Metal deposition in post-surgical granulomas of the urinary tract

An Expandable Mechanopharmaceutical Device (2): Drug Induced Granulomas Maximize the Cargo Sequestering Capacity of Macrophages in the Liver

PURPOSE

Drug-induced liver injuries (DILI) comprise a significant proportion of adverse drug reactions leading to hospitalizations and death. One frequent DILI is granulomatous inflammation from exposure to harmful metabolites that activate inflammatory pathways of immune cells of the liver, which may act as a barrier to isolate the irritating stimulus and limit tissue damage.

METHODS

Paralleling the accumulation of CFZ precipitates in the liver, granulomatous inflammation was studied to gain insight into its effect on liver structure and function. A structural analog that does not precipitate within macrophages was also studied using micro-analytical approaches. Depleting macrophages was used to inhibit granuloma formation and assess its effect on drug bioaccumulation and toxicity.

RESULTS

Granuloma-associated macrophages showed a distinct phenotype, differentiating them from non-granuloma macrophages. Granulomas were induced by insoluble CFZ cargo, but not by the more soluble analog, pointing to precipitation being a factor driving granulomatous inflammation. Granuloma-associated macrophages showed increased activation of lysosomal master-regulator transcription factor EB (TFEB). Inhibiting granuloma formation increased hepatic necrosis and systemic toxicity in CFZ-treated animals.

CONCLUSIONS

Granuloma-associated macrophages are a specialized cell population equipped to actively sequester and stabilize cytotoxic chemotherapeutic agents. Thus, drug-induced granulomas may function as drug sequestering "organoids" -an induced, specialized sub-compartment- to limit tissue damage.

Characterization of foreign materials in paraffin-embedded pathological specimens using in situ multi-elemental imaging with laser spectroscopy

Pathologists typically encounter many disparate exogenous materials in clinical specimens during their routine histopathological examinations, especially within the skin, lymph nodes, and lungs. These foreign substances may be free extracellular deposits or induce several clinical abnormalities or histopathological patterns. However, pathologists almost never investigate or report the chemical nature of exogenous metals in clinical specimens due to a lack of convenient and available technologies. In this paper, a novel strategy based on laser-induced breakdown spectroscopy (LIBS) technology is evaluated for in situ multi-elemental tissue imaging. The improved procedures allow visualization of the presence of chemical elements contained within paraffin-embedded specimens of medical interest with elemental images that are stackable with conventional histology images. We selected relevant medical situations for which the associated pathology reports were limited to the presence of lymphohistiocytic and inflammatory cells containing granules (a granuloma and a pseudolymphoma) or to lymph nodes or skin tissues containing pigments or foreign substances. Exogenous elements such as aluminum, titanium, copper, and tungsten were identified and localized within the tissues. The all-optical LIBS elemental imaging instrument that we developed is fully compatible with conventional optical microscopy used for pathology analysis. When combined with routine histopathological analysis, LIBS is a versatile technology that might help pathologists establish or confirm diagnoses for a wide range of medical applications, particularly when the nature of external agents present in tissues needs to be investigated.

Uterine granulomas: clinical and pathologic features

We retrospectively studied the clinical and pathologic features of uterine granulomas over a 10-year period. Granulomas were detected in 30 women, 22 to 81 years old, in the cervix (n = 12/1,090 cervical specimens; 1.1%) or uterine corpus (n = 18/12,000 uterine specimens; 0.15%). They were discovered during evaluation of abnormal bleeding, cytologic specimens, or other gynecologic conditions. None of the patients had constitutional symptoms. These granulomas were often focal (n = 25 [83%]), exhibiting features of foreign body-type (n = 17 [68%]); or they were diffuse (n = 5 [17%]), all with negative acid-fast bacilli or fungal stains and sometimes necrotizing (2 [40%]). Focal granulomas were highly associated with a preceding biopsy or surgery (22/25 vs 14/53 age-matched control subjects). Follow-up of 28 patients (median, 16 months) showed that 27 remained healthy; only 1 patient developed generalized lesions consistent with sarcoidosis 16 months later Uterine granulomas are rare. They are eitherfocal, related to previous biopsy or surgery, or diffuse, usually representing local reaction without an obvious cause. Association with infection or systemic granulomatous disorders is uncommon.

