Bone marrow aspirate:

Hypercellular marrow for age with infiltration of large histiocytes with eccentric nuclei and a fibrillar, "onion-skin" cytoplasm in keeping with Gaucher cells. There was a slight increase in erythropoiesis with mild dyserythropoiesis but granulopoiesis and megakaryopoiesis were normal in number and maturation. These findings would be supportive of a diagnosis of Gaucher's Disease.

Bone marrow trephine:

The bone marrow trephine is moderately cellular with a prominent population of plump histiocytes. These cells have small, uniform nuclei and abundant pale cytoplasm that has a striated appearance. This material is weakly positive for diastasePAS. These are typical Gaucher cells. The remaining haemopoietic elements are somewhat obscured but appear normal. There is a mild increase in reticulin; there is moderate iron (also seen in some Gaucher cells); the bony trabeculae appear normal.

Splenic core biopsy: (smaller inferior lesion biopsied under US guidance, proximal lesion not accessible)

Microscopic Description: Spleen. Sections show plentiful single and aggregated large histiocytes with copious often eccentric granular and fibrillary eosinophilic cytoplasm and often irregularly indented and elongated small nuclei in the red pulp of the spleen. There are only occasional similar cells in the white pulp. There is no evidence of malignancy. Comment: the features are those of Gaucher's disease. FIRST SUPPLEMENTARY: Gaucher's cells are positive in the PAS and DiPAS stains and variably weakly positive in the iron stain. The CD163 immunoperoxidase stain is positive around the cytoplasmic rim of the plump histiocytes.

Appendix specimen:

Microscopic Description: Appendix. Sections of the appendix show acute on chronic transmural inflammation extending to the subserosa. No granulomas or pathogens are identified. The inflammation extends into the mesoappendix, which shows conspicuous fat necrosis. The appearances are those of acute on chronic appendicitis and serositis. There is reactive epithelial atypia; however, there is no dysplasia or malignancy.