Abdominal Lymphadenopathy: Hypothesize Cat-Scratch Disease and Avoid Abdominal Excisional Biopsy

Round 1

Reviewer 1 Report

The paper is well written, properly documented and the reading is easy. It describes the unusual localization of cat scratch disease as abdominal lymphadenopathy and illustrates the diagnostic course taken, which avoided invasive biopsy of an abdominal lymph node, performing it on a superficial inguinal lymph node with similar characteristics. In conclusion, this report suggests that SCD should also be considered in the differential diagnosis of abdominal lymphadenopathy with fever, chills and abdominal lymphadenopathy but limited to a few lymph nodes. 

However, the differential diagnosis needs to be more developed in the report, e.g. vs KFD (Kikuchi-Fuijmoto disease), the classic counterpart of SCD. Although KFD with intra-abdominal lymphadenopathy is rare, it should be considered in young adults with intra-abdominal lymphadenitis.  

Author Response

We would like to thank the reviewer for her/his productive recommendations: your comments surely gave us the opportunity to improve the quality of our manuscript.

Please, you can find below a reply to your comments (Authors’ reply is written in bold,) and we enclosed our revised manuscript version. We hope we’ve adequately answered to your question giving clear and shared answer. We refer to your reliable opinion to know if this revised version has reached the necessary requirements to be published or if there are further issues to be clarified and improved.

Thank you very much once again for your precious availability.

Best regards,

Francesca Maccioni

 

Reviewer 1.

The paper is well written, properly documented and the reading is easy. It describes the unusual localization of cat scratch disease as abdominal lymphadenopathy and illustrates the diagnostic course taken, which avoided invasive biopsy of an abdominal lymph node, performing it on a superficial inguinal lymph node with similar characteristics. In conclusion, this report suggests that SCD should also be considered in the differential diagnosis of abdominal lymphadenopathy with fever, chills and abdominal lymphadenopathy but limited to a few lymph nodes. 

However, the differential diagnosis needs to be more developed in the report, e.g. vs KFD (Kikuchi-Fuijmoto disease), the classic counterpart of SCD. Although KFD with intra-abdominal lymphadenopathy is rare, it should be considered in young adults with intra-abdominal lymphadenitis.  

We thank the Reviewer for his/her suggestion. The lymph node histologic findings were characterized by well-defined granuloma with suppurative necrosis and abundant granulocytes, consistent with the suspicion of CSD. Crescentic histocytes or clusters of plasmacytoid dendritic cells, which are the histological hallmark of KFD were not present. We added few sentences about the histologic differential diagnosis between Cat Screech Disease and KFD in the revised manuscript (at the end of “Case report” section).

Reviewer 2 Report

The manuscript of Filipponi et al. may be of interest but needs further work.

1.       Cat-scratch disease is a rather rare condition, which is usually diagnosed by combining clinical and pathological data. Thus, it is inappropriate to suggest a wait and see policy in case of a TAC-positive/PET-positive deep lymphadenopathy (which is the present case was associated with an inguinal lump). In fact, there is the risk of a delayed diagnosis of malignant lymphoma or other kind of tumour.

2.       The exact Bartonella IgG titers recorded in the reported case should be shown.

3.       The diagnosis would be significantly supported by a Warthin-Starry silver impregnation carried out in tissue sections as well as by an accurate anamnesis indagating which contact with Bartonella the patient might have had (via domestic animals? following an injury?).

4.       The differential diagnosis with Lymphogranuloma venereum needs to be discussed.

Author Response

We would like to thank the reviewer for her/his productive recommendations: your comments surely gave us the opportunity to improve the quality of our manuscript.

Please, you can find below a point-by-point reply to your comments (Authors’ replies are written in bold,) and we enclosed our revised manuscript version. We hope we’ve adequately answered to all your questions giving clear and shared answers. We refer to your reliable opinion to know if this revised version has reached the necessary requirements to be published or if there are further issues to be clarified and improved.

Thank you very much once again for your precious availability.

Best regards,

Francesca Maccioni

 

Reviewer 2

The manuscript of Filipponi et al. may be of interest but needs further work.

1. Cat-scratch disease is a rather rare condition, which is usually diagnosed by combining clinical and pathological data. Thus, it is inappropriate to suggest a wait and see policy in case of a TAC-positive/PET-positive deep lymphadenopathy (which is the present case was associated with an inguinal lump). In fact, there is the risk of a delayed diagnosis of malignant lymphoma or other kind of tumour.
2. The exact BartonellaIgG titers recorded in the reported case should be shown.

        We thank the Reviewer for his/her suggestion. The Bartonella IgM titer was negative (IgM 0,67, positive if >1.1 antic. index) and IgG titer was positive (IgG 2.81; positive if >1.1 antic. index).

        In our patient, this data was evaluated only retrospectively as added at the “case report” section of the revised manuscript.

 

3. The diagnosis would be significantly supported by a Warthin-Starry silver impregnation carried out in tissue sections as well as by an accurate anamnesis indagating which contact with Bartonella the patient might have had (via domestic animals? following an injury?).

 

        We agree with the Reviewer comments. We performed the Warthin-Starry staining obtaining negative

        results. This is not surprising considering the low sensitivity of the histochemical stain, especially in long lasting lesions, see for example Appl. Immunohistochem. Mol. Morphol. 2020 Nov/Dec;28(10):781-785.

        Unfortunately, specific antibodies for immunistochemical detection of B. henselae on tissue sections are not available in our pathology lab. However a specific anamnestic assessment of exposure to domestic animals (e.g. cats) was done only retrospectively and this is precisely the purpose of this report: hypothesize Cat-Scratch Disease.

        About this issue we added few sentences at the “Case report” and “Discussion and Conclusions ” sections of the revised manuscript.

 

 

4. The differential diagnosis with Lymphogranuloma venereumneeds to be discussed.

 

        We thank the Reviewer for his/her comment. Although suppurative inflammation of inguinal lymph nodes   may be caused by Chlamydia infection, plasma cells infiltrate, which is quite characteristic in case of Chlamydia infection, was absent in the present case.

        We added few sentences on this topic in the “Discussion and Conclusions” section of the revised manuscript.

Round 2

Reviewer 2 Report

The Authors answered most if not all issues addressed.