Whipple's disease presenting as weight gain and constipation in a Chinese woman.

BACKGROUND: Whipple's disease is a chronic infection due to Tropheryma whipplei, commonly reported in the Caucasian but not in the Chinese population. CASE PRESENTATION: A 52-year-old female with good past health, was diagnosed with Whipple's disease, presenting with constipation, unintentional weight gain, and fleeting polyarthralgia. Investigations prior to admission showed raised CA125 and computed tomography of the abdomen showed multiple retroperitoneal mesenteric lymphadenopathies. Extensive investigations performed on secondary causes of weight gain were unrevealing. Subsequent PET-CT scan revealed generalized lymphadenopathy involving the left deep cervical, supraclavicular, and retroperitoneal mesenteric area. Excisional biopsy of the left supraclavicular lymph node was performed, with histology showing infiltrations of Periodic acid-Schiff positive foamy macrophages. T. whipplei DNA was detected in her serum, saliva, stool, and lymph node by PCR targeting the 16S ribosomal RNA gene. She was started on intravenous ceftriaxone, and then stepped down to oral antibiotics for a total of 44 months. The recurrence of fever after 12 days of ceftriaxone raised the suspicion of Immune Reconstitution Inflammatory Syndrome (IRIS). Serial imaging showed a gradual reduction in the size of retroperitoneal lymphadenopathies. Literature review on Whipple's disease in the Chinese population identified 13 reports of detectable T. whipplei DNA in clinical specimens. The majority of the cases were pneumonia, followed by culture-negative endocarditis, encephalitis, and skin and soft tissue infection. However, most patients with pneumonia were diagnosed based on next generation sequencing alone, with the resolution of pulmonary infiltrates without adequate duration of antibiotics, suggesting the possibility of colonization instead of infection. The recommendation of long-term doxycycline suppression after treatment may be supported by the slow response of retroperitoneal lymphadenopathies to antibiotics in our patient. CONCLUSIONS: Unintentional weight gain and constipation could be atypical presentations of Whipple's disease. It is a rare disease in the Chinese population despite the advancement of molecular techniques in the diagnosis of infections. A prolonged course of antibiotics may be required due to slow clinical response as documented by serial imaging in our case. The possibility of IRIS should be considered in patients with breakthrough fever during treatment of Whipple's disease.

T-cell/histiocyte-rich diffuse large B-cell lymphoma. Report of a case diagnosed by fine needle aspiration biopsy with immunohistochemical and molecular pathologic correlation.

BACKGROUND: T-cell-rich B-cell lymphoma (TCRBL) is a lymphoma of B-cell type associated with a prominent component of T cells (constituting > 50% of the cellular population). We report the first case of TCRBL diagnosed by fine needle aspiration (FNA). It was confirmed by subsequent lymph node excision biopsy. CASE: A 37-year-old woman presented with a short history of chest wall pain. Examination revealed induration, warmth and armorlike swelling of the right anterior chest wall, axilla and upper arm, with matted lymph nodes in the ipsilateral axilla and supraclavicular fossa. FNA showed a polymorphic, lymphoid aspirate, among which were many small lymphocytes, significant numbers of centroblastlike cells and a few markedly atypical lymphoid cells with convoluted nuclei. Histiocytes, freely lying karyorrhectic debris and mitotic figures were readily identified. Plasma cells, eosinophils and Reed-Sternberg cells were not seen. The cell block contained similar cells, with larger lymphoid cells scattered among smaller lymphocytes. Immunohistochemical studies showed that the larger cells were B cells. Molecular studies on the cell block confirmed an immunoglobulin gene rearrangement. CONCLUSION: TCRBL is a distinct type of lymphoma that can be accurately diagnosed by FNA.