Malakoplakia as a cause of severe hypercalcemia through ectopic 25-hydroxyvitamin D3 1-alpha-hydroxylase expression: A case report.

RATIONALE: Malakoplakia is a rare disease characterized by the presence of nongranulomatous macrophage infiltration. In most cases, it affects the urinary tract. Malakoplakia can cause acute kidney injury when it is localized in the kidneys. PATIENT CONCERNS: Here, we report the case of a 65-year-old female patient with renal malakoplakia responsible for hypercalcemia. During her initial assessment, she was also diagnosed 25-OH vitamin D insufficiency, for which she was prescribed oral cholecalciferol. Three months later, she developed severe hypercalcemia with normal 25-OH vitamin D and parathyroid hormone levels and high 1,25-dihydroxyvitamin D levels. DIAGNOSES: After a superimposed granulomatous disease was excluded, malakoplakia cells were suspected to be responsible for the abnormal 25-hydroxyvitamin D3 1-alpha-hydroxylase activity, which was confirmed by immunohistochemistry. INTERVENTIONS: Cholecalciferol was stopped, the patient was rehydrated with intravenous physiological saline, and prednisone was initiated to decrease the enzyme activity. OUTCOMES: Six months later, she displayed normal serum calcium, 25-OH vitamin D and 1,25-dihydroxyvitamin D levels. LESSONS: This case illustrates that malakoplakia may exhibit ectopic 25-hydroxyvitamin D3 1-alpha-hydroxylase activity and cause severe hypercalcemia upon vitamin D supplementation. Therefore, such supplementation should not be given in malakoplakia patients without an actual deficiency and requires careful monitoring of serum calcium.

Malakoplakia of the Urinary Bladder in a Patient with Chronic Lymphocytic Leukemia Under Ibrutinib Therapy: A Case Report.

Malakoplakia, a rare granulomatous disease of infectious etiology, is commonly observed in immunocompromised patients. Chronic lymphocytic leukemia (CLL) is characterized by profound immune dysregulation resulting in significant infection-related morbidity and mortality, and several drugs used in CLL treatment have a severe immunosuppressive effect. Ibrutinib, has become a new standard-of-care in patients with CLL, especially for those harboring unfavorable genetic characteristics such as 17 p deletion, with however, unknown long-term immunological consequences. Here we report a case of a patient with CLL with 17 p deletion diagnosed with malakoplakia of the urinary bladder under ibrutinib therapy who developed severe hypogammaglobulinemia during treatment administration. Presumably, ibrutinib might contribute to the development of malakoplakia on the grounds of induced immunosuppression. This case report highlights the need for regular assessment of immunogammaglobulin adequacy during treatment with ibrutinib, considering that it should be given on a permanent basis.

Primary non-Hodgkin's lymphoma and malakoplakia of the vagina: a case report.

The vagina is a rare site for both primary non-Hodgkin's lymphoma and malakoplakia. We report a case of concurrent diffuse large B-cell lymphoma and malakoplakia of the vagina in a 67-year-old woman presenting with a vaginal discharge and a vaginal mass. The patient had two biopsy specimens reported as showing malakoplakia only, followed by a third biopsy specimen 10 months later which was diagnosed as diffuse large B-cell lymphoma. Review of the first two biopsy specimens showed areas of histiocytes with Michaelis-Gutman bodies merging with areas of cells with slightly larger nuclei and more amphophilic cytoplasm. Immunohistochemistry for the B-cell marker L-26 (CD20) and polymerase chain reaction analysis of the immunoglobulin heavy chain gene were helpful in retrospectively distinguishing the population of diffuse large B-cell lymphoma from the areas of malakoplakia. The third biopsy specimen showed sheets of large atypical lymphoid cells characteristic of a large cell lymphoma. Malakoplakia has been described in association with a variety of cancers, and this is only the second report of malakoplakia associated with non-Hodgkin's lymphoma. Considering the rarity of these two entities in the vagina, it is unlikely that the association in this case is coincidental, raising the possibilities of an unusual reaction to the presence of lymphoma or a common pathogenesis such as underlying chronic inflammation. Epstein-Barr virus DNA was detected in the second biopsy specimen, suggesting a possible role in the pathogenesis of this lymphoma.

Colonic malacoplakia--occurrence in a family. Report of cases.

A family with two cases of documented colonic malacoplakia is reported. Details regarding the younger sister have been published previously and those of the elder are reported in this paper. Two brothers were found to have strongly positive purified protein derivative and histologic evidence of nonspecific colitis, but without clinical, endoscopic, or histopathologic evidence of malacoplakia. The parents are first cousins and have a total of 13 children. A computer search of the literature revealed no previous reports on familial occurrence of this disease. Thus, the authors consider this to be the first report of malacoplakia in siblings of the same family and suggest adding genetic predisposition in the pathogenesis of the disease.