain. A clinical workup was done and an aneurysmal bone cyst (ABC) of the left humerus was discovered radiologically with incidental detection of sickle cells through cytological evaluation of the cyst fluid. Further clinical investigation, including molecular and additional laboratory tests, confirmed the diagnosis of compound heterogeneous sickle cell-B+ thalassemia. Unfortunately, neither was the underlying pathology detected nor was the precise clinical diagnosis attained at the outside primary healthcare facility.

Keywords: aneurysmal bone cyst; fine needle aspiration; hemoglobinopathies; sickle cell crisis; sickle β thalassemia.

Figure 1. Plain X-ray of the left humerus

Cystic lesion of the left upper humerus (arrow)

Figure 2. Diff-Quick cytology preparation (at 20x)

Many sickle cells (arrow) in a lymphocyte-rich background rich admixed with a few histiocytes and rare plasma cells