Morphological changes in hysterectomies after endometrial ablation

Electrosurgical ablation of the endometrium is a therapeutic choice for those patients having abnormal uterine bleeding. When ablation is followed by a hysterectomy, tissue damage due to thermal effect can be seen. From a total of 350 women with endometrial ablation, 12 required subsequent hysterectomy. The histological features found in these specimens are described and related to the elapsed time between the two surgical procedures. The mean elapsed time between ablation and hysterectomy was 19 +/- 17.3 months. Scarring with formation of additional endometrial cavities was seen in five cases, and endocervical stenosis in two cases. In seven patients, endometrial regrowth was seen at hysterectomy. Necrosis, granulomatous and foreign-body giant cell reaction, eosinophilic infiltrate and pigment-containing macrophages in the myometrium were seen in the long-term post-ablation hysterectomies. Necrosis was seen in short period post-ablation hysterectomies. Six of the seven patients with endometrial regeneration had adenomyosis in the hysterectomy specimen. Endometrial ablation induces thermal effects in the endometrium and granulomatous reaction with foreign-body giant cell reaction, fibrosis and deposition of pigment within macrophages in the myometrium. Adenomyosis is a possible explanation for endometrial regeneration in cases of ablation failure.

Postoperative granulomas of the endometrium: histological features after endometrial ablation

Postoperative granulomas of the male urogenital tract are a well-recognized phenomenon. Similar granulomas have also been described in the uterine cervix, fallopian tube, and other sites after various procedures, as well as in the endometrium after endometrial ablation procedures. Endometrial ablation is a procedure increasingly used by gynecologists to relieve symptoms associated with dysfunctional uterine bleeding. Occasionally, patients will not have a satisfactory result, and some will require subsequent hysterectomy. We describe the pathological findings in the hysterectomy specimens from 15 patients who had previously undergone endometrial ablation. Indications for subsequent hysterectomy included dysmenorrhea (7 patients), menorrhagia (7 patients), dysfunctional uterine bleeding (5 patients), and pelvic pain (4 patients). All patients had varying degrees of fibrosis of the endometrial cavity, with some endometrial cavities completely obliterated by fibrous tissue. Histological examination revealed fibrosis with varying degrees of granulomatous inflammation. The majority of the granulomas were associated with refractile brown hematoidin-like pigment, and most were also associated with uniform black pigment. In 8 cases, areas of faintly eosinophilic, homogenous, hyalinized material were present within the endometrium. Comparison is made to granulomas due to other causes, because the postoperative granulomas of the endometrium differ morphologically from granulomatous inflammation caused by other etiologies. As endometrial ablation gains popularity among gynecologists and their patients, it is likely that the practicing pathologist may encounter these sequelae with increasing frequency.

The pathology of hysterectomy specimens following trans-cervical resection of the endometrium

The pathological findings in 29 hysterectomy specimens from a series of 175 patients undergoing trans-cervical resection of the endometrium are presented. In all but one case endometrium was present. Although all phases of the normal menstrual cycle were represented, in nine (28%) cases the endometrium appeared inactive, sometimes showing appearances similar to those in Asherman's syndrome. Adenomyosis was present in five (17%) cases and simple hyperplasia in one case. Haematocolpos was present in two cases. Inflammation was uncommon, usually mild in degree and present in the superficial myometrium. Four (14%) cases contained epithelioid or foreign body granulomas in the superficial myometrium. Deposits of haemosiderin and amorphous brown and/or particulate black pigment were seen in a total of 20 (69%) cases. A combination of transmission electronmicroscopy and energy dispersive analysis of X-rays showed these pigments to be a combination of charred organic material and metals, the latter corresponding to the composition of the diathermy cutting loop and electrocautery rollerball used in the ablative surgery.

Pelvic lymph node histiocytosis mimicking metastatic prostatic adenocarcinoma: association with hip prostheses

PURPOSE

Histological changes in lymph nodes simulating metastatic prostatic adenocarcinoma are reported.

MATERIALS AND METHODS

Lymph node frozen sections from 3 patients with prostatic cancer displayed marked histiocytosis. This tissue was subjected to histochemical, immunohistochemical and electron microscopic studies.

RESULTS

Only 1 erroneous diagnosis of metastasis was made. All patients had hip prostheses for at least 6 years. Tissue replacing up to 80% of lymph nodes consisted of histiocytes containing large amounts of polyethylene.

CONCLUSIONS

Hip replacement predisposes the patient to have pelvic lymph node histiocytosis mimicking metastatic adenocarcinoma. This history should be communicated to the pathologist. Polyethylene is the most important factor in the cause of post-prosthesis lymph node histiocytosis.