Endocrine Perspective of Cutaneous Lichen Amyloidosis: RET-C634 Pathogenic Variant in Multiple Endocrine Neoplasia Type 2

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Comments: Authors addressed an important question in the manuscript but manuscript require attention on following comments

Minor comments:

1.        English language and typos proofreading required attention e.g. line#104 and line#273 ‘caring?’; line#277, scare?

2.      Associated RET mutation reported so far can be tabulated with reference for better understanding of the same.

Major comments:

1)      How Cutaneous lichen amyloidosis was diagnosed. Histopathological findings of skin biopsy is highly recommended to confirm the presence of amyloid protein to rule out other skin conditions.

2)      Cutaneous lesion only present in inter-scapular region? Detail description of same should be provided.

3)      Hormonal levels were not assessed before surgery? Table 2, 3, 4, lacking the data, it will be more informative for readers.

4)      Cutaneous lichen amyloidosis association with multiple endocrine neoplasia type 2 has already been reported.  It has been reported that more than 30% of patients with MEN 2A who have a c634 RET mutation will develop Cutaneous lichen amyloidosis. Cite appropriate references to discuss the same.

5)       Please add the discussion of presence of Primary hyperparathyroidism in MEN 2A vs MEN 2B. Describe the limitations of present case series in this context, if any.

Author Response

  Dear Reviewer,

 Thank you very much for your time and your effort to review our manuscript.

We are very grateful for providing your valuable feedback on the article.

Here is our response and related amendment that has been made in the manuscript according to your review (marked in yellow color).

Comments: Authors addressed an important question in the manuscript but manuscript requires attention on following comments.

Thank you very much. We addressed your recommendations point by point as follows:

 Minor comments:

English language and typos proofreading required attention e.g. line#104 and line#273 ‘caring?’; line#277, scare?

Thank you very much. We corrected them. Thank you.

 Associated RET mutation reported so far can be tabulated with reference for better understanding of the same.

Thank you very much. We presented a new figure to overview these aspects and expanded the genetic data (other than RET-C634). Thank you.

“As exception from the C634, we highlight the study conducted by Qi et al. [36] that identified a case of germline C611Y (c.1832G>A) RET mutation with inter-scapular lichen amid multiple endocrine neoplasia type 2. Of note, long standing pruritus may be present years before the actual development of the lichen, but the actual cause of developing lichen in these patients remains an open issue [36]. The first RET p.C634F pathogenic variant with concern to this combination of endocrine and skin ailments was revealed in a Chinese patient in 2018 [37]. Alternatively, RET-p.S891A associated with OSMR gene (p.G513D) variant has been identified in lichen amyloidosis and familial medullary thyroid carcinoma [38]. The earliest diagnosis of medullary thyroid carcinoma and lichen amyloidosis was reported in 2002 in an asymptomatic 5-year-old child coming from a family with multiple endocrine neoplasia type 2 that harbored RET-Cys634Trp (TGC->TGG) pathogenic variant [39]. (Figure 4)”

Figure 4. Genetic and pathogenic findings in patients with lichen amyloidosis and multiple endocrine neoplasia type 2 [19-20,36-40].

Major comments:

How cutaneous lichen amyloidosis was diagnosed. Histopathological findings of skin biopsy is highly recommended to confirm the presence of amyloid protein to rule out other skin conditions.

Thank you very much. The diagnosis was established by the standard dermatologic exam and further biopsy was declined by the patients (in addition to the fact that, as mentioned, some family members declined the entire endocrine and genetic evaluation at all). This is part of a real-life setting and we addressed this issue at Discussion section (limits of the current case series). Thank you.

 Cutaneous lesion only present in inter-scapular region? Detail description of same should be provided.

Thank you very much. We confirm that only the inter-scapular region was affected. Thank you.

 Hormonal levels were not assessed before surgery? Table 2, 3, 4, lacking the data, it will be more informative for readers.

Thank you very much. We added these data. Thank you for this useful recommendation.

Table 2

Multiple endocrine neoplasia type 2	Medullary thyroid carcinoma	Pheochromocytoma	Primary hyperparathyroidism
Hormonal assays before surgery	Calcitonin=304 ng/mL (normal: 1-4.8)	Plasma metanephrines=300 pg/mL (normal: 0-100)   Plasma normetanephrines=400 pg/mL (normal: 0-216)	PTH=122 pg/mL (normal: 15-65)   Total serum calcium=11.4 mg/dL

 

Table 3

Hormonal assays before surgery

Calcitonin=74 ng/mL (normal: 1-4.8)

Plasma metanephrines=148 pg/mL (normal: 0-90)   Plasma normetanephrines=78 pg/mL (normal: 0-216)

no

 

Tabl4 4

Hormonal assays before surgery

Calcitonin=475 ng/mL (normal: 1-4.8)

Plasma metanephrines=332 pg/mL (normal: 0-90)   Plasma normetanephrines=552 pg/mL (normal: 20-200)

no

 

Cutaneous lichen amyloidosis association with multiple endocrine neoplasia type 2 has already been reported.  It has been reported that more than 30% of patients with MEN 2A who have a c634 RET mutation will develop Cutaneous lichen amyloidosis. Cite appropriate references to discuss the same.

Thank you very much. We expanded these data and already mentioned the new figure. Thank you

 Please add the discussion of presence of Primary hyperparathyroidism in MEN 2A vs MEN 2B.

Thank you very much. According to your recommendations, we added more information with regard to the primary hyperparathyroidism. Thank you

 “Across this case series we found only one patient with primary hyperparathyroidism which is the least frequent component in multiple endocrine neoplasia type 2 and the data we have so far did not confirm a stronger association with the presence of lichen amyloidosis in these patients. Parathyroid tumors have been reported in 0.1-0.3% of the population and 98% of them are benign. Genetic primary hyperparathyroidism represents 2% to 10% of all cases and germline mutations are reported in 10% of type 2A, respectively, 50% of type 2B subjects with multiple endocrine neoplasia. The parathyroid involvement is described later across life span when compare to the medullary thyroid carcinoma and the familial cases harboring RET pathogenic variants should follow lifelong surveillance protocols of PTH and annual calcium assays. Interestingly, RET-C634  represents the most common mutation associated with the identification of the parathyroid tumors, as seen in lichen amyloidosis [49,50].”

49.Marini F, Giusti F, Iantomasi T, Brandi ML. Parathyroid Tumors: Molecular Signatures. Int J Mol Sci. 2021;22(20):11206. doi:10.3390/ijms222011206.

50.Marx SJ, Goltzman D. Evolution of Our Understanding of the Hyperparathyroid Syndromes: A Historical Perspective. J Bone Miner Res. 2019;34(1):22-37. doi:10.1002/jbmr.3650.

 Describe the limitations of present case series in this context, if any.

Thank you very much. We expanded these data at the end of Discussion section. Thank you

 Thank you very much.

 

Reviewer 2 Report

Comments and Suggestions for Authors

This case series offers interesting insights into the relationship between multiple endocrine neoplasia type 2 (MEN2), medullary thyroid carcinoma (MTC) and cutaneous lichen amyloidosis in a family carrying the RET-C634 mutation. However, the presentation could be further refined by implementing the following points:

- Clarify the chronology of each patient's clinical events to improve understanding of case progression.

- Provide more details on long-term follow-up and outcomes, including quality of life after surgery.

- Expanding the discussion on therapeutic approaches for lichen amyloidosis:

e.g. 10.3390/diseases12050094

- Explain the impact of family members' refusal of the genetic test on the overall results.

- Reinforce discussion of potential mechanisms linking RET mutations to lichen amyloidosis.

- Correct minor grammatical errors to ensure clarity and accuracy.

Author Response

Dear Reviewer,

Thank you very much for your time and your effort to review our manuscript.

We are very grateful for your insightful comments and observations, also, for providing your valuable feedback on the article.

Here is a point-by-point response and related amendments that have been made in the manuscript according to your review (marked in yellow color).

This case series offers interesting insights into the relationship between multiple endocrine neoplasia type 2 (MEN2), medullary thyroid carcinoma (MTC) and cutaneous lichen amyloidosis in a family carrying the RET-C634 mutation.

 However, the presentation could be further refined by implementing the following points:

Clarify the chronology of each patient's clinical events to improve understanding of case progression.

Thank you very much. We added a new figure with respect to the timeline. Thank you

 “Figure 4. Chronology of each patient's clinical events (Abbreviations: Ca = calcium supplements; F = fludrocortisone; GC = glucocorticoids; HR = hormone replacement; LT4 = levothyroxine; MTC = medullary thyroid carcinoma; HPTH = primary hyperparathyroidism; Ph = pheochromocytoma; VD = vitamin D supplements; y = years)”

 

 Provide more details on long-term follow-up and outcomes, including quality of life after surgery.

Thank you very much. We added these data. Thank you

“On the other hand, we should mention that the surgeries’ impact on the overall quality of life should be carefully taken into consideration since lifelong levothyroxine replacement is necessary following total thyroidectomy, respectively, glucocorticoids and fludrocortisone administration after bilateral adrenalectomy for bilateral pheochromocytoma. Post-operative hypoparathyroidism, as shown above, also requires long term vitamin D and calcium supplements. So far, the studies with respect to the quality of life in this hereditary aliment are limited and the dermatologic involvement brings an additional burden to the overall picture. The aggressiveness of the medullary thyroid carcinoma remains the main contributor to the syndrome-related mortality, including in younger patients. Philological support across life span and surveillance at multidisciplinary specialized centers with regard to the specific protocols might improve the outcome [51-53].” 

 Expanding the discussion on therapeutic approaches for lichen amyloidosis:

e.g. 10.3390/diseases12050094

Thank you very much. We added this data and mentioned dupilumab as a modern therapeutic option for lichen amyloidosis. Thank you

 Explain the impact of family members' refusal of the genetic test on the overall results.

Thank you very much. We added these data. Thank you

“Also, the impact of the family members' refusal of the genetic testing on the overall results might not show the exact rate of association with regard to the skin involvement in this hereditary syndrome. The long term effects of untreated medullary thyroid carcinoma and pheochromocytoma are dramatic such as local and distant malignancy spreading, respectively, acute cardiovascular and neurological events (e.g. stroke, severe high blood pressure, acute myocardial infarction, etc.), diabetes or hypertension-related chronic kidney disease. In addition, the lack of testing the children of these family members might show a similar negative impact, noting there is a 50% risk of syndrome inheritance [4,5]”

 Reinforce discussion of potential mechanisms linking RET mutations to lichen amyloidosis.

Thank you very much. According to your recommendation, we expanded these data and added a new figure. Thank you

 Correct minor grammatical errors to ensure clarity and accuracy.

Thank you very much. We corrected them.

Thank you very much.